Monodisperse Crosslinked Microsphere Polymer Particles by Dispersion Copolymerization of Glycidyl Methacrylate and Divinylbenzene

Monodisperse polyglycidyl methacrylate (PGMA) microsphere particles crosslinked with divinylbenzene crosslinker were prepared by single-stage dispersion copolymerization in ethanol medium. 1 wt% of DVB was successfully incorporated due to the costabilizing effect of GMA as a surface-active monomer. This behavior may indicate that the fast formation of stable primary particle leads to monodispersity. The average particle sizes and the particle size distributions increased with the DVB crosslinker concentration. The effects of two different variables (initiator concentration, crosslinker concentration) on the rate of dispersion copolymerization have been investigated. With the initiator concentration, the polymerization procedure mainly depended on the dual natures of general dispersion polymerization, in the crosslinked state. Up to 1 wt% DVB, the particle growth was controlled by the monomer diffusion from the continuous phase into the particle phase.     

基于灰色关联分析的财产保险公司偿付能力的模糊综合评判

为解决财产保险公司的偿付能力的评价问题,建立了基于灰色关联分析的模糊综合评判模型.选取了2003-2005年我国8家财产保险公司的相关数据,用灰色关联分析中的点关联系数求解隶属度得出评判矩阵,用范数灰关联度法确定因素集中各因素的权重,从而对其偿付能力进行模糊综合评判,得出各公司的偿付能力所属的类别.并对评语集中各评语赋予适当的权重,对所研究的8家财产保险公司依据其偿付能力的情况进行了排序.     

跳扩散过程下的保险商偿债率模型研究

本文研究了在有金融困境成本的情况下,带有跳扩散过程的保险商偿债率(SR)模型的问题.利用Girsanov定理进行测度变换的方法以及跳扩散过程下的看涨期权定价公式,获得了保险商终期收益的现值的结果.推广了不带跳扩散过程的保险商偿债率模型的结果.     

Binary Interaction Parameters,Ternary Systems: Realistic Modeling of Liquid/Liquid Phase Separation

The phase behavior of ternary systems (either a polymer solution in a mixed solvent or a polymer blend in a single solvent) was modeled theoretically. The modeling considers two specific features of polymers explicitly: chain connectivity and the ability to respond to changes in the molecular environment by conformational reorientation. Previously, this approach has been applied to polymer solutions in single solvents. Here it is generalized and the number of parameters is reduced to two per binary system. The calculation of the Gibbs energies of the ternary mixtures accounts for the composition dependencies of the binary interaction parameters. The following phenomena are reproduced realistically for polymer solutions in a mixed solvent and for solutions of two polymers in a common solvent: simplicity, co‐solvency, and co‐non‐solvency. The results nourish the hope that the new approach is capable of modeling phase diagrams for ternary systems by means of binary interaction parameters only.

     

The variations of the configurational and solvency properties of low molecular weight sodium polyacrylate with ionic strength

The configurational and solvency properties of low molecular weight sodium polyacrylate have been determined for a wide range of ionic strength solutions, from intrinsic viscosity data in the polymer literature.The variations of the polymer properties with ionic strength (I) are described very well by simple mathematical expressions. Thus, a linear relationship was found between the solvency parameter and 1/I ^(1/2), while the variations of the expansion factor and the radius of gyration with 1/I ^(1/2) were described by second order polynomials.LowI solutions (i.e. < 0.01) have a high solvency for sodium polyacrylate. In such solutions the polymer is in a highly expanded configuration. Thus, the radius of gyration of a typical, low molecular weight (ca. 5000 g mol^–1) sodium polyacrylate approaches the limiting value of ca. 4.5 nm atI<0.01.Conversely, high ionic strength solutions (i.e. >0.10) have a low solvency for sodium polyacrylate. In such solutions the polymer is in a virtually unexpanded configuration. Thus, the radius of gyration of a typical, low molecular weight sodium polyacrylate approaches the limiting value of ca. 2.0 nm atI>0.10.     

具有偿付约束的衍生证券市场均衡存在性

本文通过一个简单的模型,证明了具有偿付约束的衍生证券市场均衡的存在性,由此解释了衍生证券市场的起因和衍生证券交易所的建立过程.这一结论很好地解释了市场摩擦对均衡存在性的影响,与无摩擦时均衡未必存在在形成了鲜明的对照.     

Full and 1‐year runoff risk in the credibility‐based additive loss reserving method

In this paper, we consider the additive loss reserving (ALR) method in a Bayesian and credibility setup. The classical ALR method is a simple claims reserving method that combines prior information (e.g., premiums, number of contracts, market statistics) with claims observations. The Bayesian setup, which we present, in addition, allows for combining the information from a single runoff portfolio (e.g., company‐specific data) with the information from a collective (e.g., industry‐wide data) to analyze the claims reserves and the claims development result. However, in insurance practice, the associated distributions are usually unknown. Therefore, we do not follow the full Bayesian approach but apply credibility theory, which is distribution free and where we only need to know the first and second moments. That is, we derive the credibility predictors that minimize the expected squared loss within the class of affine‐linear functions of the observations (i.e., we derive linear Bayesian predictors). Using non‐informative priors, we link our credibility‐based ALR method to the classical ALR method and show that the credibility predictors coincide with the predictors in the classical ALR method. Moreover, we quantify the 1‐year risk and the full reserve risk by means of the conditional mean square error of prediction. Copyright © 2011 John Wiley & Sons, Ltd.     

偿付能力监管中审核问题博弈分析

偿付能力监管是我国保险监管体系的三大支柱之一,居于监管体系的核心地位,然而保险人报送的不真实数据严重影响了偿付能力监管的效果.将对监管机构和保险人的行为进行分析,建立博弈模型,研究在偿付能力监管过程中,监管机构如何通过审核制度设计保证被监管者报送数据的真实性,并在此条件下对审核制度影响因素进行分析.     

The effect ofn-butyl glycol ethers on the phase diagrams of microemulsions formulated with nonionic surfactants

The effect ofn-butyl glycol ethers used as cosurfactants on the microemulsions formulated with two nonionic surfactants, hexaoxyethylene glycol monolauryl ether and sorbitan monolaurate, is presented on ternary phase diagrams. The solubilization parameters as well as isothermal invariant points (IIP) of microemulsions were correlated with the solubility parameters of cosurfactants. An optimum solubility parameter of cosurfactants was established around 9 (cal/cm³)^1/2 where both IIP and solubilization parameters are optimal for water and oil solubilization with the lowest concentration of amphiphilic compounds. The mixture of cosurfactants can be used to obtain a certain transition on the phase diagram and so to achieve certain characteristics for microemulsions, especially to tailor the solvency of the system.On leave from the University of Bucharest Department of Physical Chemistry Bdul Republicii 13 Bucharest, Romania     

Annual intrinsic value of a company in a competitive insurance market

In this paper we analyze a measure of the insurance company’s value in an extended Lundberg model which includes the effect of competition on pricing. The extended model is designed to be an integral part of a multi-year controlled risk model of a company operating on both competitive insurance and financial markets, when insureds migrate in seeking for better rates and investors migrate in seeking for higher return on investments.