基于eM-Plant的柔性生产调度仿真研究

车间生产调度是流水制造企业运行管理的核心,针对流水车间工件多样化、多机调度平行化的作业特点,在分析系统逻辑流程和运行机理的基础上,用em-plant软件建立仿真模型,通过SimTalk语言程序触发仿真事件和监控仿真状态。分析工件加工时间、到达率及加工工序对调度结果的影响,以零件平均等待时间、资源利用率和置信度为系统评价指标。仿真结果表明,在确定加工工序和加工时间条件下,生产调度方案是合理的。     

Whether crop diversification is a desired strategy for agricultural growth in Bangladesh?

This study aimed at examining the merit of crop diversification as a strategy for agricultural growth in Bangladesh. Specifically, the existence of economies of diversification, scale economies and diversification efficiencies at the farm level were examined using a stochastic input-distance function approach. The results reveal strong evidence of diversification economies amongst most crop enterprises except the combination of modern rice and modern wheat enterprises. Ray economies of scale exist in Bangladeshi cropping system. Also, significant are efficiency gains made from diversification among cropping enterprises. The key policy implication is that crop diversification should be a desired strategy for agricultural growth in Bangladesh. Development of the rural infrastructure is also essential as this will not only improve technical efficiency but may also synergistically promote crop diversification by opening up opportunities for technology diffusion, marketing, storage and resource supplies.     

Is there one safe-haven for various turbulences? The evidence from gold,Bitcoin and Ether

This paper aims to investigate the safe-haven properties of gold and two cryptocurrencies, Bitcoin and Ether. Safe havens are the financial assets that allow investors to protect their portfolios within the market turmoil. The research sample covers five years and includes several downturns on the financial markets, starting from the Chinese stock market turbulences in 2015/2016 and ending up with the recent pandemic outbreak in 2020. We find that only gold used to be a strong safe-haven against the stock market indices. Yet, this property evaporated during the crisis caused by the COVID pandemic. Occasionally, cryptocurrencies could have been considered weak safe-havens against the examined instruments. Ether acted more often as a weak safe-haven against DAX or S&P500, while Bitcoin played this role against FTSE250, STOXX600 and S&P500.     

Generalised weakened fictitious play

A general class of adaptive processes in games is developed, which significantly generalises weakened fictitious play [Van der Genugten, B., 2000. A weakened form of fictitious play in two-person zero-sum games. Int. Game Theory Rev. 2, 307–328] and includes several interesting fictitious-play-like processes as special cases. The general model is rigorously analysed using the best response differential inclusion, and shown to converge in games with the fictitious play property. Furthermore, a new actor–critic process is introduced, in which the only information given to a player is the reward received as a result of selecting an action—a player need not even know they are playing a game. It is shown that this results in a generalised weakened fictitious play process, and can therefore be considered as a first step towards explaining how players might learn to play Nash equilibrium strategies without having any knowledge of the game, or even that they are playing a game.     

Rigid wage-setting and the effect of a supply shock,fiscal and monetary policies on Chinese economy by a CGE analysis

The purpose of this paper is to present a computable general equilibrium (CGE) model of the Chinese economy which includes rigid wage-setting and integration of real and financial sectors, and to apply it to a quantitative evaluation of the oil price changes and the fiscal and monetary policies. The policy simulation shows whether the wage rate is flexible or rigid is crucial for the evaluation of various policy measures. Furthermore, the fields of application of the model are extended from the industry-related problems to the macroscopic ones such as inflation, stabilization policies and so on.     

“潮涌现象”中单位产能成本对均衡产能影响的模拟研究

从演化博弈模拟的角度,专门探讨在投资“潮涌现象”中单位产能成本这一因素对对称均衡产能的影响。模拟结果表明,单位产能成本的增加,使得对称均衡产能减少。     

Equilibrium play in matches: Binary Markov games

We study two-person extensive form games, or “matches,” in which the only possible outcomes (if the game terminates) are that one player or the other is declared the winner. The winner of the match is determined by the winning of points, in “point games.” We call these matches binary Markov games. We show that if a simple monotonicity condition is satisfied, then (a) it is a Nash equilibrium of the match for the players, at each point, to play a Nash equilibrium of the point game; (b) it is a minimax behavior strategy in the match for a player to play minimax in each point game; and (c) when the point games all have unique Nash equilibria, the only Nash equilibrium of the binary Markov game consists of minimax play at each point. An application to tennis is provided.     

创新孵化网络演化无标度特征仿真分析

在考虑节点间的关系强度和节点强度承载力的基础上,通过改进BA无标度模型来模拟创新孵化网络演化过程,并利用Matlab仿真技术分析得出创新孵化网络具有无标度特征,主要体现为异质性、集聚性、网络鲁棒性和网络脆弱性。     

线性预测模型的分布估计

本文讨论把线性预测模型修改成势分析预测模型,并用数值模拟方法给出预测值分布的方法。     

京石客专声屏障桩基础受力特性数值分析

运用ABAQUS软件对京石客专声屏障桩基础在竖向荷载作用下的受力特性进行三维模拟,分析采用不同的桩长、桩径、桩身混凝土情况下,重点分析桩顶的位移和桩身内力的大小及分布规律。结果表明:本桩基础的竖向承载力很大,桩径的大小对桩的沉顶沉降影响比较大,桩长的大小对桩的沉降有一定的影响,桩身混凝土的强度对桩顶沉降影响较小。