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.     

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     

Timing and Commitment of Environmental Policy,Adoption of New Technology,and Repercussions on R&;D

We investigate the interplay between environmental policy, incentives to adoptnew technology, and repercussions on R&D. We study a model where a monopolistic upstream firm engages in R&D and sells advanced abatement technology to polluting downstream firms. We consider four different timing and commitment regimes of environmental tax and permit policies: ex post taxation (or issuing permits), interim commitment to a tax rate (a quota of permits) after observing R&D success but before adoption, and finally two types of ex antecommitment before R&D activity, one with a unique tax rate (quota of permits), the other one with a menu of tax rates (permit quotas). We study the second best tax and permit policies and rank these with respect to welfare. In particular, we find that commitment to a menu of tax rate dominates all other policy regimes.     

Persistence of Shocks to Output in Austria and Theories of Economic Growth

The paper analyzes the degree of output persistence in GDP in order toempirically discriminate between the Solow growth model, the perfect competition endogenous growth model and the imperfect competition endogenous growth model for the case of Austria. Wefind that a shock in the growth rate of output induces a permanent and larger effect on the level of GDP. This leads us to refute the Solow growth model and the perfect competition model of endogenous growth.We may not reject the imperfect competition growth model.     

基于混合优化算法的带时间窗的车辆调度问题求解研究

论文建立了带时间窗的车辆调度问题的数学模型，并针对遗传算法在局部搜索能力方面的不足，提出将模拟退火算法与遗传算法相结合，从而构造了求解车辆调度问题的混合优化算法，并进行了实验计算。计算结果表明，用这种混合优化算法求解车辆调度问题，可以在一定程度上用模拟退火算法突跳性克服遗传算法在局部搜索能力方面的不足，从而得到质量较高的解。     

Geometrical Interpretation of the Mean and the Constant in a Box-Jenkins Time Series Model

Certain manuals and computer programs mistakenly identify the mean with the constant in Box-Jenkins time series models. In this paper, it will be shown that (a) the mean and the constant have different values in autoregressive models, and (b) they have an algebraic and graphical relationship.     

Time variation in the cointegrating relationship between stock prices and economic activity

The present paper examines whether there exists a long‐run cointegrating relationship between a stock market index and output and interest rates. Moreover, estimation is conducted over the full sample and both a recursive and rolling sample to examine any time variation in the nature of the relationship. The results support evidence of a single cointegrating vector, where stock prices typically exhibit a positive relationship with industrial production and a negative relationship with interest rates. However, there is significant time variation and periods of time where contrary results are observed. As such any model of stock prices needs to account for such time variation     

生产劳动力的劳动时间的探讨

传统经济学的劳动力价值理论只有生产劳动力的生产费用(物化劳动),没有生产劳动力的劳动时间(活劳动)的耗费。劳动力的生产也有劳动时间的耗费。劳动力的自然再生产时间不形成劳动力的价值,劳动力的社会再生产时间、即学习劳动的时间形成劳动力的价值。劳动力价值包括两个部分:一是生产劳动力的物化劳动,如生活费用和学习费用等;二是生产劳动力的活劳动即学习劳动。     

ARIMA计量技术下河南省农民增收的预测模型研究

笔者根据河南省1978年～2005年的农民人均纯收入统计数据,将这些数据进行平稳化、零均值化处理,并利用时间序列的自相关函数,偏自相关函数的性质,确认数据所适合的模型.通过对样本数据所做的回归拟合模型定量分析,从而为河南省"十一·五"规划提供量化指标依据.     

基于大规模定制延迟制造技术的时间模型及快速响应方法研究

本文通过大规模定制生产模式的论述，指出延迟制造技术是解耦大规模定制中时间、成本和个性化的矛盾问题的较好的解决方式，并对延迟制造技术进行了新的分类。针对大规模定制的快速响应问题，提取了面向大规模定制的时间模型并进行了分析；最后指出大规模定制快速响应问题的解决方案是基于延迟制造基础上的可重组制造系统。