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1.
J.L. Finck 《Journal of The Franklin Institute》1948,245(4):301-317
In this paper the concepts “equilibrium” and “reversibility” are examined from the standpoint of the number of independent variables which define a thermodynamic system. The endeavor is made to show that the number of independent variables which are selected is crucial to the basic concepts as well as to the second law of thermodynamics. If this number is less than the minimum required to define the system completely, the equation of state for the internal energy will be incomplete. It is our practice to employ incomplete equations of state, and this results in processes which we consider to be irreversible. The Kelvin-Planck and Clausius principles are shown to be somewhat related to the first law of thermodynamics, and their validity arises from the fact that the equations of state which are used are incomplete. If these equations were complete, that is, if the number of independent variables were not less than the minimum required to describe the systems completely, we should have complete conversion of heat into work, as well as work into heat. The difficulties in realizing complete equations are considered.The entropy concept is considered in detail, and it is shown that there are serious limitations in its application. 相似文献
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Zhipeng Li Minyue Fu Huanshui Zhang Zongze Wu 《Journal of The Franklin Institute》2018,355(12):5240-5255
In this paper, we consider a stochastic linear quadratic mean field game for the continuum-parameterized multi-agent systems with multiplicative noise. Based on the Nash certain equivalence principle, we obtain a series of decentralized control laws. Then, Dynkin’s formula and comparison principle are employed to prove the boundedness of the state of the closed loop system in the mean square sense. Finally, we show that the set of decentralized controls has an ?-Nash equilibrium property. 相似文献
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In this paper, a system of thermodynamic relations governing the deformation of strain-rate sensitive elastic-plastic materials is developed. These relations are obtained by assuming that the deformation and entropy of the material are dependent on stress state and temperature, and on certain internal variables which are identified in this paper with dislocation densities, and the mobile fractions of each kind of dislocation. It is postulated (on the basis of physical arguments) that the densities and fractions are governed by certain evolutionary equations. An example is given of a material that derives from these evolutionary equations under quite simple assumptions. It is shown by numerical calculations that this material exhibits the main features observed experimentally in uniaxial stress tests of metals. 相似文献
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《Journal of The Franklin Institute》2022,359(18):10628-10652
Control of a water hyacinth-fish ecological system is required for a healthy and sustainable environment. This paper aims to investigate the global dynamics of a water hyacinth fish ecological system under ratio-dependent state impulsive control. First, we study the positivity and boundedness of the solution of the controlled system. By studying the local stability of the equilibrium, we find that the system has two situations. One is that there are two equilibria, namely a saddle point and a boundary equilibrium. In the second case, there are four equilibria, namely, two saddle points, a boundary equilibrium, and a focus point. For the first case, when we select an appropriate ratio-dependent control threshold, the trajectory will globally converge to the boundary equilibrium. For the second case, when the control line is located below the focus point, by using Poincare mapping method, flip bifurcation theory, and vector field analysis techniques, we find that the solution of the controlled system either globally converges to the boundary equilibrium, order-1 periodic solution, or order-2 periodic solution under certain conditions. When the control line is located above the focus point, the solution of the controlled system either globally converges to the focus point, order-1 or order-2 periodic solution. Finally, we use examples to verify the correctness and validity of the theoretical results. 相似文献
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石油资源危机与石化企业倒闭的动力学机制 总被引：1，自引：1，他引：0
该文建立了石油资源短缺下国际石化企业竞争的非线性动力学模式,揭示了倒闭的大型石化企业数与石油短缺率的内在约束关系以及石化企业倒闭数与最强（大型）石化企业对石油占有率的内在约束关系。研究结果表明,对于D>q,即石油的短缺率大于国际石化系统最强（大型）石化企业对国际石油市场和资源的占有率,石化企业的演化存在以下规律和特点：（1）石化系统里的最强（大型）石化企业n1将不可避免地倒闭。随着石油短缺率的增加,伴随最强（大型）石化企业走向倒闭的石化企业依次是第二、第三、第四、……强（大型）的石化企业,D/q的值越大型,石化系统所倒闭的大型石化企业数越多。倒闭的驰豫时间量级为50d—500d左右; （2）短缺石油后的幸存石化企业将经历三个演变阶段： 抵抗阶段,恢复阶段和稳定阶段。经过多平衡态共存和最强（大型）石化企业的不断替代过程后,国际石化企业系统达到新的平衡态,此时石化系统企业强弱的序严格地遵守偶数-奇数对称或奇数-偶数对称规律。即如果由于石油的短缺而导致系统有奇数个石化企业倒闭,则适应稳定后的系统的石化企业的强弱序服从偶数-奇数对称规律,即原序号为偶数的石化企业为强（大型）者,而原序号为奇数的石化企业为弱者。如果系统有偶数个石化企业倒闭,则适应稳定后的系统的石化企业的强弱序服从奇数-偶数对称规律,即原序号为奇数的石化企业为强（大型）者,而原序号为偶数的石化企业为弱者。所以,对于依赖于石油的各类不同的石化企业,把握石油的短缺率及石化系统最强（大型）企业对国际石油市场和资源的占有率十分重要。 相似文献
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This paper investigates the robustness, uniqueness, sufficient condition and the necessary condition for the minimum error entropy (MEE) estimation. For the robustness aspect, we show that the MEE estimator for a Gaussian nominal model is robust with respect to a relative entropy mismodeling criterion as well as the minimum mean-square error (MMSE) estimations. For the uniqueness aspect, we demonstrate by means of examples that for the singular case, the optimum solution of the MEE estimation will be nonunique. For the sufficient and the necessary condition, the former is established by the independence condition, and the later by score orthogonality condition. A specific example illustrates that the score orthogonality condition is just a necessary condition and not a sufficient one, because if an estimator satisfies the score orthogonality condition, it may be a local minimum or even a local maximum of the error entropy in a certain direction. 相似文献
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This paper investigates the chaos control problem of a new multi-scroll chaotic system. Two nonlinear control methods are studied, namely high-order and predictive types of control. The proposed methodologies offer the possibility of stabilizing unstable periodic orbits and unstable equilibrium points from the state equations. For this purpose, we apply the high-order control method for stabilizing a desired unstable periodic orbit, while the predictive control method is applied for stabilization problem of unstable equilibrium points. In particular, these approaches are effective and easy to be implemented since we only need to apply small perturbations to the system dynamics. The multi-scroll Chen system is used as representative example to show the working principle of these methods. Numerical simulation results indicate the potential engineering applications of the proposed control methods for various multi-scroll chaos-based practical applications. 相似文献
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Nzeqqe Chantale Ebude Wang Mingyan 《科技广场》2007,(7):6-8
Most traffic control systems available in major cities in Cameroon are still out dated, make use of theories and models which are very slow to implement, waste resources and their efficiency is very low. Thus the number of road accidents encountered on our major highways and inter urban traffic networks has been increasing despite the various efforts made by government and certain NGO to synthesize road users on certain aspects of traffic control and safety road use. Taxis are not left out in the whole show and most of the blame always falls on them. The need to use available Information and Communication Technology ICT to improve on the control of traffic in inter urban cities and major highways is imperative. ITS optimizes the use of resources, reduce pollution, contribute to environmental protection and increases the national economy. . This paper starts by giving a brief situation of the transportation system in Cameroon, its drawbacks and proposes an optimized ITS based system. 相似文献
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基于信息熵的江苏省耕地安全系统演化分析 总被引：5，自引：0，他引：5
基于耕地安全系统理论和耗散结构理论,构建了耕地安全系统演化分析的指标体系,建立了评估耕地安全系统演化的量化模型。应用该模型纵向评价了江苏省1998年～2004年耕地安全系统演化状况。研究发现：①耕地安全系统变化的社会经济压力熵和支持型熵变化明显,数量变化熵由正熵演变为负熵,质量变化熵接近于0,生态环境变化熵表现为波动状态,系统总熵变由正变为负;②耕地安全系统熵流的发展度和协调度差异显著,数量变化和质量变化发展度处于发展的高级阶段并且趋于下降,生态环境发展度由中级发展状态发展到高级发展状态,处于上升阶段。就协调度而言,数量变化和质量变化比较平稳,生态变化波动较大。协调侧重度也表现不一,数量变动协调度由强社会经济压力型变为强支持型,质量变化协调度由中等支持型变为中等压力型,生态变化协调度由中等社会经济压力型变为强支持型。评价结果表明：江苏省耕地安全系统发展目标逐渐明确、有序度不断增强;耕地安全系统的健康、有序水平不断提高,协调能力不断增强,系统活力有待改善。 相似文献
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Andrea L׳Afflitto 《Journal of The Franklin Institute》2017,354(1):456-478
In this paper, we develop a unified framework to find state-feedback control laws that solve two-player zero-sum differential games over the infinite time horizon and guarantee partial-state asymptotic stability of the closed-loop system. Partial-state asymptotic stability is guaranteed by means of a Lyapunov function that is positive definite and decrescent with respect to part of the system state. The existence of a saddle point for the system?s performance measure is guaranteed by the fact that this Lyapunov function satisfies a partial differential equation that corresponds to a steady-state form of the Hamilton–Jacobi–Isaacs equation. In the second part of this paper, we show how our differential game framework can be applied not only to solve pursuit-evasion and robust optimal control problems, but also to assess the effectiveness of a model reference adaptive control law. Specifically, the model reference adaptive control architecture is designed to guarantee satisfactory trajectory tracking for uncertain nonlinear dynamical systems, whose matched nonlinearities are captured by the regressor vector. By modeling matched and unmatched nonlinearities, which are not captured by the regressor vector, as the pursuer?s and evader?s control inputs in a differential game, we provide an explicit characterization of the system?s uncertainties that do not disrupt the trajectory tracking capabilities of the adaptive controller. Two numerical examples illustrate the applicability of our results. 相似文献
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首先运用流程图法分析造成物联网环境下医药冷链物流各环节风险的众多因素源,并运用熵权法对风险指标客观赋权建立风险因素评估指标体系,然后利用Ge NIe软件建立动态贝叶斯网络模型对风险环节的关键风险因素进行概率评估。结果显示在风险评估中运输环节风险的发生概率最高,同时企业关于设备的验证选型是影响物联网医药冷链的关键风险因素,这为企业和政府控制药品质量安全管理提供了依据。 相似文献
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《Journal of The Franklin Institute》2022,359(12):6099-6122
With the fast development of the economy, marine activities are increasing. Due to the advantages of offshore cranes, they are widely used in marine production as effective transportation tools. As a matter of fact, the offshore crane works on the ship known as a typical noninnertial system, which is affected by the ship movement. To tackle this problem, we propose a time optimal trajectory planning method for the considered offshore crane. Specifically, to tackle the couplings between state variables, we show that the offshore crane system is differentially flat with the payload coordinates as the flat outputs. Based on this fact, the planning problems for the jib motion and the rope length are further converted into the planning problems for flat outputs. Then, in order to ensure the trackability of the planned trajectory and improve the safety, we consider a series of physical constraints including the jib luffing motion velocity and acceleration constraints, the rope length varying velocity and acceleration constraints, and the payload swing angle and angular velocity constraints, and then a time optimization problem is further formulated. By utilizing a bisection-based method, the optimal payload transportation time is obtained as well as the corresponding time optimal trajectories. As far as we know, it is the first time optimal trajectory planning method designed for offshore cranes to achieve the fast and accurate payload transportation as well as the payload swing elimination in earth-fixed frame. At last, the effectiveness of the proposed method is verified by simulation tests. 相似文献
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倒立摆系统本身是一个非线性控制系统,具有多变量、高阶次、强耦合以及严重不稳定的特点。主要任务是设计一个基于PID算法的旋转倒立摆控制系统,利用单片机运用PID算法对系统进行控制,能够使旋转倒立摆的摆杆快速达到倒立平衡状态并具有一定的抗干扰能力。 相似文献
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技术创新对地区经济发展具有重要的推动作用,是提高创新能力和强化核心竞争力的关键途径。立足于知识聚合视角,在分析技术创新熵变和突变特性的基础上,对技术创新形成机理进行隐喻分析;借鉴突变理论中的尖点突变模型构建技术创新形成机理模型,并选取系统内部知识为状态变量,系统外部知识引起的负熵和系统内部知识引起的熵增为控制变量,深入分析技术创新的形成机理。研究表明：技术创新形成机理由技术创新孕育阶段、渐进性技术创新形成阶段和突破性技术创新形成阶段三个环节构成。最后从构建系统内部知识共享机制、增加系统外部知识引入、建立系统内外部知识聚合机制及完善技术创新支撑体系四个方面,提出了促进技术创新形成的相关策略。 相似文献
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为准确把握湖南省土地市场发育状况,本文紧扣土地市场发育的内涵,从土地市场交易情况、土地市场供求均衡度、土地市场地价敏感度、土地市场竞争度、土地市场政府干预度5个方面入手,构建起包含11个单项指标的土地市场成熟度评价指标体系,尝试运用熵权可拓物元模型,定量评价2012年湖南省土地市场成熟度。结果表明:1总体上看,湖南省土地市场成熟度处于"过渡期",并有向"成熟期"转变的趋势;2就单个评价指标而言,土地闲置率、土地价格供给弹性、土地税收占财政收入比重、协议地价与出让地价差额率等4个指标处于"成熟期",土地转让率、土地供给率、土地价格需求弹性、地价弹性系数、土地投资来源多样化率等5个指标处于"过渡期",土地出让金溢出率、土地有偿出让率2个指标分别处于"发展期"和"发育期";3熵权可拓物元模型在土地市场成熟度评价方面实用可行,评价结果符合湖南省土地市场发育的实际,为同类研究提供了方法上的支持。 相似文献
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组织能力是企业、产业、区域、以及一个国家持续竞争优势的基础，研究组织能力具有重要的现实意义和学术价值。论文研究企业组织能力问题，根据系统涌现原理建构了企业组织能力系统涌现的概念模型,并且基于信息熵理论构建了企业组织能力系统涌现性度量模型和指标体系，用以测度企业组织能力系统的涌现强度。此外，以昆明云内动力股份有限公司为案例，根据云内动力的具体情况确定了22个度量指标，通过访谈法、问卷法、文本分析等方法收集了2008-2012年期间的指标数据以进行实证研究。研究表明：基于信息熵的企业组织能力系统涌现性度量模型可用于测度企业组织能力生成的强弱，尤其适用于动态复杂、超强竞争、充满不确定性的全球竞争环境。 相似文献
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《Journal of The Franklin Institute》2019,356(12):6175-6207
In this paper, we consider leader–follower decentralized optimal control for a hexarotor group with one leader and large population followers. Our hexarotor is modeled based on the quaternion framework to resolve singularity of the rotation matrix represented by Euler angles, and has 6-DoF due to six tilted propellers, which allows to control its translation and attitude simultaneously. In our problem setup, the leader hexarotor is coupled with the follower hexarotors through the followers’ average behavior (mean field), and the followers are coupled with each other through their average behavior and the leader’s arbitrary control. By using the mean field Stackelberg game framework, we obtain a set of decentralized optimal controls for the leader and N follower hexarotors when N is arbitrarily large, where each control is a function of its local information. We show that the corresponding decentralized optimal controls constitute an ϵ-Stackelberg equilibrium for the leader and N followers, where ϵ → 0 as N → ∞. Through simulations with two different operating scenarios, we show that the leader–follower hexarotors follow their desired position and attitude references, and the followers are controlled by the leader while effectively tracking their approximated average behavior. Furthermore, we show the nonsingularity and 6-DoF control performance of the leader–follower hexarotor group due to the novel modeling technique of the hexarotor presented in the paper. 相似文献