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161.
162.
基于最速下降法的基本思想 ,提出了相互逼近算法 ,用以解决信贷风险决策过程中 ,利润曲线和风险曲线寻求公共最优近似解的问题 .该算法表明 ,当利润曲线和风险曲线不存在公共最优近似解时 ,银行追求利润最大化的结果将导致风险上升 ,无法在可接受的风险指数范围内实现其既定的盈利目标 .但当利润曲线和风险曲线存在公共最优近似解时 ,银行根据其所掌握的私有信息以及所观测到企业理性的反应 ,作出相应的决策 .公共最优近似解的存在 ,说明了银行是在风险可接受的前提下按最优性原则给企业发放贷款 . 相似文献
163.
164.
ABSTRACT. Habitat loss and fragmentation are considered to be the most important factors responsible for population decreases in small mammal populations. Particularly important is also the effect of insularity that can act syn‐ergistically with the previous factors. Population Viability Analysis (PVA) combines the spatial component of the problem with the species population structure offering an integrated platform for testing and assessing the effects of critical parameters upon the population viability. Various management options can also be quantified and tested. In the case of Sciurus anomalous, a vulnerable squirrel species endemic in Lesvos, a series of threats and management problems were identified and assessed. A stochastic simulation model was developed and parameterized with field data for the species using the program Ramas/GIS. The results suggested that special attention has to be paid to the planning of road system networks and to stopping illegal hunting, especially when extinction risks for vulnerable populations are higher with the above threats. 相似文献
165.
一类组合投资问题的线性规划解法 总被引:3,自引:0,他引:3
根据选定总体风险的一个上界值使组合投资的收益率达到最大的原则,并在合理简化的基础上建立组合投资决策问题的线性规划模型。然后通过算例求解带有参数的线性规划问题,给出资产组合的风险控制值和相应的最大净收益率及投资比例向量的关系。 相似文献
166.
This paper is a further investigation into the large deviations for random sums of heavy-tailed,we extended and improved some results in ref. [1] and [2]. These results can applied to some questions in Insurance and Finance. 相似文献
167.
Yuzo Hosoya 《Annals of the Institute of Statistical Mathematics》1990,42(1):37-49
By means of second-order asymptotic approximation, the paper clarifies the relationship between the Fisher information of first-order asymptotically efficient estimators and their decision-theoretic performance. It shows that if the estimators are modified so that they have the same asymptotic bias, the information amount can be connected with the risk based on convex loss functions in such a way that the greater information loss of an estimator implies its greater risk. The information loss of the maximum likelihood estimator is shown to be minimal in a general set-up. A multinomial model is used for illustration. 相似文献
168.
This paper estimates the price for restructuring risk in the US corporate bond market during 1999–2005. Comparing quotes from default swap (CDS) contracts with a restructuring event and without, we find that the average premium for restructuring risk represents 6%–8% of the swap rate without restructuring. We show that the restructuring premium depends on firm-specific balance-sheet and macroeconomic variables. And, when default swap rates without a restructuring event increase, the increase in restructuring premia is higher for low-credit-quality firms than for high-credit-quality firms. We propose a reduced-form arbitrage-free model for pricing default swaps that explicitly incorporates the distinction between restructuring and default events. A case study illustrating the model’s implementation is provided. 相似文献
169.
通过对方程组Ax=b的系数矩阵施行初等行变换,该文提出了解线性方程组Ax=b的一种新的预条件Gauss Seidel迭代方法,理论上证明了新的预条件Gauss Seidel迭代方法较经典的Gauss Seidel迭代法收敛速度快. 该文提出的新预条件方法推广了文[1-2]中提出的预条件方法,具体的数值例子说明了新预条件方法的有效性. 相似文献
170.
Lilia Yu. Kolotilina 《Numerical Algorithms》2006,42(3-4):247-280
Using a unified approach based on the monotonicity property of the Perron root and its circuit extension, a series of exact two-sided bounds for the Perron root of a nonnegative matrix in terms of paths in the associated directed graph is obtained. A method for deriving the so-called mixed upper bounds is suggested. Based on the upper bounds for the Perron root, new diagonal dominance type conditions for matrices are introduced. The singularity/nonsingularity problem for matrices satisfying such conditions is analyzed, and the associated eigenvalue inclusion sets are presented. In particular, a bridge connecting Gerschgorin disks with Brualdi eigenvalue inclusion sets is found. Extensions to matrices partitioned into blocks are proposed. 相似文献