我国统计数据质量的评估方法研究————————趋势模拟评估法及其应用

 本文采用组合模型的形式对时间序列数据的变化特点建模，在模型通过各种检验、具有良好统计预测功能的基础上，从检验异常值的角度来分析预测值与实际值之间差异的程度，找出离群数据，利用数理统计中检验实验观测数据异常值的方法，对离群数据的误差进行统计上的显著检验，从而评估统计数据的质量。文章以我国国内生产总值（GDP）为研究对象，选取我国1978-2003年间的GDP作为样本，运用趋势模拟评估法来评估我国2004年国内生产总值的准确性。对我国经济指标的时间序列数据进行了实证分析。     

电信运营商投资效益仿真研究——基于系统动力学视角

针对目前电信运营商投资效益分析方法单一的现状,依据电信运营商投资效益非线性、动态性等特征,运用系统动力学方法构建了电信运营商投资效益仿真模型,对电信运营商投资效益影响因素进行了仿真分析。结果表明网络设备延迟投入、综合造价等对投资效益影响较大,在此基础上,给出了电信运营商在针对投入产出水平和提升效益方面的建议。     

非对称基坑开挖监测位移下数值对比分析

以南京市青奥轴线地下交通工程主隧道基坑非对称开挖水平位移监测数据为依据,对水平位移监测值与ABAQUS数值模拟值进行对比分析。得出结论:墙体水平位移首先是悬臂开挖的墙顶向外发生三角形分布的位移,然后随着支撑的架设,墙体发生转动,数值模拟值与实际监测值基本符合;在开挖面附近的土压力,随着墙体高度的增加而增大;在支撑以上部分,模拟值要小于计算值,而在开挖面以下部分,则模拟值大于计算值;随着悬臂段开挖深度的增加,悬臂段最大土压力值也在逐渐增加,墙底土压力值在逐渐减小。     

除尘器区低温省煤器烟道数值模拟

为实现除尘器区低温省煤器的节能改造,基于FLUENT6.3软件,对除尘器区低温省煤器烟道的流场进行数值模拟研究。研究结果表明:除尘器前烟道内流场严重不均,转弯处有明显的高速区与漩涡区,局部速度高达32 m/s;加装低温省煤器后,两低温省煤器内流场不均,最大速度偏差系数达79.3%,严重影响低温省煤器的换热效果,同时会磨损、冲刷低温省煤器管路,危及低温省煤器的安全;除尘器入口处出现大面积的低速区域,导致进入除尘器后流场紊乱、除尘器电耗高、除尘效率低等现象,除尘器前烟道内整流消涡可以根治除尘器工作效率的问题。     

散热器安装模式对采暖效果的影响

为了探究冷凝壁挂炉散热器的安装模式对采暖效果的影响,建立了散热器对流采暖的数学模型,利用CFD软件 SC/Tetra,采用湍流模型和稳态分析法,模拟了在实际工况下,不同安装模式的散热器达到稳态时温度场和速度场的分 布,并对数值模拟结果进行分析。结果表明：总功率相同的条件下,双散热器相比单个散热器,温度场和速度场更加均匀 平稳,舒适性较好;同侧安装方式比对称安装及对角线方向安装方式也更具有优越性,该研究为今后的工程应用提供理 论依据。     

我国居民家庭生命周期消费储蓄行为动态模拟研究

本文建立了家庭生命周期消费储蓄优化模拟模型,并利用该模型对我国居民家庭生命周期阶段各类家庭的消费储蓄行为进行了模拟研究,比较分析了家庭生育决策、教育决策和收入转移决策变化对家庭消费储蓄行为的影响以及利率变动和信贷约束的影响。模拟结果显示,信贷约束对家庭消费路径有着重要影响,约束了家庭在新生阶段和中间阶段的消费水平;教育费用的提高和教育投资实现的不确定性风险提高了家庭的教育储蓄水平;生育数的降低、教育投资机会的短缺和代际关系的松散化趋势提高了家庭的养老储蓄水平。利率的提高使生命周期前期的家庭消费下降,使生命周期后期的家庭消费提高。提高利率政策的消费传导效应,可以通过提高受教育程度和增加消费信贷来实现。     

Goodness-of-fit test for exponentiality based on spacings for general progressive Type-II censored data

There have been numerous tests proposed to determine whether or not the exponential model is suitable for a given data set. In this article, we propose a new test statistic based on spacings to test whether the general progressive Type-II censored samples are from exponential distribution. The null distribution of the test statistic is discussed and it could be approximated by the standard normal distribution. Meanwhile, we propose an approximate method for calculating the expectation and variance of samples under null hypothesis and corresponding power function is also given. Then, a simulation study is conducted. We calculate the approximation of the power based on normality and compare the results with those obtained by Monte Carlo simulation under different alternatives with distinct types of hazard function. Results of simulation study disclose that the power properties of this statistic by using Monte Carlo simulation are better for the alternatives with monotone increasing hazard function, and otherwise, normal approximation simulation results are relatively better. Finally, two illustrative examples are presented.     

Construction Safety Risk Modeling and Simulation

By building on a genetic‐inspired attribute‐based conceptual framework for safety risk analysis, we propose a novel approach to define, model, and simulate univariate and bivariate construction safety risk at the situational level. Our fully data‐driven techniques provide construction practitioners and academicians with an easy and automated way of getting valuable empirical insights from attribute‐based data extracted from unstructured textual injury reports. By applying our methodology on a data set of 814 injury reports, we first show the frequency‐magnitude distribution of construction safety risk to be very similar to that of many natural phenomena such as precipitation or earthquakes. Motivated by this observation, and drawing on state‐of‐the‐art techniques in hydroclimatology and insurance, we then introduce univariate and bivariate nonparametric stochastic safety risk generators based on kernel density estimators and copulas. These generators enable the user to produce large numbers of synthetic safety risk values faithful to the original data, allowing safety‐related decision making under uncertainty to be grounded on extensive empirical evidence. One of the implications of our study is that like natural phenomena, construction safety may benefit from being studied quantitatively by leveraging empirical data rather than strictly being approached through a managerial perspective using subjective data, which is the current industry standard. Finally, a side but interesting finding is that in our data set, attributes related to high energy levels (e.g., machinery, hazardous substance) and to human error (e.g., improper security of tools) emerge as strong risk shapers.     

‘Media Events’ reconsidered: from ritual theory to simulation and performativity

This paper re-examines the long-established notion of ‘media events’ by contrasting and critically appraising three distinct approaches to the question of media events. These are: ritual theory associated with Daniel Dayan and Elihu Katz, secondly, Jean Baudrillard’s approach rooted in his notions of simulation and ‘non-events’ and, finally, the more recent performative approaches to media and mediation. I take Sarah Kember and Joanna Zylinska’s reading of media events presented in Life After New Media (2012) as exemplary of the performative approach. An argument is made that the accounts of media events offered by performative approaches add very little, and, indeed, lack the critical insightfulness of the earlier approaches. Both ritual theory and Baudrillard’s thought are briefly reappraised and, against Nick Couldry, I try to show that these accounts are not characterised by binary and reductive thinking. The major misunderstandings concern the nature of the sacred and profane dualism and the further dualisms developed in Baudrillard’s thought, particularly the figures of implosion and reversibility. Finally, Baudrillard’s position on technology is addressed and the paper concludes with the suggestion that his account is not solely negative, since technological developments are not only at the mercy of ironic reversals they may also enable new rituals of disappearance.