基于网络环境的若干组合优化博弈问题研究

随着互联网技术的飞速发展和社交网络的广泛普及,大量现实问题可以模型化为基于网络环境的组合优化问题,受到学术界和工业界的广泛关注。在这一过程中,参与者通常受到个人利益的驱动,采取策略性行动以实现自身效用的最大化。这种以“自利”为核心的行为模式,不仅对其他参与者产生影响,同时所有参与者的策略选择共同决定了社会福利整体目标的实现。在此背景下,参与者之间的互动呈现出合作与竞争并存的复杂局面,构成了组合优化博弈问题。本文旨在深入分析基于网络环境的三类具有挑战性的组合优化博弈问题:网络上的公共品博弈、网络上的点覆盖博弈以及网络上的路由博弈。这三类问题不仅在组合优化和理论计算机科学领域占据着举足轻重的地位,而且在管理科学与工程、经济学等多个交叉学科领域中也展现出广泛的应用前景。因此,本文将系统性地介绍这三类组合优化博弈问题,并对其最新的研究进展进行详细的梳理和深入的凝练,以期为相关领域的研究者和实践者提供有价值的参考和启示。

Mapping a stable adult-plant stripe rust resistance QTL on chromosome 6AL in Chinese wheat landrace Yibinzhuermai

Stripe rust,caused by Puccinia striiformis f.sp.tritici(Pst),is one of the most important diseases threatening the yield and stability of wheat production in China and many other countries.Identification and utilization of new genes for durable stripe rust resistance are important for ongoing control of this disease.The objectives of this study were to identify quantitative trait loci(QTL)associated with adult-plant stripe rust resistance in the Chinese wheat landrace Yibinzhuermai(YBZR)and to provide wheat breeders with new sources of potentially durable resistance.A total of 117 recombinant inbred lines(RILs)(F5:8)derived from a cross between YBZR and highly susceptible cultivar Taichung 29(TC29)were assessed for stripe rust severity in field experiments at Wenjiang in 2016 and 2017 and Chongzhou in 2016,2017,2018,and 2019 in Sichuan following inoculation with a mixture of current Pst races.The RILs were genotyped using the Wheat55K single nucleotide polymorphism(SNP)array.Three QTL were identified on chromosome arms 6AL,5BL and 7DS.QYr.YBZR-6AL and QYr.YBZR-7DS conferred major effects in all field environments,explaining 10.6%to 14.7%and 11.5%to 21.2%of phenotypic variation,respectively.The QTL on 5BL and 7DS likely correspond to previously known QTL,whereas QYr.YBZR-6AL is probably novel.Haplotype analysis revealed that the resistance allele at QYr.YBZR-6AL was present in 2.8%of 324 Chinese wheat landraces.SNP markers closely linked with QYr.YBZR-6AL were converted to kompetitive allele-specific PCR markers and validated in the RIL population and a subset of 92 wheat cultivars.QYr.YBZR-6AL and its markers should be useful in breeding programs to improve the level and durability of stripe rust resistance.

数字经济中的算法均衡挑战

在当今蓬勃发展的数字经济背景下,人类认知所带来的挑战正在重新定义经济学、运筹管理以及计算理论的新发展方向,呈现出引人注目的全新研究内容。与此同时,算法博弈论的迅猛发展,将计算因素与人的有限理性巧妙结合起来,为研究数字经济环境下的各类博弈场景提供了一个统一而简洁的方法框架,为经济学和博弈论带来了新的研究视角。本文回顾了数字经济不同情境下涌现出的各类经济均衡解的新概念,聚焦于参与者的策略行为对均衡结果的挑战与影响,运用算法博弈论对参与者策略行为进行激励分析,刻画博弈过程中参与者之间的竞争与合作关系,并评估不同策略行为对系统均衡的影响。

Design, Synthesis and Ring-Opening Properties of a New Bipyridine Fused Rhodamine-Like Chelating Ligand and the Related Transition Metal Complexes

A new bipyridine fused rhodamine-like chelating ligand and the corresponding transition metal complexes of platinum(Ⅱ)and iridi-um(Ⅲ)have been designed,synthesized and structurally characterized by X-ray crystallography.Their photophysical properties and acid-or metal ion-promoted spirocarbon ring-opening properties have been investigated.The platinum(Ⅱ)and iridium(Ⅲ)complexes show a drastic color change in solution with Hg^(2+) ions and emergency of an absorption band at around 450-600 nm,assignable to the absorption band of the ring-opened rhodamine-like ligand.The platinum(Ⅱ)complex was suggested to undergo dissociation with Hg^(2+) ion,based on the corresponding absorption titration study.Emission titration studies of iridium(Ⅲ)complexes were found to suffer from the quenching process,probably due to the presence of a lower-lying non-emissive excited state from the ring-opened form of ligand.

A Hashing Power Allocation Game with and without Risk-free Asset

Miners in various blockchain-backed cryptocurrency networks compete to maintain the validity of the underlying distributed ledgers to earn the bootstrapped cryptocurrencies.With limited hashing power,each miner needs to decide how to allocate their resource to different cryptocurrencies so as to achieve the best overall payoff.Together all the miners form a hashing power allocation game.We consider two settings of the game,depending on whether each miner can allocate their fund to a risk-free asset or not.We show that this game admits unique pure Nash equilibrium in closed-form for both settings.

The Evolutionary Equilibrium of Block Withholding Attack

Bitcoin is the most famous and the most used cryptocurrency in the world,such that it has received extreme popularity in recent years.However the Bitcoin system is accompanied by different attacks,including the block withholding(BWH)attack.When a miner plays the BWH attack,it will withhold all the blocks newly discovered in the attack pool,damaging the honest miners’right to obtain the fair reward.In this paper,we consider a setting in which two miners may honestly mine or perform the BWH attack in a mining pool.Different strategy profiles will bring different payoffs,in addition influence the selection of the strategies.Therefore,we establish an evolutionary game model to study the behavior tendency of the miners and the evolutionary stable strategies under different conditions,by formulating the replicator dynamic equations.Through numerical simulations,we further verify the theoretical results on evolutionary stable solutions and discuss the impact of the factors on miners’strategic choice.Based on these simulation results,we also make some recommendations for the manager and the miners to mitigate the BWH attack and to promote the cooperation between miners in a mining pool.