This paper focuses on an optimal reinsurance and investment problem for an insurance corporation which holds the shares of an insurer and a reinsurer.Assume that the insurer can purchase reinsurance from the reinsurer...This paper focuses on an optimal reinsurance and investment problem for an insurance corporation which holds the shares of an insurer and a reinsurer.Assume that the insurer can purchase reinsurance from the reinsurer,and that both the insurer and the reinsurer are allowed to invest in a risk-free asset and a risky asset which are governed by the Heston model and are distinct from one another.We aim to find the optimal reinsuranceinvestment strategy by maximizing the expected Hyperbolic Absolute Risk Aversion(HARA)utility of the insurance corporation’s terminal wealth,which is the weighted sum of the insurer’s and the reinsurer’s terminal wealth.The Hamilton-Jacobi-Bellman(HJB)equation is first established.However,this equation is non-linear and is difficult to solve directly by any ordinary method found in the existing literature,because the structure of this HJB equation is more complex under HARA utility.In the present paper,the Legendre transform is applied to change this HJB equation into a linear dual one such that the explicit expressions of optimal investment-reinsurance strategies for-1≤ρi≤1 are obtained.We also discuss some special cases in a little bit more detail.Finally,numerical analyses are provided.展开更多
A new phenolic constituent along with five known compounds were isolated from Fagopyrum dibotrys (D.Don) Hara. The new compound was characterized as 1,3-dimethoxy-2-O-β-xylo-pyranosyl-5-O-β-glucopyranosyl-benzene, b...A new phenolic constituent along with five known compounds were isolated from Fagopyrum dibotrys (D.Don) Hara. The new compound was characterized as 1,3-dimethoxy-2-O-β-xylo-pyranosyl-5-O-β-glucopyranosyl-benzene, by spectroscopic analysis and enzymatic hydrolysis.展开更多
This paper analyzes an open pit gold mine project based on the O'Hara cost model. Hypothetical data is proposed based on different authors that have studied open pit gold projects, and variations are proposed acco...This paper analyzes an open pit gold mine project based on the O'Hara cost model. Hypothetical data is proposed based on different authors that have studied open pit gold projects, and variations are proposed according to the probability distributions associated to key variables affecting the NPV, like production level, ore grade, price of ore, and others, so as to see what if, in a gold open pit mine project of 3000 metric tons per day of ore. Two case scenarios were analyzed to simulate the NPV, one where there is low certainty data available, and the other where the information available is of high certainty. Results based on genetic algorithm metaheuristic simulations, which combine basically Montecarlo simulations provided by the Palisade Risk software, the O'Hara cost model, net smelter return and financial analysis tools offered by Excel are reported, in order to determine to which variables of the project is more sensitive the NPV.展开更多
Cerospora sojina Hara. toxin produced by mycelia of the pathogen can harm soybean plants. In this paper, 50 varieties and one resistant-susceptible combination were used to study the toxin resistance and it's inhe...Cerospora sojina Hara. toxin produced by mycelia of the pathogen can harm soybean plants. In this paper, 50 varieties and one resistant-susceptible combination were used to study the toxin resistance and it's inheritance. Comparing the results from the field under different inoculation conditions, the average coincidence rate of the toxin test is 62.37%. The inheritance of resistance to the toxin of Race 7 of Cerospora sojina Hara was proved to be controlled by a pair of single dominant genes. The toxin appraisal method can be used for many purposes owing to it's convenience.展开更多
[ Objective] This study aimed to conduct the karyotype analysis of Rabdosia lophanthoides var. gerardians and R. lophanthoides Hara var. gracilifloruschromosomes. [ Method] Vigorously growing shoot tips of R. lophanth...[ Objective] This study aimed to conduct the karyotype analysis of Rabdosia lophanthoides var. gerardians and R. lophanthoides Hara var. gracilifloruschromosomes. [ Method] Vigorously growing shoot tips of R. lophanthoides var. gerardianus and R. lophanthoides Hara var. graciliflorus were stained for section preparation to observe and analyze the chromosomes. [ Result] Karyotype formula of R. lophanthoides var. gerardianus is K （2n） =2x =24 = 18m ＋4Sm, sugges- ting that this species belongs to category 2A of Stebbins; karyotype formula of R. lophanthoides Hara var. graciliflorus is K （2n） =2x =24 = 16m ＋8Sm, sugges- ting that this species belongs to category 1B of Stebbins. [Conclusion] R. lophanthoides var. gerardianus is more primitive compared with R. lophanthoides Hara var. graciliflorus.展开更多
This paper studies a defined contribution(DC)pension fund investment problem with return of premiums clauses in a stochastic interest rate and stochastic volatility environment.In practice,most of pension plans were s...This paper studies a defined contribution(DC)pension fund investment problem with return of premiums clauses in a stochastic interest rate and stochastic volatility environment.In practice,most of pension plans were subject to the return of premiums clauses to protect the rights of pension members who died before retirement.In the mathematical modeling,we assume that a part of pension members could withdraw their premiums if they died before retirement and surviving members could equally share the difference between accumulated contributions and returned premiums.We suppose that the financial market consists of a risk-free asset,a stock,and a zero-coupon bond.The interest rate is driven by a stochastic affine interest rate model and the stock price follows the Heston’s stochastic volatility model with stochastic interest rates.Different fund managers have different risk preferences,and the hyperbolic absolute risk aversion(HARA)utility function is a general one including a power utility,an exponential utility,and a logarithm utility as special cases.We are concerned with an optimal portfolio to maximize the expected utility of terminal wealth by choosing the HARA utility function in the analysis.By using the principle of dynamic programming and Legendre transform-dual theory,we obtain explicit solutions of optimal strategies.Some special cases are also derived in detail.Finally,a numerical simulation is provided to illustrate our results.展开更多
基金supported by Natural Science Foundation of China(1187127511371194)。
文摘This paper focuses on an optimal reinsurance and investment problem for an insurance corporation which holds the shares of an insurer and a reinsurer.Assume that the insurer can purchase reinsurance from the reinsurer,and that both the insurer and the reinsurer are allowed to invest in a risk-free asset and a risky asset which are governed by the Heston model and are distinct from one another.We aim to find the optimal reinsuranceinvestment strategy by maximizing the expected Hyperbolic Absolute Risk Aversion(HARA)utility of the insurance corporation’s terminal wealth,which is the weighted sum of the insurer’s and the reinsurer’s terminal wealth.The Hamilton-Jacobi-Bellman(HJB)equation is first established.However,this equation is non-linear and is difficult to solve directly by any ordinary method found in the existing literature,because the structure of this HJB equation is more complex under HARA utility.In the present paper,the Legendre transform is applied to change this HJB equation into a linear dual one such that the explicit expressions of optimal investment-reinsurance strategies for-1≤ρi≤1 are obtained.We also discuss some special cases in a little bit more detail.Finally,numerical analyses are provided.
文摘A new phenolic constituent along with five known compounds were isolated from Fagopyrum dibotrys (D.Don) Hara. The new compound was characterized as 1,3-dimethoxy-2-O-β-xylo-pyranosyl-5-O-β-glucopyranosyl-benzene, by spectroscopic analysis and enzymatic hydrolysis.
基金the Mine Planning Research Group–GIPLAMIN-of the Mines Faculty,National University of Colombia
文摘This paper analyzes an open pit gold mine project based on the O'Hara cost model. Hypothetical data is proposed based on different authors that have studied open pit gold projects, and variations are proposed according to the probability distributions associated to key variables affecting the NPV, like production level, ore grade, price of ore, and others, so as to see what if, in a gold open pit mine project of 3000 metric tons per day of ore. Two case scenarios were analyzed to simulate the NPV, one where there is low certainty data available, and the other where the information available is of high certainty. Results based on genetic algorithm metaheuristic simulations, which combine basically Montecarlo simulations provided by the Palisade Risk software, the O'Hara cost model, net smelter return and financial analysis tools offered by Excel are reported, in order to determine to which variables of the project is more sensitive the NPV.
文摘Cerospora sojina Hara. toxin produced by mycelia of the pathogen can harm soybean plants. In this paper, 50 varieties and one resistant-susceptible combination were used to study the toxin resistance and it's inheritance. Comparing the results from the field under different inoculation conditions, the average coincidence rate of the toxin test is 62.37%. The inheritance of resistance to the toxin of Race 7 of Cerospora sojina Hara was proved to be controlled by a pair of single dominant genes. The toxin appraisal method can be used for many purposes owing to it's convenience.
文摘[ Objective] This study aimed to conduct the karyotype analysis of Rabdosia lophanthoides var. gerardians and R. lophanthoides Hara var. gracilifloruschromosomes. [ Method] Vigorously growing shoot tips of R. lophanthoides var. gerardianus and R. lophanthoides Hara var. graciliflorus were stained for section preparation to observe and analyze the chromosomes. [ Result] Karyotype formula of R. lophanthoides var. gerardianus is K （2n） =2x =24 = 18m ＋4Sm, sugges- ting that this species belongs to category 2A of Stebbins; karyotype formula of R. lophanthoides Hara var. graciliflorus is K （2n） =2x =24 = 16m ＋8Sm, sugges- ting that this species belongs to category 1B of Stebbins. [Conclusion] R. lophanthoides var. gerardianus is more primitive compared with R. lophanthoides Hara var. graciliflorus.
基金supported by the National Social Science Foundation of China (No.21FJYB042)。
文摘This paper studies a defined contribution(DC)pension fund investment problem with return of premiums clauses in a stochastic interest rate and stochastic volatility environment.In practice,most of pension plans were subject to the return of premiums clauses to protect the rights of pension members who died before retirement.In the mathematical modeling,we assume that a part of pension members could withdraw their premiums if they died before retirement and surviving members could equally share the difference between accumulated contributions and returned premiums.We suppose that the financial market consists of a risk-free asset,a stock,and a zero-coupon bond.The interest rate is driven by a stochastic affine interest rate model and the stock price follows the Heston’s stochastic volatility model with stochastic interest rates.Different fund managers have different risk preferences,and the hyperbolic absolute risk aversion(HARA)utility function is a general one including a power utility,an exponential utility,and a logarithm utility as special cases.We are concerned with an optimal portfolio to maximize the expected utility of terminal wealth by choosing the HARA utility function in the analysis.By using the principle of dynamic programming and Legendre transform-dual theory,we obtain explicit solutions of optimal strategies.Some special cases are also derived in detail.Finally,a numerical simulation is provided to illustrate our results.
