串联蓄电池组均衡充电系统

分析了蓄电池不一致性的原因,在此基础上,设计了一种简单、实用、高效的均衡充电系统。在电池组充电时实施PWM分流,实时监测控制各单体的工作情况。通过独立均衡模块,实现蓄电池组的均衡充电,克服单体间的不一致性。该方法可大大延长电池的使用寿命,实验验证了该方案的可行性。     

On learning and development, Piagetian style: I. A reply to Lefebvre-Pinard.

Examines the equilibration theory of Piaget (learning vs development, stage transitions) to make more explicit the methodological foundations of B. Inhelder et al (1974). In this connection, the "problem-solving" learning method used by these authors is analyzed by means of the new concept of "learning loops." Similarly, the successful equilibration learning method used by M. Lefebvre and A. Pinard (1974) is analyzed and shown to involve executive facilitation and chunking (coordination) of 2 crucial schemes. A process-structural model of conservation acquisition previously developed by the present author, and its empirical tests by R. Case (1975) and by G. M. Parkinson (1975), are used to illustrate and to empirically support the process-structural differences theoretically found between these 2 equilibration methods. (54 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Corrosion-resistant analogue of Hadfield steel

The concept of alloying austenitic steels with carbon + nitrogen is used for the development of a corrosion-resistant austenitic CrMn steel having an impact wear resistance close to that of the Hadfield steel. A higher stabilization of the austenitic phase by C + N, as compared to carbon or nitrogen alone, is substantiated by ab initio calculation of the electron structure, measurements of the concentration of free electrons and calculations of the phase equilibrium. Based on these results, the compositions (mass%) Cr18Mn18C0.34N0.61 and Cr18Mn18C0.49N0.58 were melted and tested along with Hadfield steel Mn12C1.2. Mechanical tests have shown that, as compared to the Hadfield steel, the experimental steels possess a higher strength, plasticity, hardness and the same resistance to impact wear. TEM studies of the surface layer after impact treatment revealed a mixture of the amorphous phase, nanocrystals and fine-twinned austenite. At the same time, using Mössbauer spectroscopy of conversion electrons, the ferromagnetic ordering was found in the surface layer of up to 10 μm in depth, which is the sign of the strain-induced martensitic phase. The hypothesis of a transition from the low-spin to the high-spin state of the iron atoms within the thin twins in austenite was proposed in order to interpret the discrepancy between TEM and Mössbauer studies. Potentiodynamic measurements and immersion tests show that the CrMnCN steels possess a significantly higher pitting potential and resistance to general corrosion in comparison with Hadfield steel.     

基于网格环境的资源管理模型研究

针对目前网格环境下资源管理存在的问题和现状，提出了一种基于市场机制的资源管理模型。该模型以一般均衡理论为基础，计算出资源的市场价格，依靠市场机制，实现计算网格资源的优化分配。     

基于状态反馈和参数调整稳定混沌系统的不稳定平衡点

针对OGY方法需要预先找到系统的一个可调参数的不足，基于状态反馈和参数调整，提出了稳定混沌系统不稳定平衡点的一种简单控制方法．根据线性控制理论选择控制参数，并研究了设计控制参数的准则．该方法不需系统的动力学知识，也不需要系统内部的任何控制参数．仿真结果验证了该方法的有效性．     

含化学反应体系多相平衡计算方法的研究进展

首先给出了含化学反应体系多相平衡计算问题的数学方程，然后对国内外含化学反应体系多相平衡计算方法的现状和进展做了综述，包括经典的非化学计量系数法和化学计量系数法以及最近提出的稳定性分析法、全局最优法和遗传算法等，并具体介绍了化学计量系数法中两种常用算法-S-C算法和KZ算法以及遗传算法的算法原理和计算步骤。     

Coordination in networks: An economic equilibrium analysis

Networks utilizing modern communication technologies can offer competitive advantages to those using them wisely. But due to the existence of network effects, planning and operating cooperation networks is difficult. In this paper, the strategic situation of individual agents deciding on network participation is analysed. A systematic equilibrium analysis using computer-based simulations reveals principal solution scenarios for network agents and shows that network cooperation problems might frequently be not as difficult to resolve as often feared. In particular, strategic situations are identified showing that a majority of individuals might be better off getting the optimal solution from a central principal and that in many cases simple information intermediation can solve the start-up problem notorious in network economics.     

The Complete Solution of the Competitive Rank Selection Problem

Two decision-makers A and B observe sequentially a given permutation of n uniquely rankable options. A and B have one choice each (without recall) and both must make a choice. At each step only the relative ranks are known, and A has the priority of choice. At the end the (absolute) ranks are compared and the winner is the one who has chosen the better rank. Extending results by Enns and Ferenstein [6] and Berry et al. [1] this article gives, for both A and B , the optimal strategy and the corresponding winning probabilities. We show in particular that the limiting winning probabilities for A and B do exist, which closes a most important gap in the work of previous authors. This also provides an algorithm for numerically computing the limiting value of these probabilities. Although our proof is analytic in a strong sense, it is interesting to see that it would have been very hard to assemble it without the help of computer algebra. The reason is that the functions we have to investigate display subranges of indices which contrast considerably with respect to error terms when certain terms are replaced by approximations, and that computations were very helpful to locate those ranges where a particularly fine tuning of error estimates turned out to be indispensable. Received October 1997; revised March 15, 1998.     

Conjectural Equilibrium in Multiagent Learning

Learning in a multiagent environment is complicated by the fact that as other agents learn, the environment effectively changes. Moreover, other agents' actions are often not directly observable, and the actions taken by the learning agent can strongly bias which range of behaviors are encountered. We define the concept of a conjectural equilibrium, where all agents' expectations are realized, and each agent responds optimally to its expectations. We present a generic multiagent exchange situation, in which competitive behavior constitutes a conjectural equilibrium. We then introduce an agent that executes a more sophisticated strategic learning strategy, building a model of the response of other agents. We find that the system reliably converges to a conjectural equilibrium, but that the final result achieved is highly sensitive to initial belief. In essence, the strategic learner's actions tend to fulfill its expectations. Depending on the starting point, the agent may be better or worse off than had it not attempted to learn a model of the other agents at all.     

The Value of Temptation

There is an implicit assumption in electronic commerce that induces the buyers to believe that their deals will be handled appropriately. However, after a seller has already committed to a buyer, he may be tempted by several requests though he will not be able to supply them all. We analyze markets in which a finite set of automated buyers interacts repeatedly with a finite set of automated sellers. These sellers can satisfy one buyer at a time, and they can be tempted to break a commitment they already have. We have found the perfect equilibria that exist in markets with a finite horizon, and with an unrestricted horizon. A significant result stemming from our study reveals that sellers are almost always tempted to breach their commitments. However, we also show that if markets' designers implement an external mechanism that restricts the automated buyers actions, then sellers will keep their commitments.