公司所得税边际税率的模拟估值研究

以筛选后的377家上市公司为样本,利用随机游走模型计算了2005-2009年我国上市公司的边际税率,并对不同性质、规模、行业企业的边际税率分布及变化情况进行了分析.得出影响我国企业边际税率的主要因素是企业所适用的比例税率、享受的相关税收优惠政策及企业的经营状况.

超主权国际货币运行的实证研究——模拟估值、汇率体系与绩效检验

2008年的国际金融危机暴露出当前国际货币体系的严重缺陷,关于超主权国际货币的讨论成为学术界的热点。超主权国际货币以美元、欧元、日元、英镑和人民币等五种货币为基础,每种货币的权重取决其所属经济体的国内生产总值、国际储备和对外贸易总额,并采用加权平均计算的方法构建。通过对2006—2010年间超主权国际货币的模拟运算及计量分析表明,超主权国际货币体系具有以下三点优势:(1),相对于以美元为核心的国际货币体系,超主权国际货币体系具有更稳定的汇率体系,即各种主要货币对世元汇率的变异系数与汇率偏离度更小;(2),在超主权国际货币体系下,外汇衍生品的交易量会下降,从而导致因外汇交易所付出的佣金支付金额减少,即国际经济活动的交易成本会降低;(3),在超主权国际货币体系下,以石油为代表的大宗商品的价格波动会减缓,从而减小了世界经济发展的不确定性。

中国上市公司企业所得税边际税率的实证研究

基于中国财税法规与资本市场现状,采用5种不同边际税率估算方法对中国1859家上市公司2007—2014年边际税率进行估算。针对不同年度、行业的边际税率分布及变化情况进行分析,得出影响中国企业边际税率的主要因素,为国家企业所得税税收优惠政策的制定提供更科学的视角。同时通过对比分析,找出理论最佳模拟边际税率估值法的简易替代估值计算方法,结论对中国边际税率估值、计算和研究有着重要意义。

Parameter identification and pressure control of dynamic system in shield tunneling using least squares method

An estimation approach using least squares method was presented for identificationof model parameters of pressure control in shield tunneling.The state equation ofthe pressure control system for shield tunneling was analytically derived based on themass equilibrium principle that the entry mass of the pressure chamber from cutting headwas equal to excluding mass from the screw conveyor.The randomly observed noise wasnumerically simulated and mixed to simulated observation values of system responses.The numerical simulation shows that the state equation of the pressure control system forshield tunneling is reasonable and the proposed estimation approach is effective even ifthe random observation noise exists.The robustness of the controlling procedure is validatedby numerical simulation results.

Fatigue Life Assessment of Top Tensioned Risers Under Vortex-Induced Vibrations

The fatigue life of top tensioned risers under vortex-induced vibrations (VIVs) with consideration of the effect of internal flowing fluid on the riser is analyzed in the time domain.The long-term stress histories of the riser under VIVs are calculated and the mean stresses,the number of stress cycles and amplitudes are determined by the rainflow counting method.The Palmgren-Miner rule for cumulative damage theory with a specified S-N curve is used to estimate the fatigue life of the riser.The corresponding numerical programs numerical simulation of vortex-induced vibrations (NSVIV) which can be used to calculate the VIV response and fatigue life of the riser are compiled.Finally the influences of the riser's parameters such as flexural rigidity,top tension and internal flow velocity on the fatigue life of the riser are analyzed in detail and some conclusions are drawn.

Building Vulnerability Evaluation in Landslide Deformation Phase

Building vulnerability evaluation is important in the risk assessment on earthquake and flood hazards. But for landslide hazard, it is also a very important part for the people in buildings. Most discussions or researches about building vulnerability are for landslide failure, few for landslide in deformation phase. For this objective, this paper discussed about building vulnerability evaluation using Zhaoshuling landslide as an example Zhaoshuling landslide named located in the Three Gorges Reservoir Area, China. After a field survey on the geological condition of landslide, detailed field investigation on the buildings' location and structure is carried out. To get landslide surface deformation, numerical simulation method is used under the combining condition of water fluctuation and rainfall. Then building deformation and probable damage degree is analyzed according to landslide surface deformation and the relative theory in mining. Based on the national standard building damage classification system, the vulnerability of all the buildings on the landslide is semi-quantitatively evaluated.

An improved method to assess the required strength of cemented backfill in underground stopes with an open face

Backfill is increasingly used in underground mines to reduce the surface impact from the wastes produced by the mining operations. But the main objectives of backfilling are to improve ground stability and reduce ore dilution. To this end, the backfill in a stope must possess a minimum strength to remain self-standing during mining of an adjacent stope. This required strength is often estimated using a solution proposed by Mitchell and co-workers, which was based on a limit equilibrium analysis of a wedge exposed by the open face. In this paper, three dimensional numerical simulations have been performed to assess the behavior of the wedge model. A new limit equilibrium solution is proposed, based on the backfill displacements obtained from the simulations. Comparisons are made between the proposed solution and experimental and numerical modeling results. Compared with the previous solution, a better agreement is obtained between the new solution and experimental results for the required cohesion and factor of safety. For large scale(field) conditions, the results also show that the required strength obtained from the proposed solution corresponds quite well to the simulated backfill response.

An Investigation on Low Frequency Fatigue Damage of Mooring Lines Applied in a Semi-Submersible Platform

Assessing the fatigue life of mooring systems is important for deep water structures. In this paper, a comprehensive fatigue analysis is conducted on the mooring lines applied in a semi-submersible platform with special focus on the low frequency(LF) fatigue damage. Several influential factors, including water depth, wave spectral parameters, and riser system, are considered. Numerical simulation of a semi-submersible platform with the mooring/riser system is executed under different conditions, and the fatigue damage of mooring lines is assessed by using the time domain analysis method as a benchmark. The effects of these factors on the mooring line tension and the fatigue damage are investigated and discussed in detail. Research results indicate that the LF fatigue damage only accounts for a very small portion of the total damage, although the LF components dominate the global motion response and the mooring line tension of the semi-submersible platform. However, it is demonstrated that the LF fatigue damage is clearly affected by the influential factors. The increase in water depth and spectral peak periods, and the existence of risers can weaken the contribution of the LF components to the mooring line fatigue damage, while the fatigue damage due to the LF components increases with the increase of significant wave height.

Asymptotic Formulas for Thermography Based Recovery of Anomalies

We start from a realistic half space then use to develop a mathematical asymptotic model for thermal imaging, which we analysis well suited for the design of reconstruction algorithms. We seek to reconstruct thermal anomalies only through their rough features. With this way our proposed algorithms are stable against measurement noise and geometry perturbations. Based on rigorous asymptotic estimates, we first obtain an approximation for the temperature profile which we then use to design noniterative detection algorithms. We show on numerical simulations evidence that they are accurate and robust. Moreover, we provide a mathematical model for ultrasonic temperature imaging, which is an important technique in cancerous tissue ablation therapy.

Numerical Simulation and Probabilistic Hazard Assessment of Tephra Fallout at Jinlongdingzi Volcano,Longgang Volcanic Field in Jilin Province

Tephra fallout is an important type of hazard caused by explosive volcanic eruption, and numerical simulation has become a fast and effective approach to assess the dispersion and deposition of tephra fallout. According to the improved 2D diffusion model of Suzuki （ 1983）, we edited a tephra diffusion program that can run in the Windows system. Based on previous data, we simulated the diffusion scope of the Jinlongdingzi volcanic eruption, which is the latest eruption in the Longgang volcanic cluster. The simulated results are in good agreement with the results from measurement in situ, indicating that the model is reliable and the parameters used in the model are suitable. By using wind profiles of ten years, 7, 021 simulations under different wind profiles were carried out, and then probabilistic hazard maps of tephra fallout were constructed for tephra thickness thresholds, lcm and 0.5cm. This study can provide an important scientific basis for volcanic hazard analysis, risk mitigation plans and countermeasures in the Longgang volcanic area.

Tsunami Hazard Assessment in the Alboran Sea for the Western Coast of Algeria

In October 1790, a destructive earthquake occurred near Oran city in the western part of Algeria （MSK, Medvdev-Sponheuer-Kamik macroseismic intensity： X）. It generated a tsunami that inundated the Spanish and North Africa coasts. The regional tectonic includes NW-SE compressional stress in Algeria and NE-SW strike-slip structures in the Alboran basin. In this work, we identified tsunami sources for the Alboran from numerical modeling. The sea bottom displacement is calculated from the Okada equations. The tsunami＇s propagation is simulated with the SWAN code. The identified tsunami source for the 1790 event is a 7.5 magnitude earthquake at the entrance of the Oran harbor, with a pure reverse faulting, probably associated with the Murdjajo fold The tsunami wave height profile that is obtained for the city of Oran showed an initial withdrawal of the sea that was followed by tsunami waves reaching 2 meters in height. The results obtained in Spain agree with the observations reported in the literature. Finally, the simulations led to a better understanding of the interdisciplinary approach to be considered as for tsunami sources in the Alboran. Sedimentary mass-movements should be now included as an additional component in the tsunami hazard assessment for the West Mediterranean. The contribution of sedimentary disturbance due to the series of canyons offshore the western margin could induce water waves higher than 2 meters in Western Algeria.

Sequential Estimate for Generalized Linear Models with Uncertain Number of Effective Variables

For the generalized linear model,the authors propose a sequential sampling procedure based on an adaptive shrinkage estimate of parameter.This method can determine a minimum sample size under which effective variables contributing to the model are identified and estimates of regression parameters achieve the required accuracy.The authors prove that the proposed sequential procedure is asymptotically optimal.Numerical simulation studies show that the proposed method can save a large number of samples compared to the traditional sequential approach.