A new financial stress index model based on support vector regression and control chart

Financial stress index (FSI) is considered to be an important risk management tool to quantify financial vulnerabilities. This paper proposes a new framework based on a hybrid classifier model that integrates rough set theory (RST), FSI, support vector regression (SVR) and a control chart to identify stressed periods. First, the RST method is applied to select variables. The outputs are used as input data for FSI–SVR computation. Empirical analysis is conducted based on monthly FSI of the Federal Reserve Bank of Saint Louis from January 1992 to June 2011. A comparison study is performed between FSI based on the principal component analysis and FSI–SVR. A control chart based on FSI–SVR and extreme value theory is proposed to identify the extremely stressed periods. Our approach identified different stressed periods including internet bubble, subprime crisis and actual financial stress episodes, along with the calmest periods, agreeing with those given by Federal Reserve System reports.     

Beyond tail median and conditional tail expectation: Extreme risk estimation using tail Lp-optimization

The conditional tail expectation (CTE) is an indicator of tail behavior that takes into account both the frequency and magnitude of a tail event. However, the asymptotic normality of its empirical estimator requires that the underlying distribution possess a finite variance; this can be a strong restriction in actuarial and financial applications. A valuable alternative is the median shortfall (MS), although it only gives information about the frequency of a tail event. We construct a class of tail L^p-medians encompassing the MS and CTE. For p in (1,2), a tail L^p-median depends on both the frequency and magnitude of tail events, and its empirical estimator is, within the range of the data, asymptotically normal under a condition weaker than a finite variance. We extrapolate this estimator and another technique to extreme levels using the heavy-tailed framework. The estimators are showcased on a simulation study and on real fire insurance data.     

虎鲨对温度、pH值的耐受性研究

本文报道了在LRH-250E型培养箱中对平均尾重0.2g和1.2g的虎鲨进行温度耐受性试验,并对均重1.2g的虎鲨做了pH耐受性研究。结果表明:尾重O.2g的虎鲨在驯化温度为20℃时,水温突变引起的致死高温为41℃,致死低温为14℃;尾重1.2g虎鲨在驯化温度为24℃时,水温突变引起的致死高温是42℃,致死低温为14.5℃。尾重1.2g虎鲨能够耐受的pH值其上限是11.51,下限是2.52。     

载体催化元件恒温检测甲烷浓度的研究

基于载体催化元件检测甲烷浓度的基本原理,提出了采用载体催化元件和参比元件组成惠斯登测量电桥,运用温度自动控制系统达到恒定甲烷无焰燃烧温度,实现甲烷浓度的测量。扩展了采用载体催化元件测量甲烷浓度时的测量范围,减轻了催化剂的高温烧结和挥发现象,延长了载体催化元件的使用寿命。并建立了相应的温度自动控制和甲烷浓度测量的数学模型。     

测定小惯性热电偶时间常数新法

研究了用电加热法解决用于动态气流温度测量的小惯性热电偶时间常数的实验测定问题。提出采取在稳定气流场中用电加热热电偶然后迅速切断电源的方法 ,获取较为理想的负温度阶跃 ,进而由热电偶的阶跃响应曲线求得时间常数。设计了相应的设备 ,并进行了实验测定 ,获得了较好的结果。     

浅谈我国古代文艺作品中的影射技法

影射 ,作为一种文学技巧 ,最先出现在《诗经》 ,日后由于意识形态变化的原因 ,并在儒家文学观的指引下 ,逐渐推广到辞赋、散文、小说、词曲和戏剧所有文学领域 ,表现形式也由单一的比喻象征发展到多种类型 ,形成姿态横生、形式大备、羽翼丰满的艺术手段     

论艺术设计专业表现技法的两种形式

艺术设计专业中的表现技法有多种。此文论述了素描点绘形式和色彩喷绘形式的表现技法。如果学生在实践中掌握了这门主要专业课程,就会为今后的电脑图形设计打下坚实的基础。     

李白与杜甫面面观

围绕李白与杜甫的生平行事及其诗歌创作,从八个层面进行对比论述,所谓“以诗证史,有裨于知人论世”。文中既综合了当代的研究成果,也提出了一些新的见解。     

治理黄土高原必须抓住关键突破口

黄土高原是我国独特的地理区域,其水土流失严重,生态环境恶化,经济落后,问题很多,如何治理黄土高原一直是个难题。若能抓住关键突破口,如种树种草改善生态环境,防止水土流失,建设基本农田,解决粮食问题,开展多种经营,增加经济收入等,进行综合治理和开发,问题便将迎刃而解。     

硫酸盐镀锌光亮剂高温载体的合成及性能研究

以正交实验法对硫酸盐镀锌光亮剂高温载体GZL-02的合成工艺条件进行了优化研究,并对其表面化学性能和电镀性能进行了测定.最佳合成工艺条件为,聚醚∶顺酐=1∶1.05(摩尔比),酯化温度75℃,时间2h.最终产物得率超过97%.