大倾角超长综放工作面放顶煤工艺浅析

结合放顶煤工艺在公乌素煤业大倾角超长工作面的应用现状,分析了放顶煤工艺参数的选择、方案的确定、工序的安排及取得的高产高效成果等,提出了放顶煤工艺在公乌素煤业16#煤层中应用时为进一步提高煤炭资源回收率而需改进的工作。     

电参数检测装置的研究

随着我国电力市场的逐步建立和完善,电力系统越来越复杂,电力检测装置在电力管理系统占有举足轻重的地位,因此,针对不同领域的电力系统,投入多功能的电力检测装置的开发是明智之举,此装置的研制成功可使电压、电流、功率、功率因数和频率等电力参数进行实时检测,对于实现电网安全、高效和经济的运行具有十分重要的意义。本文将采用高精度三相电量测量专用芯片,对电力系统中的重要参数如何检测进行简要分析。     

基于遗传算法的模糊控制器参数优化

针对非线性量化因子模糊控制器的参数对系统性能影响和参数间的相互制约,提出了一种基于遗传算法的参数整定与优化方法,并进行了仿真研究。仿真结果表明通过该方法寻优的系统具有更好的响应速度和控制精度；当对象结构或参数发生变化时,非线性量化因子模糊控制器可以重新整定参数,以保持良好的控制效果,具有很强的鲁棒性。     

Binomial option pricing with stochastic parameters: A beta distribution approach

This research extends the binomial option-pricing model of Cox, Ross, and Rubinstein (1979) and Rendleman and Barter (1979) to the case where the up and down percentage changes of stock prices are stochastic. Assuming stochastic parameters in the discrete-time binomial option pricing is analogous to assuming stochastic volatility in the continuous-time option pricing. By assuming that the up and down parameters are independent random variables following beta distributions, we are able to derive a closed-form solution to this stochastic discrete-time option pricing. We also derive an upper and a lower bounds of the option price.     

Analysis of Instantaneous and Early Failures in Weibull Distribution

There are many situations in life testing experiment where an item fail instantaneously and hence the observed lifetime is reported as zero. The items that fail prematurely are called early failures. We propose a modified Weibull distribution as a suitable model to represent such situations by mixture of a singular distribution at zero and a two parameter Weibull distribution. We obtain the maximum likelihood estimates of the parameters and their asymptotic distributions. The methods are illustrated on drying of woods under different experiments and schedules reported by Vanmann (Research report, 1991:2).     

油水井套变地层岩石力学参数反演分析

以套管变形测井资料为基础,利用APDL编制有限元优化模块反演套变围岩力学参数,即可确定套变地层缺失的力学参数,又克服目前套管变形分析多是基于弹性模型,不能进行塑性变形分析的问题。同时在岩石力学参数反演程序中引入莫尔―库伦破坏准则,确定岩层内摩擦角与黏聚力、最大水平主应力和最小水平主应力之间的关系,使反演解具有唯一性。该方法为套变围岩岩石力学参数的确定提供了新方法,并较传统反演方法更为简捷高效。     

The anthropocenic imaginary: political ecologies of tourism in a geological epoch

Abstract

The Anthropocene is fundamentally a social imaginary that is both shaped by and is reshaping tourism practice. In this article, we enroll the concept of the anthropocenic imaginary to describe how the Anthropocene is symbolically and materially produced as well as the ways in which it draws on the historical separation of Humanity and Nature. As the structural roots from which the anthropocenic imaginary has grown, this binary co-produces new and old forms of political and ecological inclusion and exclusion. We demonstrate how core themes in tourism studies have fertilized the seeds from which the theoretical branches of post-humanist, capitalist and ecological imaginaries in tourism have taken shape. These anthropocenic imaginaries, we argue, are appropriated in market-based solutions to environmental degradation that emanate from neoliberal contexts internal to the problem. Thus, we question the reconciliation of capitalist accumulation and environmental limits in sustainable tourism. This article and the papers in this issue push forward emerging approaches in the political ecology of tourism that recognize the Anthropocene as both a geological epoch and conceptual regime. In doing so, the issue contributes to emerging conversations on the relationship between politics, ecology and tourism in the so-called recent age of man.     

上市公司财务参数与其股价波动性关系探究

本文探究了上市公司年度股价波动性与其上一年公开财务指标的相关关系。公开财务指标主要包括六项,从不同维度反映了公司规模、资本结构、偿债能力、盈利状况、管理状况和股东情况。通过分析结果发现,若干财务指标与上市公司的股价波动性都有显著的相关关系,大部分符合预期及常识。有一些财务指标与上市公司的股价波动性长时期内表现出稳定、显著的关系。文中尝试探讨了造成这种相关性的因素。     

机构投资者对证券市场价格波动性的影响——基于Topview数据的实证研究

本文在完整的市场结构数据基础上,研究了市场波动性与机构投资者之间的相互关系。在研究数据方面,我们采用了深度、高频的Topview数据,既避免了前人在研究数据方面的以偏概全,也让我们可以采用更为先进、稳健的实证方法。我们设定了恰当的波动性度量指标,运用了稳健的因果推断方法。并用脉冲响应和方差分解的方法细腻刻画两者之间的相互关系。本文的主要结论是:机构投资者持股比率的波动对上证指数波动有显著的影响,是导致上证指数波动最为主要的原因,法人投资者和个人大户投资者持股比率的变动对上证指数的波动几乎没有影响,机构投资者持股比率波动还会向法人投资者、个人大户投资者持股比率溢出,这些表明在上海证券市场上机构投资者是市场波动的主要来源和主要原因。机构投资者的多元化、坚决推进市场的规范化改革应当成为未来政策关注的重点。     

浅述岩体力学参数监测在隧道施工中的重要性

采用新奥法进行隧道工程施工时,设计单位只能根据监控单位和施工单位反馈的监控数据和隧道开挖揭露情况对设计的合理性进行宏观判断,隧道设计时应把力学计算和实际背景岩体力学参数相结合,才能更科学、经济的按照新奥法的理念完成隧道工程的设计、施工。