系统动态仿真在运载火箭多项目批产计划管理中的应用分析

我国"长征"系列运载火箭在经历了单发和小批量研制生产阶段后已进入了批产阶段,"十一五"期间年均发射密度将达到10发,其科研管理方法正在从型号或项目管理向多项目管理,从单一项目的关键路径控制向多项目的资源优化统筹过渡.因此需要对过去以单发产品为主的管理模式和方法作必要的改进和完善,以适应因任务和发射密度增加所带来的新形式.     

A Nonlinear Model of the Term Structure of Interest Rates

We present an economically motivated two–factor term structure model that generalizes existing stochastic mean term structure models. By allowing a certain parameter to acquire dynamical behavior we extend the two–factor model to obtain a nonlinear three–factor model that is shown, in a deterministic version, to be equivalent to the Lorenz system of differential equations. With reasonable parameter values the model exhibits chaotic behavior. It successfully emulates certain properties of interest rates including cyclical behavior on a business cycle time scale. Estimation and pricing issues are discussed. Standard PCA techniques used to estimate HJM type models are observed to be equivalent to dimensional estimates commonly applied to 'spatial data' in nonlinear systems analysis.
It is concluded that techniques commonly used in the analysis of nonlinear systems may be directly applicable to interest rate models, offering new insights in the development of these models. Tests of nonlinearity in interest rate behavior may need to focus on long cycle times.     

An Experimental Study of Statistical Discrimination by Employers

This article reports findings of an experiment motivated by a dynamic labor market model that considers the problem faced by employers in making hiring decisions between workers of different types. The question examined here is how quickly employers learn about the ability of a group of workers through observing representatives of that group. If prior opinions are weak, the employer will use Information from the workplace to quickly update any incorrect group-based stereotypes it may have. On the other hand, if priors are heavily weighted, incorrect initial perceptions will result in persistent wage differences. Our experimental findings are twofold. First, subjects' (employers') behavior moves quickly toward optimal choices. Second, strong priors are hard to establish. These results suggest that it would take a long time for employers to form group-based stereotypes and that such stereotypes should go away quickly in response to signals that contradict these stereotypes.     

Is It Who You Know? Entrepreneurs and Bankers in Sao Paulo, Brazil, at the Turn of the Twentieth Century

This article examines the trust-producing mechanisms investorsand financiers used in São Paulo, Brazil, to determinewhere to invest their money in the late nineteenth and earlytwentieth centuries. The coffee boom that began in the 1880sspurred bursts of new domestic business development that transformedSão Paulo into Brazil's industrial leader. Using shareholderand director data from an array of business sectors, this articledemonstrates that early development (1856–1905) of theinstitutions that provided business finance was accompaniedby highly personal relationships between financier and entrepreneur.By the early twentieth century (1906–1920), rapid economicgrowth and business diversification rendered these personalconnections inadequate and hence less important to businessfinance. Investors and directors concentrated their energiesand their money, abandoning the practice of forming broad connectionsin general—and connections to a bank in particular—andturned to the stock market instead. By providing an alternativeto personal forms of trust production, the rise of impersonalintermediation promoted the significantly broadened market forcorporate business formation that underwrote São Paulo'seconomic transformation.     

government and the PSBR

The government has changed its view of how to gauge the size of the budget deficit. Nick Parsons and David Coleman, of Union Discount, argue that this change is an ill-omen for the control of public spending.     

The false promise of technological determinism: the case of enterprise resource planning systems

According to software vendors and consultants, Enterprise Resource Planning systems (ERPs) transform the nature, structure and management of work regardless of organisational context. This paper contests this technologically deterministic view of organisational change by demonstrating the role that discourse plays in the social construction of ERPs.