区间数信息下的风险投资群决策评价研究

随着中国风险投资行业不断扩张,为了避免高风险,需要多位决策人员共同参与投资项目的评价。而决策人员面对复杂系统更适合以区间数给出评价。本文提出风险投资的3个评价指标,运用粒子群算法集结区间数信息,构建群决策全局最优偏好矩阵,采用可能度矩阵和排序向量法确定次序。最后的应用研究结果表明,该方法具有一定的可行性和科学性,有利于风险投资项目评价的发展。     

The Role of Stock Size and Trading Intensity in the Magnitude of the "Interval Effect" in Beta Estimation: Empirical Evidence from the Polish Capital Market

In this paper, we present empirical evidence about the "interval effect" in estimation of beta parameters for stocks listed on the Warsaw Stock Exchange. We analyze models constructed for the returns calculated using intervals of different length—that is, 1, 5, 10, and 21 trading days (corresponding to, roughly, 1 day, 1 week, 2 weeks, and 1 month, respectively). In the cases in which heteroskedasticity was present, we estimated ARCH models. The results indicate that the estimates of betas for the same stock differ considerably when various return intervals are used. We further explore the source of differences in betas for every stock by investigating the relations between them and such factors as stock size and its trading intensity. The empirical results provide evidence that a statistically significant relationship exists between these two characteristics of stocks. This finding has important practical implications for beta estimation in practice.     

Optimal variable sample size and sampling interval ‘mean squared error’ chart

The deployment of statistical process control in the service process is a prominent global phenomenon in recent years. In this paper, we proposed the optimal variable sample size and sampling interval (VSSI) mean square error (MSE) control chart to monitor the difference between the process mean and the target value and the process variation shifts, and its performance is measured by the average time to signal. From data analyses, we found the optimal VSSI MSE chart that performs better than the specific VSSI and the optimal variable sampling interval and the fixed parameters MSE charts. An example was given to illustrate this new proposed approach.     

无约束条件下顾客满意与顾客忠诚关系的研究

顾客满意与顾客忠诚的相关性一直是学术界争论的焦点,近年来国内外学者分别从不同行业、不同约束条件的背景出发,对顾客满意和顾客忠诚关系进行了理论和实证研究,但是对于作用于顾客满意和顾客忠诚关系的影响因素研究较少.本文在剔除资源垄断、法律规定、政治安全、文化差异等约束条件后,对顾客满意与顾客忠诚关系进行了界定,并对二者关系的影响因素及其作用机理进行了分析,以期对企业的顾客关系管理提供一定的借鉴.     

论连续并购与间隔并购样本的差异

在已有对并购的研究中,学者们没有细分连续并购样本和间隔并购样本。他们大多数采取两种方式:一种是把连续并购剔除在外,另一种是把连续并购和间隔并购放在一起,致使我们的并购研究无法突破。本研究选取四大类别熵,即:支持型熵、压力型熵、还原型熵、氧化型熵作为变量,利用参数和非参数检验进行样本的差异检验。最后发现:连续并购和间隔并购有实质性的区别。这给我们今后做并购研究的样本选取提供了有利的支持。     

Estimating and Testing Process Precision with Presence of Gauge Measurement Errors

Process capability indices have been widely used in the manufacturing industry. Those capability indices, quantifying process potential and performance, are important for any successful quality improvement activities and quality program implementation. Because of the simplicity and easy of understanding, the precision index C_p has gained its popularity for measuring process consistency. However, the quality of data on the process characteristics relies very much on the gauge measurement. Conclusions about capability of the process just only based on the single numerical value of the index are not reliable. In this paper, we not only conduct the performance of the index C_p with gauge measurement errors, but also present adjusted confidence interval bounds and critical values for capability testing purpose of C_p with unavoidable measurement errors. Our research would help practitioners to determine whether the factory processes meet the capability requirement, and make more reliable decisions.     

Isotonic estimators of monotone densities and distribution functions: basic facts

We present short proofs of some basic results from isotonic regression theory. A straightforward argument is given to show that the left continuous version of the concave majorant of the empirical distribution function maximizes the likelihood function f↦f (X,)… f (X _n ) within the class of non-increasing densities. Similarly, it is shown that the nonparametric maximum likelihood estimator (NPMLE) of the distribution function of interval censored data has an interpretation in terms of the left derivative of a convex minor ant. Finally, a short proof is given to show that the number of vertices of the concave major ant of the uniform empirical distribution function is asymptotically normal with asymptotic mean and variance both equal to log n .     

Fractional integration and interval prediction

The motivation for fractional integration in terms of low-frequency spectral behavior and long-lag auto-correlation behavior is well known. Using results on the rate of growth of variances of sums of integrated random variables, we provide additional and complementary time-domain motivation for fractional integration in terms of the long-horizon behavior of (1) the variance-time function, and (2) confidence intervals for predictions. The results are illustrated with an empirical application to real interest rate forecasting.     

Public Preferences for Hydrogen Buses: Comparing Interval Data, OLS and Quantile Regression Approaches

We use a quantile regression (QR) approach to analyse contingent valuation estimates of public willingness to pay (WTP) for the air and noise pollution reductions associated with the introduction of hydrogen buses in London. QR results show that variables that were not significant in interval regression or ordinary least squares regression become significant at certain quantiles along the WTP distribution. In addition, the determinants of WTP at the lower tail of the distribution differ from those at the higher end of the distribution. Our findings illustrate the usefulness of quantile regression methods for analysing contingent valuation data, enhancing our understanding of the determinants of willingness to pay.     

总量均衡区间及其对通货膨胀与通货紧缩的"放大"效应

现代市场经济运行中由于供给方调整供给量须耗费调节成本,因而传统分析中的"总量均衡中心点"两侧便分别存在着"低位临界点"与"高位临界点",这两点界定了一个特殊的总量均衡区间.总量均衡区间的存在将对通货膨胀与通货紧缩产生一种特殊的"放大"效应,从而对宏观经济运行与调控产生诸多负面影响.对此须予以充分关注,并采取必要措施加以应对.