Traditional blockchain key management schemes store private keys in the same location,which can easily lead to security issues such as a single point of failure.Therefore,decentralized threshold key management schemes...Traditional blockchain key management schemes store private keys in the same location,which can easily lead to security issues such as a single point of failure.Therefore,decentralized threshold key management schemes have become a research focus for blockchain private key protection.The security of private keys for blockchain user wallet is highly related to user identity authentication and digital asset security.The threshold blockchain private key management schemes based on verifiable secret sharing have made some progress,but these schemes do not consider participants’self-interested behavior,and require trusted nodes to keep private key fragments,resulting in a narrow application scope and low deployment efficiency,which cannot meet the needs of personal wallet private key escrow and recovery in public blockchains.We design a private key management scheme based on rational secret sharing that considers the self-interest of participants in secret sharing protocols,and constrains the behavior of rational participants through reasonable mechanism design,making it more suitable in distributed scenarios such as the public blockchain.The proposed scheme achieves the escrow and recovery of personal wallet private keys without the participation of trusted nodes,and simulate its implementation on smart contracts.Compared to other existing threshold wallet solutions and keymanagement schemes based on password-protected secret sharing(PPSS),the proposed scheme has a wide range of applications,verifiable private key recovery,low communication overhead,higher computational efficiency when users perform one-time multi-key escrow,no need for trusted nodes,and personal rational constraints and anti-collusion attack capabilities.展开更多
Contract is a common and effective mechanism for supply chain coordination,which has been studied extensively in recent years.For a supply chain network model,contracts can be used to coordinate it because it is too i...Contract is a common and effective mechanism for supply chain coordination,which has been studied extensively in recent years.For a supply chain network model,contracts can be used to coordinate it because it is too ideal to obtain the network equilibrium state in practical market competition.In order to achieve equilibrium,we introduce revenue sharing contract into a supply chain network equilibrium model with random demand in this paper.Then,we investigate the influence on this network equilibrium state from demand disruptions caused by unexpected emergencies.When demand disruptions happen,the supply chain network equilibrium state will be broken and change to a new one,so the decision makers need to adjust the contract parameters to achieve the new coordinated state through bargaining.Finally,a numerical example with a sudden demand increase as a result of emergent event is provided for illustrative purposes.展开更多
Production sharing contracts have been used in the development of China’s offshore petroleum resources since 1982, but the mechanism in which the fiscal terms impact project economics is complicated and not well unde...Production sharing contracts have been used in the development of China’s offshore petroleum resources since 1982, but the mechanism in which the fiscal terms impact project economics is complicated and not well understood. The purpose of this paper is to model China’s offshore production sharing contracts using a probabilistic approach. Cash flows and economic indicators are used for a typical offshore oilfield development, and meta-models are constructed to analyze the basic features of the fiscal system. Applications of the models in contract negotiation are discussed.展开更多
Assuming that oil price follows the stochastic processes of Geometric Brownian Motion (GBM) or the Mean-Reverting Process (MRP), this paper takes the net present value (NPV) as an economic index and models the P...Assuming that oil price follows the stochastic processes of Geometric Brownian Motion (GBM) or the Mean-Reverting Process (MRP), this paper takes the net present value (NPV) as an economic index and models the PSC in 11 different scenarios by changing the value of each contract element (i.e. royalty, cost oil, profit oil as well as income tax). Then the NPVs are shown in probability density graphs to investigate the effect of different elements on contract economics. The results show that under oil price uncertainty the influence of profit oil and income tax on NPV are more significant than those of royalty and cost oil, while a tax holiday could improve the contractor's financial status remarkably. Results also show that MRP is more appropriate for cases with low future oil price volatility, and GBM is best for high future oil price volatility.展开更多
To improve the performance of the supply chain with one supplier and multiple retailers under deterministic price-sensitive customer demand, an optimal strategy is proposed based on knowledge discovery. First the dece...To improve the performance of the supply chain with one supplier and multiple retailers under deterministic price-sensitive customer demand, an optimal strategy is proposed based on knowledge discovery. First the decentralized system in which the supplier and the retailers are independent, profit-maximizing participants with the supplier acting as a Stackelberg game leader is studied. Numerical examples illustrate the importance of the coordination. The conventional quantity discount mechanism needs to be modified to coordinate the supply chain, so a revenue-sharing contract is proposed to coordinate such supply chain. Lastly, a special decision under certain demand rates is studied. The pricing and replenishment policies can be decided sequentially, which yields much less loss comparing with optimal decision when the demand rates are sufficiently large.展开更多
This paper considers the two-echelon supply chain system which consists of single agricultural producers and retailers,and analyzes the impact of sharing ratio on the option ordering quantity,and retailers and produce...This paper considers the two-echelon supply chain system which consists of single agricultural producers and retailers,and analyzes the impact of sharing ratio on the option ordering quantity,and retailers and producers' expected profits.Studies have shown that in the case of decentralization,when the revenue sharing ratio is between 0 and 0.3,the option ordering quantity of farm produce is a decreasing function of the sharing ratio; when the revenue sharing ratio is between 0.3 and 1,the option ordering quantity of farm produce is an increasing function of sharing ratio; when the revenue sharing ratio is between 0.421 and 1,the agricultural producers and retailers' expected profits are an increasing function of sharing ratio.Finally,through the numerical calculation,the applicability of the conclusions is verified,to provide a reference for the supply chain management practices.展开更多
Web of Things(WoT)resources are not only numerous,but also have a wide range of applications and deployments.The centralized WoT resource sharing mechanism lacks flexibility and scalability,and hence cannot satisfy re...Web of Things(WoT)resources are not only numerous,but also have a wide range of applications and deployments.The centralized WoT resource sharing mechanism lacks flexibility and scalability,and hence cannot satisfy requirement of distributed resource sharing in large-scale environment.In response to this problem,a trusted and secure mechanism for WoT resources sharing based on context and blockchain(CWoT-Share)was proposed.Firstly,the mechanism can respond quickly to the changes of the application environment by dynamically determining resource access control rules according to the context.Then,the flexible resource charging strategies,which reduced the fees paid by the users who shared more resources and increased the fees paid by users who frequently used resources maliciously,were used to fulfill efficient sharing of WoT resources.Meanwhile,the charging strategies also achieve load balancing by dynamic selection of WoT resources.Finally,the open source blockchain platform Ethereum was used for the simulation and the simulation results show that CWoT-Share can flexibly adapt to the application environment and dynamically adjust strategies of resource access control and resource charging.展开更多
针对出行即服务(Mobility as a Service,MaaS)提供定制化的出行服务以满足游客差异化的交通需求,构建了由传统旅游供应商和MaaS平台组成的双渠道旅游出行服务链,探讨不同主导权下的集中式决策和分散式决策策略及其效益,并开展以供应商...针对出行即服务(Mobility as a Service,MaaS)提供定制化的出行服务以满足游客差异化的交通需求,构建了由传统旅游供应商和MaaS平台组成的双渠道旅游出行服务链,探讨不同主导权下的集中式决策和分散式决策策略及其效益,并开展以供应商为主导的供应链收益共享契约设计和数值分析。研究结果发现:基于MaaS的旅游供应链集中式决策下的效益大于分散式决策,且集中式决策效益是以供应商为主导的分散式决策效益的3/4。在收益共享契约协调下,供应商利润和MaaS平台利润分别为0.68和0.58,均有所提高,旅游供应链整体效益最大,实现旅游供应链完美协调。展开更多
基金the State’s Key Project of Research and Development Plan under Grant 2022YFB2701400in part by the National Natural Science Foundation of China under Grants 62272124 and 62361010+4 种基金in part by the Science and Technology Planning Project of Guizhou Province under Grant[2020]5017in part by the Research Project of Guizhou University for Talent Introduction underGrant[2020]61in part by theCultivation Project of Guizhou University under Grant[2019]56in part by the Open Fund of Key Laboratory of Advanced Manufacturing Technology,Ministry of Education under Grant GZUAMT2021KF[01]the Science and Technology Program of Guizhou Province(No.[2023]371).
文摘Traditional blockchain key management schemes store private keys in the same location,which can easily lead to security issues such as a single point of failure.Therefore,decentralized threshold key management schemes have become a research focus for blockchain private key protection.The security of private keys for blockchain user wallet is highly related to user identity authentication and digital asset security.The threshold blockchain private key management schemes based on verifiable secret sharing have made some progress,but these schemes do not consider participants’self-interested behavior,and require trusted nodes to keep private key fragments,resulting in a narrow application scope and low deployment efficiency,which cannot meet the needs of personal wallet private key escrow and recovery in public blockchains.We design a private key management scheme based on rational secret sharing that considers the self-interest of participants in secret sharing protocols,and constrains the behavior of rational participants through reasonable mechanism design,making it more suitable in distributed scenarios such as the public blockchain.The proposed scheme achieves the escrow and recovery of personal wallet private keys without the participation of trusted nodes,and simulate its implementation on smart contracts.Compared to other existing threshold wallet solutions and keymanagement schemes based on password-protected secret sharing(PPSS),the proposed scheme has a wide range of applications,verifiable private key recovery,low communication overhead,higher computational efficiency when users perform one-time multi-key escrow,no need for trusted nodes,and personal rational constraints and anti-collusion attack capabilities.
基金supported by the National Key Technology R&D Program of China (No. 2006BAH02A06)"333 Engineering"Project of Jiangsu Province
文摘Contract is a common and effective mechanism for supply chain coordination,which has been studied extensively in recent years.For a supply chain network model,contracts can be used to coordinate it because it is too ideal to obtain the network equilibrium state in practical market competition.In order to achieve equilibrium,we introduce revenue sharing contract into a supply chain network equilibrium model with random demand in this paper.Then,we investigate the influence on this network equilibrium state from demand disruptions caused by unexpected emergencies.When demand disruptions happen,the supply chain network equilibrium state will be broken and change to a new one,so the decision makers need to adjust the contract parameters to achieve the new coordinated state through bargaining.Finally,a numerical example with a sudden demand increase as a result of emergent event is provided for illustrative purposes.
文摘Production sharing contracts have been used in the development of China’s offshore petroleum resources since 1982, but the mechanism in which the fiscal terms impact project economics is complicated and not well understood. The purpose of this paper is to model China’s offshore production sharing contracts using a probabilistic approach. Cash flows and economic indicators are used for a typical offshore oilfield development, and meta-models are constructed to analyze the basic features of the fiscal system. Applications of the models in contract negotiation are discussed.
基金financial support from Key Projects of Philosophy and Social Sciences Research of Ministry of Education (09JZD0038)
文摘Assuming that oil price follows the stochastic processes of Geometric Brownian Motion (GBM) or the Mean-Reverting Process (MRP), this paper takes the net present value (NPV) as an economic index and models the PSC in 11 different scenarios by changing the value of each contract element (i.e. royalty, cost oil, profit oil as well as income tax). Then the NPVs are shown in probability density graphs to investigate the effect of different elements on contract economics. The results show that under oil price uncertainty the influence of profit oil and income tax on NPV are more significant than those of royalty and cost oil, while a tax holiday could improve the contractor's financial status remarkably. Results also show that MRP is more appropriate for cases with low future oil price volatility, and GBM is best for high future oil price volatility.
基金the National Natural Science Foundation of China (70471034)the Talent Foundation of Nanjing University of Aeronautics and Astronautics (s0670-082).
文摘To improve the performance of the supply chain with one supplier and multiple retailers under deterministic price-sensitive customer demand, an optimal strategy is proposed based on knowledge discovery. First the decentralized system in which the supplier and the retailers are independent, profit-maximizing participants with the supplier acting as a Stackelberg game leader is studied. Numerical examples illustrate the importance of the coordination. The conventional quantity discount mechanism needs to be modified to coordinate the supply chain, so a revenue-sharing contract is proposed to coordinate such supply chain. Lastly, a special decision under certain demand rates is studied. The pricing and replenishment policies can be decided sequentially, which yields much less loss comparing with optimal decision when the demand rates are sufficiently large.
基金Supported by National Natural Science Foundation of China(7093200571102055)+1 种基金Youth Fund Project of Sichuan Provincial Department of Education(13ZB003514ZA0304)
文摘This paper considers the two-echelon supply chain system which consists of single agricultural producers and retailers,and analyzes the impact of sharing ratio on the option ordering quantity,and retailers and producers' expected profits.Studies have shown that in the case of decentralization,when the revenue sharing ratio is between 0 and 0.3,the option ordering quantity of farm produce is a decreasing function of the sharing ratio; when the revenue sharing ratio is between 0.3 and 1,the option ordering quantity of farm produce is an increasing function of sharing ratio; when the revenue sharing ratio is between 0.421 and 1,the agricultural producers and retailers' expected profits are an increasing function of sharing ratio.Finally,through the numerical calculation,the applicability of the conclusions is verified,to provide a reference for the supply chain management practices.
基金This study is funded by“The National Natural Science Foundation of China(No.61972211,No.61771258)”.
文摘Web of Things(WoT)resources are not only numerous,but also have a wide range of applications and deployments.The centralized WoT resource sharing mechanism lacks flexibility and scalability,and hence cannot satisfy requirement of distributed resource sharing in large-scale environment.In response to this problem,a trusted and secure mechanism for WoT resources sharing based on context and blockchain(CWoT-Share)was proposed.Firstly,the mechanism can respond quickly to the changes of the application environment by dynamically determining resource access control rules according to the context.Then,the flexible resource charging strategies,which reduced the fees paid by the users who shared more resources and increased the fees paid by users who frequently used resources maliciously,were used to fulfill efficient sharing of WoT resources.Meanwhile,the charging strategies also achieve load balancing by dynamic selection of WoT resources.Finally,the open source blockchain platform Ethereum was used for the simulation and the simulation results show that CWoT-Share can flexibly adapt to the application environment and dynamically adjust strategies of resource access control and resource charging.
文摘针对出行即服务(Mobility as a Service,MaaS)提供定制化的出行服务以满足游客差异化的交通需求,构建了由传统旅游供应商和MaaS平台组成的双渠道旅游出行服务链,探讨不同主导权下的集中式决策和分散式决策策略及其效益,并开展以供应商为主导的供应链收益共享契约设计和数值分析。研究结果发现:基于MaaS的旅游供应链集中式决策下的效益大于分散式决策,且集中式决策效益是以供应商为主导的分散式决策效益的3/4。在收益共享契约协调下,供应商利润和MaaS平台利润分别为0.68和0.58,均有所提高,旅游供应链整体效益最大,实现旅游供应链完美协调。