全断面隧道掘进机工作参数匹配规律的挖掘与利用

为提高隧道掘进机工作效能和利用率，以采集的秦岭隧道工作数据为对象，分析研究了不同掘进状况下工作参数间的匹配规律，对比分析了各类掘进状况下的切削比能，获得了掘进机正常掘进状况下的FPI与切割系数C的制约方程，得到了软、硬岩条降下的推进力、扭矩需求方程，并且从统计角度获得了切割系数的概率密度分布函数。所获得的相关规律以及处理方法，为掘进状况的预测和掘进参数的优化提供了一定的知识和技术支持，对于掘进机的性能评价和掘进机设计部具有重要的参考价值。     

Nonlinear regression models for heterogeneous data with massive outliers

The income or expenditure-related data sets are often nonlinear, heteroscedastic, skewed even after the transformation, and contain numerous outliers. We propose a class of robust nonlinear models that treat outlying observations effectively without removing them. For this purpose, case-specific parameters and a related penalty are employed to detect and modify the outliers systematically. We show how the existing nonlinear models such as smoothing splines and generalized additive models can be robustified by the case-specific parameters. Next, we extend the proposed methods to the heterogeneous models by incorporating unequal weights. The details of estimating the weights are provided. Two real data sets and simulated data sets show the potential of the proposed methods when the nature of the data is nonlinear with outlying observations.     

融合特征情感和产品参数的客户感知偏好模型

在线评论作为一种公开、可获取的信息资源，蕴含了关于产品质量的各种有价值的信息，对这些信息的分析与挖掘有助于企业了解客户的需求和偏好。目前，基于在线评论的客户偏好模型考虑了特征观点和评论数量，忽视了产品参数对消费者购买决策的影响。因此，本文提出了一种融合特征情感和产品参数的客户感知偏好模型。首先，利用在线评论提取客户讨论的产品特征，并识别产品特征的情感极性，从而进一步计算特征正负面情感得分，生成产品的特征情感。然后，结合企业定义的产品参数，构建特征情感和产品参数融合作用对产品销量影响的计量经济模型，分析客户对产品的感知偏好。最后，为验证模型的有效性，获取了汽车之家网站的39款汽车产品（SUV车型）的评论文本，并持续8个月的销量跟踪。研究结果显示本文提出的模型比信息增益和TF-IDF方法能够更加准确地获取客户的感知偏好。此外，研究结果解释了特征情感和产品参数与产品销量的关联关系，为企业的市场营销和产品设计决策提供了理论基础。     

Bayesian robustness in meta‐analysis for studies with zero responses

Statistical meta‐analysis is mostly carried out with the help of the random effect normal model, including the case of discrete random variables. We argue that the normal approximation is not always able to adequately capture the underlying uncertainty of the original discrete data. Furthermore, when we examine the influence of the prior distributions considered, in the presence of rare events, the results from this approximation can be very poor. In order to assess the robustness of the quantities of interest in meta‐analysis with respect to the choice of priors, this paper proposes an alternative Bayesian model for binomial random variables with several zero responses. Particular attention is paid to the coherence between the prior distributions of the study model parameters and the meta‐parameter. Thus, our method introduces a simple way to examine the sensitivity of these quantities to the structure dependence selected for study. For illustrative purposes, an example with real data is analysed, using the proposed Bayesian meta‐analysis model for binomial sparse data. Copyright © 2016 John Wiley & Sons, Ltd.     

基于正交试验法的电流线圈架塑件工艺参数优化设计

为改善塑件的成型质量,采用正交试验法,选择注射时间、熔体温度、保压压力、保压时间以及冷却时间等5个工 艺参数作为控制因素。对各因素分别赋以4个水平,以塑件的翘曲量作为质量指标,建立正交试验表L16(45)。运用模 拟流动分析软件,对不同工艺条件下的塑件成型过程进行模拟分析,得到各翘曲值。对塑件翘曲产生的原因进行分析,分 析表明：保压时间和保压压力为影响塑件翘曲量最大的2个因素,通过改变这2个因素值可有效改善塑件的翘曲状况。     

Reference database of hematological parameters for growing and aging rats

The normal hematological values in various phases of the rat life provide a valuable guide to researchers and could be useful for experimental works. However, database information available on the literature are incomplete. Aim: This study aimed to present normal hematological parameters of young and aged rats.

Methods: Male and female rats were distributed into seven experimental groups with 1, 2, 3, 6, 12, 18, and 24 months of age. Blood samples taken from the tails were analyzed. Normal hematological values were determined for each age group.

Results: Rats showed a progressive weight gain with advancing age, predominantly after 3 months of life. With advancing age, differences were found on hematological parameters: some of them showed a progressive rise with age and others did not. Hemoglobin levels and hematocrit did not change while the number of circulating red blood cells suffered slight increase.

Conclusion: The present study determined the normal values for absolute and relative hematological parameters in Wistar rats from 2 to 24 months for male and female rats. The results can be used in studies of effects of aging, feeding, and medications on growing and aging rats.     

ESTIMATION, PREDICTION AND INFERENCE FOR THE LASSO RANDOM EFFECTS MODEL

The least absolute shrinkage and selection operator (LASSO) can be formulated as a random effects model with an associated variance parameter that can be estimated with other components of variance. In this paper, estimation of the variance parameters is performed by means of an approximation to the marginal likelihood of the observed outcomes. The approximation is based on an alternative but equivalent formulation of the LASSO random effects model. Predictions can be made using point summaries of the predictive distribution of the random effects given the data with the parameters set to their estimated values. The standard LASSO method uses the mode of this distribution as the predictor. It is not the only choice, and a number of other possibilities are defined and empirically assessed in this article. The predictive mode is competitive with the predictive mean (best predictor), but no single predictor performs best across in all situations. Inference for the LASSO random effects is performed using predictive probability statements, which are more appropriate under the random effects formulation than tests of hypothesis.     

Departure from independence and stationarity in a handball match

This paper analyses direct and indirect forms of dependence in the probability of scoring in a handball match, taking into account the mutual influence of both playing teams. Non-identical distribution (i.d.) and non-stationarity, which are commonly observed in sport games, are studied through the specification of time-varying parameters.

The model accounts for the binary character of the dependent variable, and for unobserved heterogeneity. The parameter dynamics is specified by a first-order auto-regressive process.

Data from the Handball World Championships 2001–2005 show that the dynamics of handball violate both independence and i.d., in some cases having a non-stationary behaviour.     

Archimedean copulae for risk measurement

In this paper some Archimedean copula functions for bivariate financial returns are studied. The choice of this family is due to their ability to capture the tail dependence, which is an association measure we can detect in many bivariate financial time-series. A time-varying version of these copulae is also investigated. Finally, the Value-at-Risk is computed and its performance is compared across different copula specifications.