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81.
本文介绍了电机生产计划计算机优化系统.该系统主要由模型优化和数据处理两大部分组成,采用结构化方法进行系统分析与设计.该系统解决了合理、充分地利用有限原材料的问题,为工厂制订更合理、更科学的生产计划提供了必要的信息。  相似文献   
82.
83.
张瑞 《价值工程》2011,30(28):133-134
研究了区间时变时滞线性系统的稳定性问题,基于Lyapunov泛函方法,使用新的处理技术估计Lyapunov泛函导数的上界,以线性矩阵不等式形式给出了系统稳定性准则的改进结果。所给稳定性准则比已有结果具有更低的保守性,数值实例表明了结果的有效性。  相似文献   
84.
姚世锋  李庆泉  李献锋 《价值工程》2011,30(13):168-169
在某型高炮随动系统测试中,正弦机的发送频率直接影响着输出信号的平滑度,从而会影响测试的精度。为了避免在正弦机运行过程中,计算耗用过多机时,在正弦机发送之前,先计算出每个位置信号、前馈信号的数值,存放于内存中。本文根据该正弦机信号的特点,分析了几种正弦机角位置信号发送频率方式的优缺点,确定了正弦机发送频率的方式。  相似文献   
85.
This paper proposes a new heuristic method for the logistics network design and planning problem based on linear relaxation and DC (difference of convex functions) programming. We consider a multi-period, multi-echelon, multi-commodity and multi-product problem defined as a large scale mixed integer linear programming (MILP) model. The method is experimented on data sets of various size. The numerical results validate the efficiency of the heuristic for instances with up to several dozens facilities, 18 products and 270 retailers.  相似文献   
86.
The use of shrinkage methods for the construction of prognostic indices has been paid increasing attention in the literature on medical statistics in the last years. One approach for the construction of a shrinkage factor is cross validation calibration as suggested by van H ouwelingen and le C essie (1990). We investigate this approach in more detail. First we try to clarify why shrinkage factors constructed by cross validation calibration tend to be smaller than 1. Second we explain why use of this shrinkage factor can result in an improvement of the average prediction error. Third we investigate the possible gain for constellations relevant in medical research by means of a simulation study, focusing on the dilemma, that the improvement on average has to be paid by distinct deteriorations for some patients. Finally we conclude that it is necessary to rethink the choice of loss functions in constructing prognostic indices before recommendations about the use of shrinkage methods can be made.  相似文献   
87.
协调度是衡量系统协调程度的重要参数,将其应用到土地可持续利用评价当中,可以较好地反映土地利用系统的发展状况及可持续利用水平;采用主成分分析法、线性加权函数法和协调度指数对呼兰区(县)土地可持续利用情况及协调度进行研究。研究结果表明1994~2003年呼兰区(县)土地可持续性和协调度总体上呈逐渐上升的趋势。  相似文献   
88.
The paper presents an econometric analysis of the determinants of the financial situation in Russian manufacturing. Official statistics in Russia are not reliable. This is why the analysis is based on business opinion surveys carried out within `The Russian Economic Barometer' long-term research programme for monitoring and investigation of the transition to the market in Russia. The new adaptive approach elaborated by the author of the paper is used to form a correct set of explanatory variables in regression equations. This approach is based on the comparison of the forecast abilities of alternative models with different sets of explanatory variables. Two periods are considered and compared: January 1993 to January 1995 and February 1995 to January 1998. Two variables, the diffusion index of output and the average order-book level, provide the best explanation of the managers' judgement regarding the financial situation in Russia for the first period. It was found that for the second period, the influence of the `output index' diminished. The main factors with which managers related a `good' financial situation in their enterprises were the sample average of order-book level, the stocks of finished goods, the index of order-book level, the index of output prices ratio, and the indebtedness to banks. All relationships are presented in the context of linear probability and logit models.  相似文献   
89.
The mean squared error (MSE) of the empirical best linear unbiased predictor in an orthogonal finite discrete spectrum linear regression model is derived and a comparison with the MSE of the best linear unbiased predictor in this model is made. It is shown that under weak conditions these two mean square errors are asymptotically the same.  相似文献   
90.
In this paper, we develop a framework for evaluating the impact of conservative accounting on the structure of residual income models of equity valuation. We explore specific examples of both unconditional and conditional conservatism and observe a common mathematical structure. We proceed to generalise our model and identify the joint dependency of conservatism and the persistence of abnormal earnings on the weights attached to book values, earnings and dividends. We are able to show theoretically the likely numerical impact of conservatism on price-earnings ratios and under-valuations produced by residual income models. We investigate empirically the interaction between conservatism and persistence and find they accord well with the theory developed. We briefly discuss the implications of testing the effect of conservatism on valuation and linear information dynamics.  相似文献   
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