Local composite quantile regression estimation of time-varying parameter vector for multidimensional time-inhomogeneous diffusion models

This paper is dedicated to the study of the composite quantile regression (CQR) estimations of time-varying parameter vectors for multidimensional diffusion models. Based on the local linear fitting for parameter vectors, we propose the local linear CQR estimations of the drift parameter vectors, and verify their asymptotic biases, asymptotic variances and asymptotic normality. Moreover, we discuss the asymptotic relative efficiency (ARE) of the local linear CQR estimations with respect to the local linear least-squares estimations. We obtain that the local estimations that we proposed are much more efficient than the local linear least-squares estimations. Simulation studies are constructed to show the performance of the estimations proposed.     

阻沙率在沙漠公路高大沙丘段防沙体系设计中的应用

在工程防沙设计中，阻沙率和输沙强度均是确定防护类型及其宽度的重要指标。从工程实际出发，结合典型地形特征，运用实测的阻沙率指标，优化沙漠公路高大沙丘段防沙体系的设计，用理论指导实践的同时，并在实践施工中加以较好地运用，从实践效果上，以阻沙率这一风沙物理指标为依据，确定高大沙丘段的防沙设计参数，是符合实际和可行的方法。     

基于模仿创新的产品设计

在当前我国产品设计相对薄弱,企业资金投入不足的情形下,较难自主创新,模仿创新成为产品设计跨越式发展的必经之路。模仿创新相较率先创新具有后发优势,反而能设计出占据市场主导地位和最具经济效益的产品。但模仿创新不是恶劣的伪造,重点在于借鉴改造,从而形成自身风格。     

材料发展对建筑装饰设计影响的研究

由材料发展引发的一系列关于建筑装饰设计创新的概念,其主要的目的就是更好将建筑装饰设计与材料运用结合起来。只有通过建筑装饰材料的更新与发展,才能达到将建筑装饰设计艺术、技术结合起来快速发展的目标。从建筑装饰材料发展的历史入手,分析建筑装饰材料使用现状,结合材料特性、绿色环保、智能材料、节能材料、低碳等角度对未来材料的可能性发展方向及其对建筑装饰设计的影响进行探讨,总结归纳材料发展对建筑装饰设计影响的一般性规律,促进建筑装饰设计文化的发展与繁荣,营造宜居人居环境。     

An integrated model based on statistical process control and maintenance for two-stage dependent processes

The close relationship between quality and maintenance of manufacturing systems has contributed to the development of integrated models which use the concept of statistical process control (SPC) and maintenance. This article demonstrates the integration of the Shewhart individual-residual (Z_X ? Z_e) joint control chart and maintenance for two-stage dependent processes by jointly optimizing their policies to minimize the expected total costs associated with quality, maintenance and inspection. To evaluate the effectiveness of the proposed model, two stand-alone models—a maintenance model and an SPC model—are proposed. Then a numerical example is given to illustrate the application of the proposed integrated model. The results show that the integrated model outperforms the two stand-alone models with regard to the expected cost per unit time. Finally, a sensitivity analysis is conducted to develop insights into time parameters and cost parameters that influence the integration efforts.     

企业内部控制的思考

现代企业从事的社会化大生产,具有分工精细、协作广泛的特点。日新月异的科学技术、加速发展的全球一体化进程,使得企业面临着错综复杂的政治、经济、文化、社会等内部环境。因此,企业要正确定位,优化设计,实施与持续改进绩效考评,建立资源计划系统以应对不断变化的形势。     

Bias correction for parameter estimates of spatial point process models

When a spatial point process model is fitted to spatial point pattern data using standard software, the parameter estimates are typically biased. Contrary to folklore, the bias does not reflect weaknesses of the underlying mathematical methods, but is mainly due to the effects of discretization of the spatial domain. We investigate two approaches to correcting the bias: a Newton–Raphson-type correction and Richardson extrapolation. In simulation experiments, Richardson extrapolation performs best.     

Economic and economic statistical designs for three-level control charts

In some situations, an appropriate quality measure uses three or more discrete levels to classify a product characteristic. For these situations, some control charts have been developed based on statistical criteria regardless of economic considerations. In this paper, we develop economic and economic statistical designs (ESD) for 3-level control charts. We apply the cost model proposed by Costa and Rahim.[Economic design of X charts with variable parameters: the Markov chain approach, J Appl Stat 28 (2001), 875–885] Furthermore, we assume that the length of time that the process remains in control is exponentially distributed which allows us to apply the Markov chain approach for developing the cost model. We apply a genetic algorithm to determine the optimal values of model parameters by minimizing the cost function. A numerical example is provided to illustrate the performance of the proposed models and to compare the cost of the pure economic and ESD for three-level control charts. A sensitivity analysis is also conducted in this numerical example.     

闻一多书籍装帧封面的视觉要素分析

闻一多是现代一位出色的装帧家,装帧作品虽然不多,但精品不少,尤以封面设计作品较为突出。闻一多的书籍封面设计,在视觉要素运用上,文字新颖多变,图形表现兼容并蓄,色彩运用简洁鲜明,为我国现代书籍装帧艺术的发展做出了贡献。