One of the most important responsibilities of a supply chain manager is to decide “how much” (or “many”) of inventory items to order and how to transport them. This paper presents four mixed-integer linear program...One of the most important responsibilities of a supply chain manager is to decide “how much” (or “many”) of inventory items to order and how to transport them. This paper presents four mixed-integer linear programming models to help supply chain managers make these decisions for multiple products subject to multiple constraints when suppliers offer quantity discounts and shippers offer freight discounts. Each model deals with one of the possible combinations of all-units, incremental quantity discounts, all-weight and incremental freight discounts. The models are based on a piecewise linear approximation of the number of orders function. They allow any number of linear constraints and determine if independent or common (fixed) cycle ordering has a lower total cost. Results of computational experiments on an example problem are also presented.展开更多
In this present paper, a deterministic lot size model is developed for deteriorating items with incremental quantity discounts. It is assumed that shortages are permitted to occur and fully backlogged. A simple solut...In this present paper, a deterministic lot size model is developed for deteriorating items with incremental quantity discounts. It is assumed that shortages are permitted to occur and fully backlogged. A simple solution procedure is shown for determining the optimal order lot size and the optimal order cycle. A numerical example is used to illustrate how the solution procedure works.展开更多
Private placement has become an increasingly important method of equity refinancing for regulators, listed companies, and investors. This paper analyzes factors influencing private placement discounts based on the con...Private placement has become an increasingly important method of equity refinancing for regulators, listed companies, and investors. This paper analyzes factors influencing private placement discounts based on the controlling shareholder's opportunistic behavior and information asymmetry. Our findings indicate that the type of subscriber is a key determinant of the private placement discount, particularly when the subscriber is the controlling shareholder. Asymmetric information between listed companies and investors is another important determinant: The higher the degree of information asymmetry, the greater the private placement discounts.展开更多
BACKGROUND The role of physical activity in diabetes is critical,influencing this disease's development,man-agement,and overall outcomes.In China,22.3%of adults do not meet the minimum level of physical activity r...BACKGROUND The role of physical activity in diabetes is critical,influencing this disease's development,man-agement,and overall outcomes.In China,22.3%of adults do not meet the minimum level of physical activity recommended by the World Health Organization.Therefore,it is imperative to identify the factors that contributing to lack of physical activity must be identified.AIM To investigate the relationship among delay discounting,delay aversion,glycated hemoglobin(HbA1c),and various levels of physical activity in Chinese adults diagnosed with type 2 diabetes mellitus(T2DM).METHODS In 2023,400 adults with T2DM were recruited from the People's Hospital of Linxia Hui Autonomous Prefecture of Gansu Province.A face-to-face questionnaire was used to gather demographic data and details on physical activity,delay discounting,and delay aversion.In addition,HbA1c levels were measured in all 400 participants.The primary independent variables considered were delay discounting and delay aversion.The outcome variables included HbA1c levels and different intensity levels of physical activity,including walking,moderate physical activity,and vigorous physical activity.Multiple linear regression models were utilized to assess the relationship between delay discounting,delay aversion,and HbA1c levels,along with the intensity of different physical activity measured in met-hours per week.RESULTS After controlling for the sample characteristics,delay discounting was negatively associated with moderate physical activity(β=-2.386,95%CI:-4.370 to-0.401).Meanwhile,delay aversion was negatively associated with the level of moderate physical activity(β=-3.527,95%CI:-5.578 to-1.476)in the multiple linear regression model,with statistically significant differences.CONCLUSION Elevated delay discounting and increased delay aversion correlated with reduced levels of moderate physical activity.Result suggests that delay discounting and aversion may influence engagement in moderate physical activity.This study recommends that health administration and government consider delay discounting and delay aversion when formulating behavioral intervention strategies and treatment guidelines involving physical activity for patients with T2DM,which may increase participation in physical activity.This study contributes a novel perspective to the research on physical activity in adults with T2DM by examining the significance of future health considerations and the role of emotional responses to delays.展开更多
The polynomial spline model, which belongs to the static term structure model of interest rates, is studied. Every cash flow of the project is discounted relatively accurately by obtaining the discount rate from the s...The polynomial spline model, which belongs to the static term structure model of interest rates, is studied. Every cash flow of the project is discounted relatively accurately by obtaining the discount rate from the static term structure model of interest rates. A simple basic model, which belongs to the dynamic term structure model, is studied, and the option pricing formula under changing risk-free rates is obtained by bringing it into the option pricing formula. Both dynamic and static term structure models are estimated by the use of the data of buy-back rates and the Shanghai Stock Exchange, and an example is given to compare the differences between the traditional method and the method under the changes in the interest rates and the discount rates.展开更多
With Internet changing the luxury business landscape,new players have emerged such as the Online Private Sales Retailers(OPSRs).These offer online buyers with a choice of limited-time sales to help companies get rid o...With Internet changing the luxury business landscape,new players have emerged such as the Online Private Sales Retailers(OPSRs).These offer online buyers with a choice of limited-time sales to help companies get rid of their overstocks.Luxury brands are no exception.No research has been conducted about how luxury consumers relate with such websites,hence this paper.In an exploratory fashion,interviews with luxury buyers who also buy online on OPSRs,are conducted to get insights on consumers’perceptions and luxury brand equity that selling through OPSRs may have.We find that appropriate product and brand help consumers forget that they are buying brands’unsold stocks,that transferring the luxury webmospheres would be positively perceived,that consumers from these websites are looking for benefits such as freedom of use and brand discovery,rather than personalized offers,that multiple discounts on several OPSRs may damage the luxury-perception of a brand,that the private sales members consider the service to be good enough for the demanded price,and that personalized invitations can help increase online consumers’feelings of desirability and exclusivity.The paper concludes with practical recommendations for both luxury companies and OPSRs.展开更多
The development and deployment of privary preserving supply chain quantity discount contract design can allow supply chain collaborations to take place without revealing any participant's data to others, reaping the ...The development and deployment of privary preserving supply chain quantity discount contract design can allow supply chain collaborations to take place without revealing any participant's data to others, reaping the benefits of collaborations wbile avoiding the drawbacks of privacy information disclosure. First, secure multi-party computation protocols are applied in the joint-ordering policy between a single supplier and a single retailer, the joint-ordering policy can be conducted without disclosing private cost information of any of the other supply chain partners. Secondly, secure multi-party computation protocols are applied in the privacy preserving supply chain quantity discount contract design between a single supplier and a single retailer. The information disclosure analyses of the algorithm show that: the optimal quantity discount of the jointordering policy can be conducted without disclosing private cost information of any of the other supply chain partners; the above protocol can be implemented without mediators; the privacy preserving quantity discount algorithm can be mutually verifiable and has solved the problem of asymmetric information.展开更多
Objective: Lung cancer is one of the leading cancers and major causes of cancer mortality worldwide. The economic burden associated with the high mortality of lung cancer is high, which accounts for nearly $180 billio...Objective: Lung cancer is one of the leading cancers and major causes of cancer mortality worldwide. The economic burden associated with the high mortality of lung cancer is high, which accounts for nearly $180 billion on a global scale in 2008. This paper aims to understand the economic burden of lung cancer in terms of disability adjusted life years(DALY) in Australia, the Philippines, and Singapore.Methods: The years of life lost(YLL) and years lost due to disability(YLD) were calculated using the formula developed by Murray and Lopez in 1996 as part of a comprehensive assessment of mortality and disability for diseases, injuries and risk factors in 1990 and projected to 2020. The same formula is represented in the Global Burden of Disease template provided by the World Health Organization. Appropriate assumptions were made when data were unavailable and projections were performed using regression analysis to obtain data for 2015.Results: The total DALYs due to lung cancer in Australia, the Philippines, and Singapore were 91,695, 38,584, and 12,435,respectively, and the corresponding DALY rates per a population of 1,000 were 4.0, 0.4, and 2.2, respectively, with a discount rate of 3%. When researchers calculated DALYs without the discount rate, the burden of disease increased substantially; the DALYs were 117,438 in Australia, 50,977 in the Philippines, and 16,379 in Singapore. Overall, YLL or premature death accounted for more than 95% of DALYs in these countries.Conclusions: Strategies for prevention, early diagnosis, and prompt treatment must be devised for diseases where the major burden is due to mortality.展开更多
In this paper, a compound Poisson risk model with time-dependent claims is studiedunder a multi-layer dividend strategy. A piecewise integro-differential equation for the Gerber- Shiu function is derived and solved. A...In this paper, a compound Poisson risk model with time-dependent claims is studiedunder a multi-layer dividend strategy. A piecewise integro-differential equation for the Gerber- Shiu function is derived and solved. Asymptotic formulas of the ruin probability are obtained when the claim size distributions are heavy-tailed.展开更多
We consider that the reserve of an insurance company follows a renewal risk process with interest and dividend. For this risk process, we derive integral equations and exact infinite series expressions for the Cerber-...We consider that the reserve of an insurance company follows a renewal risk process with interest and dividend. For this risk process, we derive integral equations and exact infinite series expressions for the Cerber-Shiu discounted penalty function. Then we give lower and upper bounds for the ruin probability. Finally, we present exact expressions for the ruin probability in a special case of renewal risk processes.展开更多
Salinity is one of the major abiotic factors affecting the growth and productivity of crops in Hetao Irrigation District, China. In this study, the salinity tolerances of three local crops, wheat (Triticum aestinum L...Salinity is one of the major abiotic factors affecting the growth and productivity of crops in Hetao Irrigation District, China. In this study, the salinity tolerances of three local crops, wheat (Triticum aestinum L.), maize (Zea mays L.) and sunflower (Helianthus annuus L.), growing in 76 farm fields are evaluated with modified discount function. Salinity ecological zones appropriate for these local crops are characterized and a case study is presented for crop salinity ecological zoning. The results show that the yield reductions of wheat, maize and sunflower when grown in saline soils are attributed primarily to a reduction in spikelet number, 1 000-grain weight and seed number per head, respectively. Sunflower is the most tolerant crop among the three which had a salinity tolerance index (ST-index) of 12.24, followed by spring maize and spring wheat with ST-Indices of 9.00 and 7.43, respectively. According to the crop salinity tolerance results, the arable land in the Heping Village of this district was subdivided into four salinity ecological zones: the most suitable, suitable, sub-suitable and unsuitable zones. The area proportion of the most suitable zone for wheat, maize and sunflower within the Heping Village was 27.5, 46.5 and 77.5%, respectively. Most of the most suitable zone occurred in the western part of the village. The results of this study provide the scientific basis for optimizing the local major crop distribution and improving cultural practices management in Hetao Irrigation District.展开更多
The overseas oil and gas investment evaluation is one of the core tasks in overseas investment of oil and gas companies,among which risk evaluation and benefit evaluation are the most important.This paper sets forth t...The overseas oil and gas investment evaluation is one of the core tasks in overseas investment of oil and gas companies,among which risk evaluation and benefit evaluation are the most important.This paper sets forth transmission paths of risk factors to the investment benefit by identifying 14 overseas oil and gas investment risks in four categories.On the basis of the concept of risk compensation,different compensation mechanisms specific to each risk are designed.The risk and benefit are integrated objectively to develop a comprehensive evaluation model by correcting the recoverable reserve,adjusting benefit evaluation parameters such as investments on exploration and development,and compensating for the changes in risk factors with time through dynamic discount rate.Moreover,two cases studies,namely the evaluations of Project A in Sudan and comparison among Blocks A–G,are used to describe usage method and applicable scope of such evaluation model,respectively.According to the results,oil price is a key influencing factor for enterprise internal risk and industrial risk.Risk compensation reduces comprehensive benefit of overseas oil and gas investment and undermines the investment feasibility and priority of blocks.The research findings of this paper are free from the effects of some subject factors and avoid multi-objective decision making,and also avoid the undesired repeated calculation of risk factors.展开更多
In order to achieve the information fusion in the time domain based on the evidence theory, an evidence combination method in the time domain based on reliability and importance is proposed according to the idea of ev...In order to achieve the information fusion in the time domain based on the evidence theory, an evidence combination method in the time domain based on reliability and importance is proposed according to the idea of evidence discount. Firstly, the distortion of the time-domain evidence is judged based on single exponential smoothing. The real-time reliability of the evidence at the adjacent time is obtained by the real-time reliability assessment method of the evidence based on the credibility decay model.Then, the relative importance of the evidence at the adjacent time is obtained by comprehensively considering improved conflict degree and uncertainty. Finally, based on the criterion of evidence discount and the Dempster’s rule of combination, the evidence combination is carried out to achieve the sequential combination of time-domain evidence. The numerical simulation and analysis show that this method has fully embodied the dynamic characteristics of time-domain evidence combination, and it has strong processing ability for conflict information and anti-disturbing ability.The proposed method has good applicability to information fusion in the time domain.展开更多
The purpose of this paper is to consider the expected value of a discounted penalty due at ruin in the Erlang(2) risk process under constant interest force. An integro-differential equation satisfied by the expected...The purpose of this paper is to consider the expected value of a discounted penalty due at ruin in the Erlang(2) risk process under constant interest force. An integro-differential equation satisfied by the expected value and a second-order differential equation for the Laplace transform of the expected value are derived. In addition, the paper will present the recursive algorithm for the joint distribution of the surplus immediately before ruin and the deficit at ruin. Finally, by the differential equation, the defective renewal equation and the explicit expression for the expected value are given in the interest-free case.展开更多
The emergence of cooperation still remains a fundamental conundrum in the social and behavior sciences.We introduce a new mechanism,deposit mechanism,into theoretical model to explore how this mechanism promotes coope...The emergence of cooperation still remains a fundamental conundrum in the social and behavior sciences.We introduce a new mechanism,deposit mechanism,into theoretical model to explore how this mechanism promotes cooperation in a well-mixed population.Firstly,we extend the common binary-strategy combination of cooperation and defection in public good game by adding a third strategy,namely,deposit cooperation.The players with deposit cooperation strategy pay a deposit in advance to obtain the benefits of public good at a lower contributions compared with the players with cooperation strategy,when the provision of public good is successful.Then,we explore the evolution of cooperation in the public good game with deposit by means of the replicator dynamics.Theoretical computations and stimulations show that the deposit mechanism can promote cooperation in a well-mixed population,and the numbers of equilibrium point are determined by variables of public good game.On the one hand,when the coexistence of cooperators and defectors is the stable equilibrium point in the evolutionary system,increasing the threshold of public good and adopting the weak altruism way for share benefits can enhance the level of cooperation in the population.On the other hand,if the coexistence of deposit cooperators and defectors is the stable equilibrium point,it is effective to promote the deposit cooperation by lowering the values of discount and deposit,and raising the threshold of public good.展开更多
In the world, most of the successes are results of longterm efforts. The reward of success is extremely high, but before that, a long-term investment process is required. People who are “myopic” only value short-ter...In the world, most of the successes are results of longterm efforts. The reward of success is extremely high, but before that, a long-term investment process is required. People who are “myopic” only value short-term rewards and are unwilling to make early-stage investments, so they hardly get the ultimate success and the corresponding high rewards. Similarly, for a reinforcement learning(RL) model with long-delay rewards, the discount rate determines the strength of agent’s “farsightedness”.In order to enable the trained agent to make a chain of correct choices and succeed finally, the feasible region of the discount rate is obtained through mathematical derivation in this paper firstly. It satisfies the “farsightedness” requirement of agent. Afterwards, in order to avoid the complicated problem of solving implicit equations in the process of choosing feasible solutions,a simple method is explored and verified by theoreti cal demonstration and mathematical experiments. Then, a series of RL experiments are designed and implemented to verify the validity of theory. Finally, the model is extended from the finite process to the infinite process. The validity of the extended model is verified by theories and experiments. The whole research not only reveals the significance of the discount rate, but also provides a theoretical basis as well as a practical method for the choice of discount rate in future researches.展开更多
In this article, we consider an optimal proportional reinsurance with constant dividend barrier. First, we derive the Hamilton-Jacobi-Bellman equation satisfied by the expected discounted dividend payment, and then ge...In this article, we consider an optimal proportional reinsurance with constant dividend barrier. First, we derive the Hamilton-Jacobi-Bellman equation satisfied by the expected discounted dividend payment, and then get the optimal stochastic control and the optimal constant barrier. Secondly, under the optimal constant dividend barrier strategy, we consider the moments of the discounted dividend payment and their explicit expressions are given. Finally, we discuss the Laplace transform of the time of ruin and its explicit expression is also given.展开更多
This article addresses the problem of pricing European options when the underlying asset is not perfectly liquid.A liquidity discounting factor as a function of market-wide liquidity governed by a mean-reverting stoch...This article addresses the problem of pricing European options when the underlying asset is not perfectly liquid.A liquidity discounting factor as a function of market-wide liquidity governed by a mean-reverting stochastic process and the sensitivity of the underlying price to market-wide liquidity is firstly introduced,so that the impact of liquidity on the underlying asset can be captured by the option pricing model.The characteristic function is analytically worked out using the Feynman–Kac theorem and a closed-form pricing formula for European options is successfully derived thereafter.Through numerical experiments,the accuracy of the newly derived formula is verified,and the significance of incorporating liquidity risk into option pricing is demonstrated.展开更多
The classical Dempster's combination rule is the most popular rule of combinations,but it is a poor solution for the management of the evidence conflict at the normalization step.When deal with high conflict infor...The classical Dempster's combination rule is the most popular rule of combinations,but it is a poor solution for the management of the evidence conflict at the normalization step.When deal with high conflict information it can even involve counter-intuitive results.Based on evidence distance,some inherent characters of evidences are extracted,and discount method to combine conflicting evidence was proposed.The discount method can be also used to fuse image sequences to recognize targets.Examples show that the proposed method can provide reasonable results with good convergence efficiency.展开更多
文摘One of the most important responsibilities of a supply chain manager is to decide “how much” (or “many”) of inventory items to order and how to transport them. This paper presents four mixed-integer linear programming models to help supply chain managers make these decisions for multiple products subject to multiple constraints when suppliers offer quantity discounts and shippers offer freight discounts. Each model deals with one of the possible combinations of all-units, incremental quantity discounts, all-weight and incremental freight discounts. The models are based on a piecewise linear approximation of the number of orders function. They allow any number of linear constraints and determine if independent or common (fixed) cycle ordering has a lower total cost. Results of computational experiments on an example problem are also presented.
文摘In this present paper, a deterministic lot size model is developed for deteriorating items with incremental quantity discounts. It is assumed that shortages are permitted to occur and fully backlogged. A simple solution procedure is shown for determining the optimal order lot size and the optimal order cycle. A numerical example is used to illustrate how the solution procedure works.
基金Acknowledgments This paper is supported by the National Social Science Foundation of China (No. 10CJY007) and the Southwestern University of Finance and Economics (2010XG072). We greatly appreciate the extensive assistance from Katherine Ye, Xiaoqin Qi, and Yichen Deng.
文摘Private placement has become an increasingly important method of equity refinancing for regulators, listed companies, and investors. This paper analyzes factors influencing private placement discounts based on the controlling shareholder's opportunistic behavior and information asymmetry. Our findings indicate that the type of subscriber is a key determinant of the private placement discount, particularly when the subscriber is the controlling shareholder. Asymmetric information between listed companies and investors is another important determinant: The higher the degree of information asymmetry, the greater the private placement discounts.
基金Supported by the Natural Science Foundation of Gansu Province,No.22JR5RN1054.
文摘BACKGROUND The role of physical activity in diabetes is critical,influencing this disease's development,man-agement,and overall outcomes.In China,22.3%of adults do not meet the minimum level of physical activity recommended by the World Health Organization.Therefore,it is imperative to identify the factors that contributing to lack of physical activity must be identified.AIM To investigate the relationship among delay discounting,delay aversion,glycated hemoglobin(HbA1c),and various levels of physical activity in Chinese adults diagnosed with type 2 diabetes mellitus(T2DM).METHODS In 2023,400 adults with T2DM were recruited from the People's Hospital of Linxia Hui Autonomous Prefecture of Gansu Province.A face-to-face questionnaire was used to gather demographic data and details on physical activity,delay discounting,and delay aversion.In addition,HbA1c levels were measured in all 400 participants.The primary independent variables considered were delay discounting and delay aversion.The outcome variables included HbA1c levels and different intensity levels of physical activity,including walking,moderate physical activity,and vigorous physical activity.Multiple linear regression models were utilized to assess the relationship between delay discounting,delay aversion,and HbA1c levels,along with the intensity of different physical activity measured in met-hours per week.RESULTS After controlling for the sample characteristics,delay discounting was negatively associated with moderate physical activity(β=-2.386,95%CI:-4.370 to-0.401).Meanwhile,delay aversion was negatively associated with the level of moderate physical activity(β=-3.527,95%CI:-5.578 to-1.476)in the multiple linear regression model,with statistically significant differences.CONCLUSION Elevated delay discounting and increased delay aversion correlated with reduced levels of moderate physical activity.Result suggests that delay discounting and aversion may influence engagement in moderate physical activity.This study recommends that health administration and government consider delay discounting and delay aversion when formulating behavioral intervention strategies and treatment guidelines involving physical activity for patients with T2DM,which may increase participation in physical activity.This study contributes a novel perspective to the research on physical activity in adults with T2DM by examining the significance of future health considerations and the role of emotional responses to delays.
基金The Achievements of Young Fund Project of Humanitiesand Social Science of Ministry of Education(No.07JC790028)the NationalNatural Science Foundation of China (No.70671025).
文摘The polynomial spline model, which belongs to the static term structure model of interest rates, is studied. Every cash flow of the project is discounted relatively accurately by obtaining the discount rate from the static term structure model of interest rates. A simple basic model, which belongs to the dynamic term structure model, is studied, and the option pricing formula under changing risk-free rates is obtained by bringing it into the option pricing formula. Both dynamic and static term structure models are estimated by the use of the data of buy-back rates and the Shanghai Stock Exchange, and an example is given to compare the differences between the traditional method and the method under the changes in the interest rates and the discount rates.
文摘With Internet changing the luxury business landscape,new players have emerged such as the Online Private Sales Retailers(OPSRs).These offer online buyers with a choice of limited-time sales to help companies get rid of their overstocks.Luxury brands are no exception.No research has been conducted about how luxury consumers relate with such websites,hence this paper.In an exploratory fashion,interviews with luxury buyers who also buy online on OPSRs,are conducted to get insights on consumers’perceptions and luxury brand equity that selling through OPSRs may have.We find that appropriate product and brand help consumers forget that they are buying brands’unsold stocks,that transferring the luxury webmospheres would be positively perceived,that consumers from these websites are looking for benefits such as freedom of use and brand discovery,rather than personalized offers,that multiple discounts on several OPSRs may damage the luxury-perception of a brand,that the private sales members consider the service to be good enough for the demanded price,and that personalized invitations can help increase online consumers’feelings of desirability and exclusivity.The paper concludes with practical recommendations for both luxury companies and OPSRs.
基金The National Natural Science Foundation of China(No.70771026)
文摘The development and deployment of privary preserving supply chain quantity discount contract design can allow supply chain collaborations to take place without revealing any participant's data to others, reaping the benefits of collaborations wbile avoiding the drawbacks of privacy information disclosure. First, secure multi-party computation protocols are applied in the joint-ordering policy between a single supplier and a single retailer, the joint-ordering policy can be conducted without disclosing private cost information of any of the other supply chain partners. Secondly, secure multi-party computation protocols are applied in the privacy preserving supply chain quantity discount contract design between a single supplier and a single retailer. The information disclosure analyses of the algorithm show that: the optimal quantity discount of the jointordering policy can be conducted without disclosing private cost information of any of the other supply chain partners; the above protocol can be implemented without mediators; the privacy preserving quantity discount algorithm can be mutually verifiable and has solved the problem of asymmetric information.
文摘Objective: Lung cancer is one of the leading cancers and major causes of cancer mortality worldwide. The economic burden associated with the high mortality of lung cancer is high, which accounts for nearly $180 billion on a global scale in 2008. This paper aims to understand the economic burden of lung cancer in terms of disability adjusted life years(DALY) in Australia, the Philippines, and Singapore.Methods: The years of life lost(YLL) and years lost due to disability(YLD) were calculated using the formula developed by Murray and Lopez in 1996 as part of a comprehensive assessment of mortality and disability for diseases, injuries and risk factors in 1990 and projected to 2020. The same formula is represented in the Global Burden of Disease template provided by the World Health Organization. Appropriate assumptions were made when data were unavailable and projections were performed using regression analysis to obtain data for 2015.Results: The total DALYs due to lung cancer in Australia, the Philippines, and Singapore were 91,695, 38,584, and 12,435,respectively, and the corresponding DALY rates per a population of 1,000 were 4.0, 0.4, and 2.2, respectively, with a discount rate of 3%. When researchers calculated DALYs without the discount rate, the burden of disease increased substantially; the DALYs were 117,438 in Australia, 50,977 in the Philippines, and 16,379 in Singapore. Overall, YLL or premature death accounted for more than 95% of DALYs in these countries.Conclusions: Strategies for prevention, early diagnosis, and prompt treatment must be devised for diseases where the major burden is due to mortality.
基金Surported by the Third Stage of 211 ProjectInnovative Talent Training Project of S-09110the Chongqing University Postgraduates’ Science and Innovation Fund (200911B1B0110327)
文摘In this paper, a compound Poisson risk model with time-dependent claims is studiedunder a multi-layer dividend strategy. A piecewise integro-differential equation for the Gerber- Shiu function is derived and solved. Asymptotic formulas of the ruin probability are obtained when the claim size distributions are heavy-tailed.
文摘We consider that the reserve of an insurance company follows a renewal risk process with interest and dividend. For this risk process, we derive integral equations and exact infinite series expressions for the Cerber-Shiu discounted penalty function. Then we give lower and upper bounds for the ruin probability. Finally, we present exact expressions for the ruin probability in a special case of renewal risk processes.
基金supported by the Special Fund for Agro-Scientific Research in the Public Interest, China (2009030012-3)
文摘Salinity is one of the major abiotic factors affecting the growth and productivity of crops in Hetao Irrigation District, China. In this study, the salinity tolerances of three local crops, wheat (Triticum aestinum L.), maize (Zea mays L.) and sunflower (Helianthus annuus L.), growing in 76 farm fields are evaluated with modified discount function. Salinity ecological zones appropriate for these local crops are characterized and a case study is presented for crop salinity ecological zoning. The results show that the yield reductions of wheat, maize and sunflower when grown in saline soils are attributed primarily to a reduction in spikelet number, 1 000-grain weight and seed number per head, respectively. Sunflower is the most tolerant crop among the three which had a salinity tolerance index (ST-index) of 12.24, followed by spring maize and spring wheat with ST-Indices of 9.00 and 7.43, respectively. According to the crop salinity tolerance results, the arable land in the Heping Village of this district was subdivided into four salinity ecological zones: the most suitable, suitable, sub-suitable and unsuitable zones. The area proportion of the most suitable zone for wheat, maize and sunflower within the Heping Village was 27.5, 46.5 and 77.5%, respectively. Most of the most suitable zone occurred in the western part of the village. The results of this study provide the scientific basis for optimizing the local major crop distribution and improving cultural practices management in Hetao Irrigation District.
文摘The overseas oil and gas investment evaluation is one of the core tasks in overseas investment of oil and gas companies,among which risk evaluation and benefit evaluation are the most important.This paper sets forth transmission paths of risk factors to the investment benefit by identifying 14 overseas oil and gas investment risks in four categories.On the basis of the concept of risk compensation,different compensation mechanisms specific to each risk are designed.The risk and benefit are integrated objectively to develop a comprehensive evaluation model by correcting the recoverable reserve,adjusting benefit evaluation parameters such as investments on exploration and development,and compensating for the changes in risk factors with time through dynamic discount rate.Moreover,two cases studies,namely the evaluations of Project A in Sudan and comparison among Blocks A–G,are used to describe usage method and applicable scope of such evaluation model,respectively.According to the results,oil price is a key influencing factor for enterprise internal risk and industrial risk.Risk compensation reduces comprehensive benefit of overseas oil and gas investment and undermines the investment feasibility and priority of blocks.The research findings of this paper are free from the effects of some subject factors and avoid multi-objective decision making,and also avoid the undesired repeated calculation of risk factors.
基金supported by the National Natural Science Foundation of China(71571190 71601183+1 种基金 L1534031)the Shanxi Province Natural Science Foundation of China(2014JQ2-7045)
文摘In order to achieve the information fusion in the time domain based on the evidence theory, an evidence combination method in the time domain based on reliability and importance is proposed according to the idea of evidence discount. Firstly, the distortion of the time-domain evidence is judged based on single exponential smoothing. The real-time reliability of the evidence at the adjacent time is obtained by the real-time reliability assessment method of the evidence based on the credibility decay model.Then, the relative importance of the evidence at the adjacent time is obtained by comprehensively considering improved conflict degree and uncertainty. Finally, based on the criterion of evidence discount and the Dempster’s rule of combination, the evidence combination is carried out to achieve the sequential combination of time-domain evidence. The numerical simulation and analysis show that this method has fully embodied the dynamic characteristics of time-domain evidence combination, and it has strong processing ability for conflict information and anti-disturbing ability.The proposed method has good applicability to information fusion in the time domain.
基金supported by the National Natural science Foundation of china(70271069)
文摘The purpose of this paper is to consider the expected value of a discounted penalty due at ruin in the Erlang(2) risk process under constant interest force. An integro-differential equation satisfied by the expected value and a second-order differential equation for the Laplace transform of the expected value are derived. In addition, the paper will present the recursive algorithm for the joint distribution of the surplus immediately before ruin and the deficit at ruin. Finally, by the differential equation, the defective renewal equation and the explicit expression for the expected value are given in the interest-free case.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.71871171,71871173,and 71701076)
文摘The emergence of cooperation still remains a fundamental conundrum in the social and behavior sciences.We introduce a new mechanism,deposit mechanism,into theoretical model to explore how this mechanism promotes cooperation in a well-mixed population.Firstly,we extend the common binary-strategy combination of cooperation and defection in public good game by adding a third strategy,namely,deposit cooperation.The players with deposit cooperation strategy pay a deposit in advance to obtain the benefits of public good at a lower contributions compared with the players with cooperation strategy,when the provision of public good is successful.Then,we explore the evolution of cooperation in the public good game with deposit by means of the replicator dynamics.Theoretical computations and stimulations show that the deposit mechanism can promote cooperation in a well-mixed population,and the numbers of equilibrium point are determined by variables of public good game.On the one hand,when the coexistence of cooperators and defectors is the stable equilibrium point in the evolutionary system,increasing the threshold of public good and adopting the weak altruism way for share benefits can enhance the level of cooperation in the population.On the other hand,if the coexistence of deposit cooperators and defectors is the stable equilibrium point,it is effective to promote the deposit cooperation by lowering the values of discount and deposit,and raising the threshold of public good.
基金supported by the National Natural Science Foundation of China (717712167170120972001214)。
文摘In the world, most of the successes are results of longterm efforts. The reward of success is extremely high, but before that, a long-term investment process is required. People who are “myopic” only value short-term rewards and are unwilling to make early-stage investments, so they hardly get the ultimate success and the corresponding high rewards. Similarly, for a reinforcement learning(RL) model with long-delay rewards, the discount rate determines the strength of agent’s “farsightedness”.In order to enable the trained agent to make a chain of correct choices and succeed finally, the feasible region of the discount rate is obtained through mathematical derivation in this paper firstly. It satisfies the “farsightedness” requirement of agent. Afterwards, in order to avoid the complicated problem of solving implicit equations in the process of choosing feasible solutions,a simple method is explored and verified by theoreti cal demonstration and mathematical experiments. Then, a series of RL experiments are designed and implemented to verify the validity of theory. Finally, the model is extended from the finite process to the infinite process. The validity of the extended model is verified by theories and experiments. The whole research not only reveals the significance of the discount rate, but also provides a theoretical basis as well as a practical method for the choice of discount rate in future researches.
基金Supported in part by the National Natural Science Foun-dation of China and the Ministry of Education of China
文摘In this article, we consider an optimal proportional reinsurance with constant dividend barrier. First, we derive the Hamilton-Jacobi-Bellman equation satisfied by the expected discounted dividend payment, and then get the optimal stochastic control and the optimal constant barrier. Secondly, under the optimal constant dividend barrier strategy, we consider the moments of the discounted dividend payment and their explicit expressions are given. Finally, we discuss the Laplace transform of the time of ruin and its explicit expression is also given.
基金support for a three-year project funded by the ARC(Australian Research Council funding scheme DP170101227)with which first author’s visiting fellowship was provided for his visit to UoW between Jan 2019 and Dec 2019+1 种基金support provided by the National Natural Science Foundation of China(No.12101554)the Fundamental Research Funds for Zhejiang Provincial Universities(No.GB202103001).
文摘This article addresses the problem of pricing European options when the underlying asset is not perfectly liquid.A liquidity discounting factor as a function of market-wide liquidity governed by a mean-reverting stochastic process and the sensitivity of the underlying price to market-wide liquidity is firstly introduced,so that the impact of liquidity on the underlying asset can be captured by the option pricing model.The characteristic function is analytically worked out using the Feynman–Kac theorem and a closed-form pricing formula for European options is successfully derived thereafter.Through numerical experiments,the accuracy of the newly derived formula is verified,and the significance of incorporating liquidity risk into option pricing is demonstrated.
基金National Defense Key Laboratory Foundation(No.51476040103JW13);The National Natural Science Foundation of China(No.30400067)
文摘The classical Dempster's combination rule is the most popular rule of combinations,but it is a poor solution for the management of the evidence conflict at the normalization step.When deal with high conflict information it can even involve counter-intuitive results.Based on evidence distance,some inherent characters of evidences are extracted,and discount method to combine conflicting evidence was proposed.The discount method can be also used to fuse image sequences to recognize targets.Examples show that the proposed method can provide reasonable results with good convergence efficiency.