电动搬运车辆斩波器的应用分析

介绍以蓄电池和串励直流电动机为动力的电动搬动车辆用斩波器的种类，型号，参数，电路原理和应用情况。     

基于网格技术的城市公共汽车到站时刻预测研究

在介绍了网格技术的含义和基础知识后,结合我国目前公共汽车预测研究的现状,设计了基于网格技术的城市公共汽车到站时间的预测系统,并对其进行了详细的设计。     

智能化立体车库优化车辆存取策略研究

通过对智能化立体车库的研究，提出了三种可提高车库效率的优化车辆存取策略，即分区存取、交叉存取和自调整策略。     

A Note on Minimax Mixture of Distributions Free Procedure for Inventory Model with Variable Lead Time

In recent papers, Moon and Choi (1998) and Hariga and Ben-Daya (1999)considered a continuous review inventory model with a mixture of backordersand lost sales in which the lead time, the order quantity, and the reorder pointare decision variables was studied. Moreover, they also develop a minimaxdistribution free procedure for the problem. While the demands of differentcustomers are not identical in the lead time, then we can't only use a singledistribution (such as Moon & Choi (1998) and Hariga & Ben-Daya (1999))to describe the demand of the lead time. Hence, we correct and extend the modelof Moon and Choi (1998) and Hariga and Ben-Daya (1999) by considering thelead time demand with the mixture of distributions. In addition, we also applythe minimax mixture of distributions free approach to the model by simultaneouslyoptimizing the order quantity, the reorder point, and the lead time to devise a practical procedure which can be used without specific information on demand distribution.     

基于时间约束的多源多品种随机配送系统模型

在基于时间竞争的随机需求环境下,配送系统设计除了使系统总费用的期望值最小外,还要考虑系统稳定性和服务水平等方面的要求。在说明了建模的假设条件后,建立了考虑随机需求和时间约束的多源配送系统随机模型。通过等价变换,将随机模型转化为确定性等价问题,从而方便了问题的求解。     

Declining Discount Rates: The Long and the Short of it

The last few years have witnessed important advances in our understanding of time preference and social discounting. In particular, several rationales for the use of time-varying social discount rates have emerged. These rationales range from the ad hoc to the formal, with some founded solely in economic theory while others reflect principles of intergenerational equity. While these advances are to be applauded, the practitioner is left with a confusing array of rationales and the sense that almost any discount rate can be justified. This paper draws together these different strands and provides a critical review of past and present contributions to this literature. In addition to this we highlight some of the problems with employing DDRs in the decision-making process, the most pressing of which may be time inconsistency. We clarify their practical implications, and potential pitfalls, of the more credible rationales and argue that some approaches popular in environmental economics literature are ill-conceived. Finally, we illustrate the impact of different approaches by examining global warming and nuclear power investment. This includes an application and extension of Newell and Pizer [‘Discounting the benefits of climate change mitigation : how much do uncertain rates increase valuations?’ Journal of Environmental Economics and Management 46 (2003) 52] to UK interest rate data.     

基于提前期和价格折扣的延迟交货和库存策略研究

研究了基于提前期和价格折扣的延迟交货和库存策略,其中的价格折扣是基于提前期的价格折扣,即当出现缺货而不能在既定的提前期内交货时,企业就会提供一个价格折扣,这时会有一部分顾客愿意等待,直到订单被满足,即延迟交货。其中,愿意等待延迟交货的比例跟提前期成反比关系,提前期的各部分都可以通过增加成本来实现压缩。     

Modelling of repairable systems with various degrees of repair

The availability of a stochastic repairable system depends on the failure behaviour and on repair strategies. In this paper, we deal with a general repair model for a system using auxiliary counting processes and corresponding intensities which include various degrees of repair (between minimal repair and perfect repair). For determining the model parameters we need estimators depending on failure times and repair times: maximum likelihood (ML) estimator and Bayes estimators are considered. Special results are obtained by the use of Weibull-type intensities and random observation times.     

Seasonal decomposition and forecasting of telecommunication data: A comparative case study

In this paper, forecasting models for the monthly outgoing telephone calls in a University Campus are presented. The data have been separated in the categories of international and national calls as well as calls to mobile phones. The total number of calls has also been analyzed. Three different methods, namely the Seasonal Decomposition, Exponential Smoothing Method and SARIMA Method, have been used. Forecasts with 95% confidence intervals were calculated for each method and compared with the actual data. The outcome of this work can be used to predict future demands for the telecommunications network of the University.     

Can intertemporal choice experiments elicit time preferences for consumption?

The paper considers what can be inferred about experimental subjects’ time preferences for consumption from responses to laboratory tasks involving tradeoffs between sums of money at different dates, if subjects can reschedule consumption spending relative to income in external capital markets. It distinguishes three approaches identifiable in the literature: the straightforward view; the separation view; and the censored data view. It shows that none of these is fully satisfactory and discusses the resulting implications for intertemporal decision-making experiments. JEL Classification C90, C91, D90, D91, D11, D12