A robust finite difference scheme for pricing American put options with Singularity-Separating method

In this paper we present a stable numerical method for the linear complementary problem arising from American put option pricing. The numerical method is based on a hybrid finite difference spatial discretization on a piecewise uniform mesh and an implicit time stepping technique. The scheme is stable for arbitrary volatility and arbitrary interest rate. We apply some tricks to derive the error estimates for the direct application of finite difference method to the linear complementary problem. We use the Singularity-Separating method to remove the singularity of the non-smooth payoff function. It is proved that the scheme is second-order convergent with respect to the spatial variable. Numerical results support the theoretical results.     

全矩阵Γ-环的von Neumann正则性

摘要本文讨论Γ-环R上的全矩阵Γ-环R.的von Neumann正则性。主要证明以下结果: 1 设R是Γ-环,I是R的理想,那么M(I_n)=(M(I))_n 2 设R是Γ-环,全矩阵Γ-环R_n为von Neumann正则的充要条件是R为von Nenmann正则的。 3 设R是Γ-环,R的理想的集合记为H,R_n的理想的集合记为K,则ψ:I→I_n是H到K的保序单射,且R的von Neumann正则理想与R_n的vonNeumann正则理想是一一对应的。     

关于范畴中态射集偏序的刻划问题

本文讨论范畴中态射集偏序的刻划问题，给出了态射偏序的一致刻划。     

Damage analysis by boundary element method

The response of cracked bodies subjected to loading was investigated by the boundary element method in this paper. The two-law elastic-cohesive-softening model was used for crack propagation analysis. The interface conditions for uncracked, craze, open crack, adhesive crack and slid crack parts were discussed and the corresponding incremental iteration algorithm was given. A simplified damage propagation model was presented. The technique has been applied to some specific examples which give the evidence that the method is satisfactory and efficient.     

Degradation of Phenol in Aqueous Solutions by Gas–Liquid Gliding Arc Discharges

The efficiency of a gliding arc reactor designed with the aim to degrade aqueous phenol solutions is studied as a function of supply voltage, electrode gap distance, and gas–liquid flow properties. This efficiency, which steeply increases when increasing the supply voltage, can reach 96% when the minimum electrode distance is fixed at 3 mm. Experiments show that phenol degradation efficiency also depends on solution pH, Fe²⁺ addition, gas nature and gas flow rate. Furthermore, degradation pathways of phenol in aqueous solutions are proposed.     

应力场下聚丙烯熔体的结晶与硬弹性的形成

应力场下聚丙烯熔体的结晶与硬弹性的形成胡继文＊孙友德许耀光岑美柱（中国科学院广州化学研究所广州５１０６５０）关键词聚丙烯，硬弹性，应力导致结晶１９９６－１２－２０收稿，１９９７－０５－２０修回研究表明，具有硬弹性的聚合物形态的获得最关键的因素是熔纺时...