Smart contracts on the Ethereum blockchain continue to revolutionize decentralized applications (dApps) by allowing for self-executing agreements. However, bad actors have continuously found ways to exploit smart cont...Smart contracts on the Ethereum blockchain continue to revolutionize decentralized applications (dApps) by allowing for self-executing agreements. However, bad actors have continuously found ways to exploit smart contracts for personal financial gain, which undermines the integrity of the Ethereum blockchain. This paper proposes a computer program called SADA (Static and Dynamic Analyzer), a novel approach to smart contract vulnerability detection using multiple Large Language Model (LLM) agents to analyze and flag suspicious Solidity code for Ethereum smart contracts. SADA not only improves upon existing vulnerability detection methods but also paves the way for more secure smart contract development practices in the rapidly evolving blockchain ecosystem.展开更多
Objective To provide effective decision making for the subsidy policies given by the government to pharmaceutical enterprises and the coordination model adopted by pharmaceutical stakeholders under the carbon emission...Objective To provide effective decision making for the subsidy policies given by the government to pharmaceutical enterprises and the coordination model adopted by pharmaceutical stakeholders under the carbon emission trading policy.Methods The Stackelberg model was used to discuss the optimal profits of each member and the whole supply chain under different decision-making models while considering the technical capacity of emission reduction and cost sharing contract.Based on this,the impact of the combined contract decisionmaking model on the technical efforts of drug manufacturers to reduce carbon emission,the profits of supply chain members and the overall profits of supply chain was investigated.Results and Conclusion Research has found that improving the research and development efforts of emission reduction technologies by pharmaceutical enterprises can increase drug sales and enhance the expected profits of pharmaceutical supply chain members.The members of the secondary pharmaceutical supply chain can achieve the optimal expected profit when reaching cooperation.Besides,when the cost sharing contract and quantity discount contract meet the constraint conditions,the combined contract decision model can perfectly coordinate the pharmaceutical supply chain,enabling supply chain members to achieve Pareto improvement and gradually reach Pareto optimum.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
A constitutive model of quasi-Newtonian fluid based on the type of flow is used in abrupt planar contraction now.The numerical results from finite element analysis are consistent with experimental data for stress patt...A constitutive model of quasi-Newtonian fluid based on the type of flow is used in abrupt planar contraction now.The numerical results from finite element analysis are consistent with experimental data for stress patterns and velocityprofiles in the flow field. The chain conformations of polymer melts are then investigated in such a planar contraction byusing the phenomenological model with internal parameters proposed by the author. That is, the shape and orientation ofpolymer chain coils are predicted and discussed in different flow regions of the contraction flow field that possess simpleshear flow, extensional flow, vortical flow, and mixed flow respectively.展开更多
Objective Patients with repaired tetralogy of Fallot(rTOF)account for the majority of cases with late onset right ventricle(RV)failure.The current surgical approach,including pulmonary valve replacement/insertion(PVR)...Objective Patients with repaired tetralogy of Fallot(rTOF)account for the majority of cases with late onset right ventricle(RV)failure.The current surgical approach,including pulmonary valve replacement/insertion(PVR),has yielded mixed results with some patients recover RV function and some do not.An innovative surgical approach was proposed to help ventricle to contract and improve RV function qualified by ejection fraction with one or more active contracting bands.Computational biomechanical modelling is a widely used method in cardiovascular study for investigation of mechanisms governing disease development,quantitative diagnostic and treatment strategies and improving surgical designs for better outcome.Muscle active contraction caused by zero-load sarcomere shortening leads to change of zero-load configurations.In lieu of experimenting using real surgery on animal or human,computational simulations(virtual surgery)were performed to test different band combination and insertion options to identify optimal surgery design and band insertion plan.Methods Cardiac magnetic resonance(CMR)data were obtained from one rTOF patient(sex:male,age:22.5 y)before pulmonary valve replacement surgery.The patient was suffering from RV dilation and dysfunction with RV end-systole volume 254.49ml and end-diastole volume 406.91 mL.A total of 15 computational RV/LV/Patch/Band combination models based on(CMR)imaging were constructed to investigate the influence of different band insertion surgery plans.These models included 5 different band insertion models combined and 3 different band contraction ratio(10%,15%and 20%band zero-stress length reduction).These models included 5 different band insertion models:Model 1 with one band at anterior to the middle of papillary muscle;Model 2 with one band at posterior to the middle of papillary muscle;Model 3 with 2 bands which are the ones from Models 1&2 combined;Model 4 with a band at the base of the papillary muscle;Model 5 with 3 bands which is a combination of Models 3&4.A pre-shrink process was performed on in-vivo begin-filling and end-systole MRI data to obtain diastole and systole zero4oad ventricle geometries.An extra 5%-8%shrinkage was applied to obtain corresponding systole zero-load geometry reflecting myocardium sarcomere shortening.The zero-load band length in systole was 10%,15%and 20%shorter than that in diastole according to their corresponding contraction ratio.The nonlinear Mooney-Rivlin model was used to describe the ventricle material properties with their material parameter values adjusted to match measured data with CMR.The band material properties were in the same scale with healthy right ventricle.The RV/LV/Band model construction and solution procedures were the same as described.Results Model 5 with band contraction ratio of 20%has the ability to improve RV ejection fraction to 41.07%,which represented a 3.61%absolute improvement,or 9.6%relative improvement using pre-PVR ejection fraction as the baseline number.The ejection fractions for Models 1-4 with band contraction ratio of 20%were 39.28%,39.47%,38.87%and 40.34%respectively.Compared to models with band contraction ratio15%and 20%,models with band contraction ratio 10%has the least ability on RV ejection fraction improvement with ejection fraction 38.28%,38.00%,38.81%,38.50%and 39.36%corresponding to Models 1-5.Conclusions This pilot work demonstrated that the band insertion surgery may have great potential to improve post-PVR RV cardiac function for patients with repaired TOF.More band contraction ratio and inserted band number may lead to better post-surgery outcome.Further investigations using in-vitro animal experiments and final patient studies are warranted.展开更多
智能合约作为区块链核心的可编程组件,承担了资产管理和复杂业务逻辑处理的功能,它们共同构成了去中心化金融(decentralized finance,DeFi)协议.然而,随着区块链的快速发展,智能合约和DeFi协议的安全问题日益凸显,吸引了大量攻击者利用...智能合约作为区块链核心的可编程组件,承担了资产管理和复杂业务逻辑处理的功能,它们共同构成了去中心化金融(decentralized finance,DeFi)协议.然而,随着区块链的快速发展,智能合约和DeFi协议的安全问题日益凸显,吸引了大量攻击者利用其漏洞牟取利益.近年来,多起涉及智能合约和DeFi协议的重大安全事件强调了漏洞检测技术研究的必要性,已成为安全防护的重中之重.系统性地总结了现有工作,提出了智能合约与DeFi协议漏洞检测技术研究框架,分别从智能合约和DeFi协议两个层面对漏洞类型和检测技术进行梳理.在智能合约方面,重点分析了大语言模型(large language model,LLM)作为主要检测引擎和与传统方法结合的漏洞检测技术应用情况;在DeFi协议方面,系统性地分类并整理了DeFi协议层的漏洞及其检测方法,并探讨了攻击发生前后检测方法的优势与局限性,弥补了现有综述在DeFi协议漏洞检测方面的不足.最后,对现有检测方法面临的挑战进行总结,并展望了未来的研究方向,旨在为智能合约与DeFi协议的安全检测提供新的思路和理论支持.展开更多
光伏储能接入铁路牵引供电系统对推动节能减排、提升系统效能具有重要意义,然而当前全国铁路沿线光储项目虽投资潜力巨大,却尚未形成成熟的商业模式。为此,本文旨在研究适用于牵引供电光储系统的合同能源管理机制及其收益分配方法,以促...光伏储能接入铁路牵引供电系统对推动节能减排、提升系统效能具有重要意义,然而当前全国铁路沿线光储项目虽投资潜力巨大,却尚未形成成熟的商业模式。为此,本文旨在研究适用于牵引供电光储系统的合同能源管理机制及其收益分配方法,以促进该领域的商业化推广。本文提出将节能效益分享型合同能源管理应用于牵引供电光储系统,明确铁路部门(railroad department,RD)与节能服务公司(energy service company,ESCo)作为核心利益相关方。ESCo负责项目投资建设与运营,并通过分享节能收益回收成本并盈利;RD则以低风险方式使用清洁电力,实现能效提升目标。在此基础上,构建基于风险系数修正的Stackelberg收益分配模型,以ESCo初始投资成本和节能效益分享比例为变量,引入风险修正因子反映双方在管理、技术及市场等方面的风险差异,从而优化收益分配的合理性与可接受性。通过对某牵引所算例进行仿真分析,验证模型的有效性。仿真结果表明,所提出的收益分配方法能够在满足RD用电经济性需求的同时,确保ESCo获得预期的投资回报,验证了该模型在实践中的可行性与有效性。此外,研究还分析了储能单元及变流器等接口设备成本变动对合同能源管理项目经济效益的敏感度,为成本优化及政策支持提供了重要参考。研究表明,基于风险修正的合同能源管理模式能够有效推动铁路牵引供电光储系统的商业化应用。未来可通过设备成本优化与政策引导,进一步提升项目的经济性与推广价值。展开更多
This paper is prepared in honour of Professor E.T.Brown for his outstanding contributions to rock mechanics and geotechnical engineering and also for his personal influence on the first author’s research career in ge...This paper is prepared in honour of Professor E.T.Brown for his outstanding contributions to rock mechanics and geotechnical engineering and also for his personal influence on the first author’s research career in geomechanics and geotechnical engineering.As a result,we have picked a topic that reflects two key research areas in which Professor E.T.Brown has made seminal contributions over a long and distinguished career.These two areas are concerned with the application of the critical state concept to modelling geomaterials and the analysis of underground excavation or tunnelling in geomaterials.Partially due to Professor Brown’s influence,the first author has also been conducting research in these two areas over many years.In particular,this paper aims to describe briefly the development of a unified critical state model for geomaterials together with an application to cavity contraction problems and tunnelling in soils.展开更多
文摘Smart contracts on the Ethereum blockchain continue to revolutionize decentralized applications (dApps) by allowing for self-executing agreements. However, bad actors have continuously found ways to exploit smart contracts for personal financial gain, which undermines the integrity of the Ethereum blockchain. This paper proposes a computer program called SADA (Static and Dynamic Analyzer), a novel approach to smart contract vulnerability detection using multiple Large Language Model (LLM) agents to analyze and flag suspicious Solidity code for Ethereum smart contracts. SADA not only improves upon existing vulnerability detection methods but also paves the way for more secure smart contract development practices in the rapidly evolving blockchain ecosystem.
文摘Objective To provide effective decision making for the subsidy policies given by the government to pharmaceutical enterprises and the coordination model adopted by pharmaceutical stakeholders under the carbon emission trading policy.Methods The Stackelberg model was used to discuss the optimal profits of each member and the whole supply chain under different decision-making models while considering the technical capacity of emission reduction and cost sharing contract.Based on this,the impact of the combined contract decisionmaking model on the technical efforts of drug manufacturers to reduce carbon emission,the profits of supply chain members and the overall profits of supply chain was investigated.Results and Conclusion Research has found that improving the research and development efforts of emission reduction technologies by pharmaceutical enterprises can increase drug sales and enhance the expected profits of pharmaceutical supply chain members.The members of the secondary pharmaceutical supply chain can achieve the optimal expected profit when reaching cooperation.Besides,when the cost sharing contract and quantity discount contract meet the constraint conditions,the combined contract decision model can perfectly coordinate the pharmaceutical supply chain,enabling supply chain members to achieve Pareto improvement and gradually reach Pareto optimum.
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This work was supported by the research grants from the National Nature Science Foundation of China (No. 20174024) and the Special Founds for Major State Basic Research Projects (G199906408)
文摘A constitutive model of quasi-Newtonian fluid based on the type of flow is used in abrupt planar contraction now.The numerical results from finite element analysis are consistent with experimental data for stress patterns and velocityprofiles in the flow field. The chain conformations of polymer melts are then investigated in such a planar contraction byusing the phenomenological model with internal parameters proposed by the author. That is, the shape and orientation ofpolymer chain coils are predicted and discussed in different flow regions of the contraction flow field that possess simpleshear flow, extensional flow, vortical flow, and mixed flow respectively.
基金supported in part by National Sciences Foundation of China grants ( 11672001, 81571691,81771844)
文摘Objective Patients with repaired tetralogy of Fallot(rTOF)account for the majority of cases with late onset right ventricle(RV)failure.The current surgical approach,including pulmonary valve replacement/insertion(PVR),has yielded mixed results with some patients recover RV function and some do not.An innovative surgical approach was proposed to help ventricle to contract and improve RV function qualified by ejection fraction with one or more active contracting bands.Computational biomechanical modelling is a widely used method in cardiovascular study for investigation of mechanisms governing disease development,quantitative diagnostic and treatment strategies and improving surgical designs for better outcome.Muscle active contraction caused by zero-load sarcomere shortening leads to change of zero-load configurations.In lieu of experimenting using real surgery on animal or human,computational simulations(virtual surgery)were performed to test different band combination and insertion options to identify optimal surgery design and band insertion plan.Methods Cardiac magnetic resonance(CMR)data were obtained from one rTOF patient(sex:male,age:22.5 y)before pulmonary valve replacement surgery.The patient was suffering from RV dilation and dysfunction with RV end-systole volume 254.49ml and end-diastole volume 406.91 mL.A total of 15 computational RV/LV/Patch/Band combination models based on(CMR)imaging were constructed to investigate the influence of different band insertion surgery plans.These models included 5 different band insertion models combined and 3 different band contraction ratio(10%,15%and 20%band zero-stress length reduction).These models included 5 different band insertion models:Model 1 with one band at anterior to the middle of papillary muscle;Model 2 with one band at posterior to the middle of papillary muscle;Model 3 with 2 bands which are the ones from Models 1&2 combined;Model 4 with a band at the base of the papillary muscle;Model 5 with 3 bands which is a combination of Models 3&4.A pre-shrink process was performed on in-vivo begin-filling and end-systole MRI data to obtain diastole and systole zero4oad ventricle geometries.An extra 5%-8%shrinkage was applied to obtain corresponding systole zero-load geometry reflecting myocardium sarcomere shortening.The zero-load band length in systole was 10%,15%and 20%shorter than that in diastole according to their corresponding contraction ratio.The nonlinear Mooney-Rivlin model was used to describe the ventricle material properties with their material parameter values adjusted to match measured data with CMR.The band material properties were in the same scale with healthy right ventricle.The RV/LV/Band model construction and solution procedures were the same as described.Results Model 5 with band contraction ratio of 20%has the ability to improve RV ejection fraction to 41.07%,which represented a 3.61%absolute improvement,or 9.6%relative improvement using pre-PVR ejection fraction as the baseline number.The ejection fractions for Models 1-4 with band contraction ratio of 20%were 39.28%,39.47%,38.87%and 40.34%respectively.Compared to models with band contraction ratio15%and 20%,models with band contraction ratio 10%has the least ability on RV ejection fraction improvement with ejection fraction 38.28%,38.00%,38.81%,38.50%and 39.36%corresponding to Models 1-5.Conclusions This pilot work demonstrated that the band insertion surgery may have great potential to improve post-PVR RV cardiac function for patients with repaired TOF.More band contraction ratio and inserted band number may lead to better post-surgery outcome.Further investigations using in-vitro animal experiments and final patient studies are warranted.
文摘智能合约作为区块链核心的可编程组件,承担了资产管理和复杂业务逻辑处理的功能,它们共同构成了去中心化金融(decentralized finance,DeFi)协议.然而,随着区块链的快速发展,智能合约和DeFi协议的安全问题日益凸显,吸引了大量攻击者利用其漏洞牟取利益.近年来,多起涉及智能合约和DeFi协议的重大安全事件强调了漏洞检测技术研究的必要性,已成为安全防护的重中之重.系统性地总结了现有工作,提出了智能合约与DeFi协议漏洞检测技术研究框架,分别从智能合约和DeFi协议两个层面对漏洞类型和检测技术进行梳理.在智能合约方面,重点分析了大语言模型(large language model,LLM)作为主要检测引擎和与传统方法结合的漏洞检测技术应用情况;在DeFi协议方面,系统性地分类并整理了DeFi协议层的漏洞及其检测方法,并探讨了攻击发生前后检测方法的优势与局限性,弥补了现有综述在DeFi协议漏洞检测方面的不足.最后,对现有检测方法面临的挑战进行总结,并展望了未来的研究方向,旨在为智能合约与DeFi协议的安全检测提供新的思路和理论支持.
文摘光伏储能接入铁路牵引供电系统对推动节能减排、提升系统效能具有重要意义,然而当前全国铁路沿线光储项目虽投资潜力巨大,却尚未形成成熟的商业模式。为此,本文旨在研究适用于牵引供电光储系统的合同能源管理机制及其收益分配方法,以促进该领域的商业化推广。本文提出将节能效益分享型合同能源管理应用于牵引供电光储系统,明确铁路部门(railroad department,RD)与节能服务公司(energy service company,ESCo)作为核心利益相关方。ESCo负责项目投资建设与运营,并通过分享节能收益回收成本并盈利;RD则以低风险方式使用清洁电力,实现能效提升目标。在此基础上,构建基于风险系数修正的Stackelberg收益分配模型,以ESCo初始投资成本和节能效益分享比例为变量,引入风险修正因子反映双方在管理、技术及市场等方面的风险差异,从而优化收益分配的合理性与可接受性。通过对某牵引所算例进行仿真分析,验证模型的有效性。仿真结果表明,所提出的收益分配方法能够在满足RD用电经济性需求的同时,确保ESCo获得预期的投资回报,验证了该模型在实践中的可行性与有效性。此外,研究还分析了储能单元及变流器等接口设备成本变动对合同能源管理项目经济效益的敏感度,为成本优化及政策支持提供了重要参考。研究表明,基于风险修正的合同能源管理模式能够有效推动铁路牵引供电光储系统的商业化应用。未来可通过设备成本优化与政策引导,进一步提升项目的经济性与推广价值。
文摘This paper is prepared in honour of Professor E.T.Brown for his outstanding contributions to rock mechanics and geotechnical engineering and also for his personal influence on the first author’s research career in geomechanics and geotechnical engineering.As a result,we have picked a topic that reflects two key research areas in which Professor E.T.Brown has made seminal contributions over a long and distinguished career.These two areas are concerned with the application of the critical state concept to modelling geomaterials and the analysis of underground excavation or tunnelling in geomaterials.Partially due to Professor Brown’s influence,the first author has also been conducting research in these two areas over many years.In particular,this paper aims to describe briefly the development of a unified critical state model for geomaterials together with an application to cavity contraction problems and tunnelling in soils.
