Optimal risk control policies for diffusion models with non-cheap proportional reinsurance and bankruptcy value

This paper considers the problem about optimization of proportional reinsurance in the setting of diffusion models. The authors take into account non-cheap proportional reinsurance and bankruptcy value simultaneously. The objective is to find the risk control policies which maximize the total discounted reserve and the bankruptcy value. Results show that, the optimal risk control policies and corresponding optimal return functions vary, depending both on the range of bankruptcy value and the relationship between the premium rate of insurance and that of reinsurance.     

Optimal investment problem for an insurer and a reinsurer

This paper studies the optimal investment problem for an insurer and a reinsurer. The basic claim process is assumed to follow a Brownian motion with drift and the insurer can purchase proportional reinsurance from the reinsurer. The insurer and the reinsurer are allowed to invest in a risk-free asset and a risky asset. Moreover, the authors consider the correlation between the claim process and the price process of the risky asset. The authors ?rst study the optimization problem of maximizing the expected exponential utility of terminal wealth for the insurer. Then with the optimal reinsurance strategy chosen by the insurer, the authors consider two optimization problems for the reinsurer: The problem of maximizing the expected exponential utility of terminal wealth and the problem of minimizing the ruin probability. By solving the corresponding Hamilton-Jacobi-Bellman equations, the authors derive the optimal reinsurance and investment strategies, explicitly. Finally, the authors illustrate the equality of the reinsurer's optimal investment strategies under the two cases.     

Optimal reinsurance and investment strategies for insurers with regime-switching and state-dependent utility function

This paper considers a proportional reinsurance-investment problem and an excess-of-loss reinsurance-investment problem for an insurer, where price processes of the risky assets and wealth process of the insurer are both described by Markovian regime switching. The target of the insurer is assumed to maximize the expected exponential utility from her terminal wealth with a state-dependent utility function. By employing the dynamic programming approach, the optimal value functions and the optimal reinsurance-investment strategies are derived. In addition, the impact of some parameters on the optimal strategies and the optimal value functions is analyzed, and lots of interesting results are discovered, such as the conclusion that excess-of-loss reinsurance is better than proportional reinsurance is not held in the regime-switching jump-diffusion model.     

Minimizing the Risk of Absolute Ruin Under a Diffusion Approximation Model with Reinsurance and Investment

This paper studies the optimization problem with both investment and proportional reinsurance control under the assumption that the surplus process of an insurance entity is represented by a pure diffusion process.The company can buy proportional reinsurance and invest its surplus into a Black-Scholes risky asset and a risk free asset without restrictions.The authors define absolute ruin as that the liminf of the surplus process is negative infinity and propose absolute ruin minimization as the optimization scenario.Applying the HJB method the authors obtain explicit expressions for the minimal absolute ruin function and the associated optimal investment strategy.The authors find that the minimal absolute ruin function here is convex,but not S-shaped investigated by Luo and Taksar(2011).And finally,from behavioral finance point of view,the authors come to the conclusion:It is the restrictions on investment that results in the kink of minimal absolute ruin function.     

Optimal investment and proportional reinsurance in the Sparre Andersen model

From the insurer’s point of view,this paper studies the optimal investment and proportional reinsurance in the Sparre Andersen model.Under the criterion of maximizing the adjustment coefficient, the authors obtain the closed form expressions of the optimal strategy and the maximal adjustment coefficient,and derive the explicit expression of the ruin probability or its lower bound when the claim sizes are exponentially distributed.Some numerical examples are presented,which show the impact of model parameters on the optimal values.It can also be seen that the optimal strategy to maximize the adjustment coefficient is sometimes equivalent to those which minimize the ruin probability.     

S型效用下比例再保险的最优投资策略

本文引入了行为金融学中的损失厌恶概念,研究考虑损失厌恶时保险公司的最优投资再保险问题.在损失厌恶下,保险公司面对盈利时是风险厌恶者,而遭受损失时转为风险追求者,因此本文采用S型效用函数,并以终端财富的效用最大化为目标求解保险公司的最优策略.假定保险公司的盈余过程服从经典的Cramer-Lundberg模型,可将资产投资于一种无风险资产和一种服从几何布朗运动的风险资产,且可以通过向再保险公司购买比例再保险来分散风险、稳定经营.通过构造鞅过程,运用鞅方法和拉格朗日对偶法求解出最优策略与最优财富.最后进行数值分析,更加直观地解释了各经济参数对财富值和投资策略的影响.     

考虑违约风险的兼顾保险公司与再保险公司利益的最优投资与再保险问题研究

本文主要研究了考虑违约风险的兼顾保险公司与再保险公司共同利益的最优投资与再保险问题.假设索赔过程由带漂移的几何布朗运动描述,保险公司可以投资于一无风险资产、一支股票和一可违约债券,再保险公司可以投资于一无风险资产和一支股票.以两家公司终端财富的期望指数效用乘积最大为目标,采用随机控制理论建立优化问题对应的HJB方程,进而分别得到违约前和违约后的最优策略和价值函数.最后本文分析了各模型参数对最优投资和再保险策略的影响,并给出相应的经济解释.     

比例再保险模型的最优控制策略研究

在对一类带分红过程的比例再保险模型进行分析的过程中，不但把保险公司与再保公司在交易过程中需支付的交易费用考虑进去，而且还考虑了公司破产时的补偿值这一重要因素，以此为基础建立了一种新的模型，从而弥补了传统模型的不足．为使公司获得最大的风险回报，针对不同的市场参数，对此新模型进行了详尽的技术分析，给出了不同情形下所应采取的最优控制策略，得出了相应的最大风险回报函数．     

Optimal Reinsurance Under Distortion Risk Measures and Expected Value Premium Principle for Reinsurer

This paper discusses optimal reinsurance strategy by minimizing insurer’s risk under one general risk measure:Distortion risk measure.The authors assume that the reinsurance premium is determined by the expected value premium principle and the retained loss of the insurer is an increasing function of the initial loss.An explicit solution of the insurer’s optimal reinsurance problem is obtained.The optimal strategies for some special distortion risk measures,such as value-at-risk(VaR) and tail value-at-risk(TVaR),are also investigated.     

风险调整资本收益率下的最优再保险策略

引入金融行业中用在风险管理和绩效评估等方面的指标——风险调整资本收益率,构建了基于该指标的再保险策略风险模型.对于常用的成数再保险和停止损失再保险,通过分析得出了使得保险人风险调整资本收益率最大化的自留风险比率和自留风险额度.同时发现:对于成数再保险,保险人可以通过自留所有风险来获得最大的风险调整资本收益率;而对于停止损失再保险,如果保险偿付能力监管的资本要求足够严格,保险人存在一个最优的自留风险额度.在此额度下,保险人能够获得比保留所有风险更大的风险调整资本收益率.     

Optimal combinational of quota-share and stop-loss reinsurance contracts under VaR and CTE with a constrained reinsurance premium

This paper considers the problem of minimizing the VaR and CTE of an insurer’s retained risk by controlling the combinational quota-share and stop-loss reinsurance strategy. With a constrained reinsurance premium, the authors give the explicit reinsurance forms and the minimal VaR and CTE of retained risk in the case of quota-share after stop-loss reinsurance and the case of stop-loss after-quota-share reinsurance respectively. Finally, the authors conclude that the quota-share after stop-loss is a better reinsurance strategy than stop-loss after quota-share to minimize the VaR and CTE with a same constrained reinsurance premium. And the pure stop-loss reinsurance is preferred for an insurer with a high level regulatory requirement.     

再保险定价的研究

对再保险的作用进行了说明,针对比例再保险和非比例再保险,建立了再保险定价的倒向随机微分方程,并进行了再保险价值研究。再保险定价方法以随机过程为基础,与传统的以概率统计为基础的再保险定价方法有明显的不同,它不用考虑死亡率、损失的概率分布等因素,为再保险定价提供了新的思路,丰富了有限的再保险定价方法,有重要的理论和实际意义。     

投资连结产品的再保险策略

对趸缴保费和分期缴纳保费两种情况，在投资基金服从对数正态分布的假定下，研究投资连结产品在经营期内每年的最优比例再保险和超额损失再保险策略，所得结论对保险人做此决策具有直接的指导作用。     

A Stochastic Model on One-Unit Repairable Systems with Multiple Degenerative States

This paper studies a maintenance model for an one-unit degenerative system with multiple failure states based on the proportional hazards and proportional reversed hazards models. The authors investigate how the variation of system configuration parameters have an impact on both operating and repair times and hence the system performance. Furthermore, the authors also derive the explicit expression for the long-run average cost per unit time. An algorithm to locate the optimal number of repairs in a renewal cycle is discussed as well.     

基于偿付能力的最优再保险策略

采用最大索赔再保费定价原则,结合VaR、CTE、TV三种风险测度方法,通过研究最小化偿付不足风险的概率、期望损失以及均方期望超额损失等再保险问题,得到相应的最优再保险策略,并结合案例对各种最优策略进行静态分析.研究发现,当偿付能力基于VaR或者CTE时,最优的再保险策略是去尾停止损失再保险,这说明原保险公司此时应该更注重对中等巨额损失的保障,而没有动力去保障极值损失;当偿付能力基于TV时,最优策略是带限额的停止损失再保险,此时,保险公司为了保证经营的稳定性,势必会将一部分极值损失分保.     

随机巨灾索赔相依风险模型的动态最优再保险

在索赔风险时变、相依条件下,建立随机巨灾的可调态再保险模型.在指明超额赔款再保险为最优分保形式的基础上,讨论并发现目标函数随自留巨灾风险水平的增大,在任意相依结构下均先减后增的变化定理,从而获得了自留向量的一般性显式表达式.根据巨灾风险的特征,还在一类特定的相依结构下,以自留风险的期望效用和方差为优化目标,对自留向量进行了更为明确的表示并给出具体示例.结果表明,随着巨灾风险相依强度的上升,分保的满意度降低,经营稳定性减弱,对保险公司的负面影响很大.此时,为实现客观风险下的分保目标最优,常规风险的自留水平应随之增大,体现了动态再保险的优越性.     

An adaptive Lagrangian algorithm for optimal portfolio deleveraging with cross-impact

This paper considers the problem of optimal portfolio deleveraging, which is a crucial problem in finance. Taking the permanent and temporary price cross-impact into account, the authors establish a quadratic program with box constraints and a singly quadratic constraint. Under some assumptions, the authors give an optimal trading priority and show that the optimal solution must be achieved when the quadratic constraint is active. Further, the authors propose an adaptive Lagrangian algorithm for the model, where a piecewise quadratic root-finding method is used to find the Lagrangian multiplier. The convergence of the algorithm is established. The authors also present some numerical results, which show the usefulness of the algorithm and validate the optimal trading priority.     

Generalized weighted functional proportional mean combining forecasting model and its method of parameter estimation

1 .INTRODUCTIONCombiningforecastinghasbroughtgreatattentiontobytheforecastingcirclessince 196 9whenJ .M .BatesandC .W .J .Grangerproposeditstheoryandmethod[1] .Thetheoryandmethodsofcombiningforecastinghavebeendevelopedwidelyinrecentyears .Forpracticalcase…     

Optimal Switching Integrity Attacks on Sensors in Industrial Control Systems

In this article, an optimal switching integrity attack problem is investigated to study the response of feedback control systems under attack. The authors model the malicious attacks on sensors as additive norm bounded signals. The authors consider an attacker who is only capable of launching attacks to limited number of sensors once a time and changing the combinations of attacked sensors all over the time. The objective of this paper is to find the optimal switching sequence of these combinations and the optimal attack input. The authors solve this problem by transforming it into a traditional optimal control problem with new control variables vary continuously in the range [0, 1]. The optimal solutions of the new control variables are of bang-bang-type. Therefore, an algebraic switching condition and an optimal attack input can be obtained. Finally, numerical results are provided to illustrate the effectiveness of the methods.     

交货期服从指数分布的单机随机调度问题

工件完成时间与交货期差的绝对值加权和最小化单机随机调度问题是JIT（just-in-time)生产环境下的典型调度模型，是NP－hard问题，然而，当工件权值与加工时间成正比时，LPT（largest processing time）工件调度是问题的最优解，讨论了该问题加工时间和交货期都为随机变量，其中交货期服从指数分布，且工件权值与加工时间成正比的情形，给出了问题的最优解，并在一定条件下将结果推广到机器随机故障的情形。