基于改进局部搜索策略的人工蜂群算法

针对人工蜂群算法在函数优化问题求解过程中容易陷入局部最优,收敛速度慢的缺点,提出了一种基于改进局部搜索策略的人工蜂群算法。该算法中跟随蜂采用基于当前最优解的混沌局部搜索策略,侦查蜂采用基于当前最优解的自适应侦查策略,并使其局部搜索范围随着迭代次数的增加逐渐减小,从而提高了人工蜂群算法的局部搜索能力,有效地避免了其陷入局部最优。6个测试函数的仿真实验结果表明,与传统的人工蜂群算法相比,改进后算法的求解精度和收敛速度明显提升。     

基于当前最优解的分段搜索策略的人工蜂群算法

为了克服人工蜂群算法在求解函数优化问题中所存在的局部搜索能力差、收敛精度低的缺点,提出了一种基于当前最优解的分段搜索策略的人工蜂群算法。该算法中跟随蜂利用由全局当前最优解和个体当前最优解引导的局部搜索策略逐维进行变异,并采用基于“分段思想”的局部搜索策略对蜜源进行贪婪更新,以提高蜜源的更新效率,从而提高了人工蜂群算法的局部搜索能力。6个标准测试函数的仿真实验结果表明,与基本人工蜂群算法相比,改进后的人工蜂群算法在寻优精度和收敛速度上均有明显提高。     

基于细菌趋药性和当前最优解策略的人工蜂群算法

为了克服人工蜂群算法在求解函数优化问题中所存在的收敛精度低、收敛速度慢的缺点,提出一种基于细菌趋药性和当前最优解策略的人工蜂群算法。该算法将细菌觅食优化算法中的趋向性操作引入到雇佣蜂的局部搜索策略中,然后跟随蜂在当前最优解的基础上继续进行寻优,从而提高了人工蜂群算法的局部搜索能力。8个标准测试函数的仿真实验结果表明,与基本人工蜂群算法相比,改进后的人工蜂群算法在寻优精度和收敛速度上均有明显提高。     

供应商一级密封报价博弈模型研究

在一个复杂的供应链系统中,由于供应商之间信息保密,那么供应商之间将会出现不完全信息竞争博弈。基于一级密封拍卖方式与供应链中供应商的投标报价的相似性,利用一级密封拍卖模型对供应商的竞争报价进行了研究,建立了供应商报价博弈模型,得到供应商的最优报价策略,定量地解决了报价中的信息不完全的问题,为供应商的报价决策提供参考。     

基于多策略融合的改进人工蜂群算法

针对标准人工蜂群算法存在易陷入局部最优、收敛速度慢等缺陷,提出一种基于多策略融合的改进人工蜂群算法。为了避免陷入局部最优,引入可调压排序选择策略,以保证种群的多样性;同时,通过跟随蜂阶段将线性调整全局引导策略、自适应动态调整因子策略与标准人工蜂群算法的更新策略组成一个动态调整策略集,通过比较食物源的当前质量值与上次迭代质量值对动态策略进行调整,以加快算法的收敛速度。利用标准测试函数进行实验仿真,结果表明该算法不仅提高了求解精度,而且加快了收敛速度,迭代次数明显减少。     

基于最优个体指导单纯形法改进的人工蜂群算法及应用

针对基本人工蜂群算法在求解复杂优化问题时,存在收敛精度低、收敛速度慢的缺点,提出一种基于最优个体指导单纯形法改进的人工蜂群算法。算法引入基于当前最优个体作为指导的单纯形法进行邻域搜索,以增强局部探索能力。同时采取保优策略,以加快收敛速度。通过6个标准测试优化问题的仿真实验表明,该算法较基本人工蜂群算法具有更高的求解精度和更快的收敛速度。将算法用于分数阶登革病毒传播模型的参数优化,所得的参数对应的模型输出与实际数据拟合情况较好。     

人工蜂群算法优化SVR的预测模型

针对人工蜂群算法存在的易陷入局部最优、收敛速度慢的缺点,引入当前最优食物源和惯性权重函数,对该算法的食物源更新方式进行改进;针对支持向量回归机的参数优化问题,将其转化为组合优化问题,并使用改进的人工蜂群算法进行优化求解,进而得到人工蜂群算法优化SVR的预测模型。以短期交通流量数据为例,将该模型的预测结果与蚁群算法优化的支持向量回归机（ACO-SVR）、粒子群算法优化的支持向量回归机（PSO-SVR）和未改进的蜂群算法优化的支持向量回归机（ABC-SVR）进行对比分析,结果表明该模型的预测效果最优且运行时间最短,具有更好的学习能力和推广能力。     

求解函数优化问题的改进人工蜂群算法

标准人工蜂群算法由于局部搜索能力差,收敛精度低,容易陷入早熟收敛等缺陷,从而求解最小值函数优化问题的能力受到限制。为了解决标准人工蜂群算法的以上问题,提出了一种改进的人工蜂群算法。该算法将混沌算子引入雇佣蜂和跟随蜂基于当前最优解的局部搜索策略中,并赋予跟随蜂细菌的趋药性,从而
　　提高了人工蜂群算法的局部搜索能力。在6个测试函数上的仿真结果表明,该算法能有效地避免陷入局部最优,并使收敛精度得到显著提高。     

基于组合拍卖机制的移动Agent投标策略

针对Agent系统资源分配需求提出一种兼顾Agent时间片数量要求和执行截止期限要求的投标策略。定义CPU时间片组合拍卖问题模型,设计Agent各种投标信息处理方法,包括适合组合拍卖CPU时间片机制的Agent零智能投标算法和NZIPca投标算法。仿真结果表明NZIPca策略具有较强的竞标能力。     

基于学习型人工蜂群算法优化双向GRU的乙烯产率预测

本文针对以乙烯产率为生产指标的预测问题, 基于双向门控循环单元网络(BGRU)建立乙烯产率预测模型,以最小化模型误差为优化目标并提出一种学习型人工蜂群算法 (LABC) 对预测模型进行优化和设计. 在构建BGRU预测模型时, 先对乙烯裂解炉实际生产过程进行分析, 确定影响产率的关键因素并将其作为模型的输入; 再采用LABC对BGRU网络模型的结构、初始权值和阈值、训练比和动量因子进行全面的优化和设计. 在LABC中, 首先根据人工蜂群算法(ABC)特点构建强化学习(RL)框架下的状态集、动作集、奖励函数和最优混合搜索策略, 在此基础上, 提出一种深度双Q网络(DDQN) 来实现最优混合搜索策略, 通过该策略可智能选择合适的搜索动作来执行针对不同状态的局部搜索. 本文通过在标准数据集和实际生产数据上的测试及算法对比, 验证了所提学习型人工蜂群算法优化的双向GRU 网络(LABC BGRU)模型具有预测精度高、适用性强的特性.     

Performance Evaluation of Multi-Object Auctions

The paper evaluates the performance of two multi-object auction models: sequential and simultaneous, using different performance measures. The objects put up for auction have different synergies for different bidders. We define different types of bidders who can exist in these multi-object auction models. The classification of bidders is based on the bidding strategies they use. We then study the effects of different parameters in auction and bidding strategies, on the performance of these auction models by simulating them using a JAVA based framework.This material is based upon work supported by a National Science Foundation grant (DMI 9800449) to the Dharmaraj Veeramani last author. The authors also thank the referees of the paper and the area editors for their valuable comments on the work.     

基于多Agent的多属性拍卖系统研究

通过对现有网上拍卖系统的深入分析,指出多属性网上拍卖系统的研究是最为薄弱的环节。依据网上交易的需求和分布式人工智能迅速发展,提出了一种基于多Agent的多属性网上拍卖系统,着重对多属性拍卖协议和策略,以及系统构架进行了探讨,给出了集成式的多属性网上拍卖系统的算法,并对今后的研究方向进行了展望。     

Optimal reserve prices in weighted GSP auctions

Most search engines use the weighted Generalized Second Price (wGSP) auction to sell keyword-based text ads, generating billions of dollars of advertising revenue every year. Designing and implementing near-optimal reserve prices for these wGSP auctions are naturally important problems for both academia and industry.In this paper, we show how to calculate and implement the near-optimal reserve price of the wGSP mechanism in realistic settings. Unlike reserve prices in standard single-item auctions, optimal reserve prices in wGSP auctions are discriminatory, different even for advertisers bidding on the same keyword. The optimal reserve price results can be extended to support CPA/CPC/CPM¹ hybrid auctions.Our simulations indicate that setting a proper reserve price will transfer some bidder utility (payoff) to auctioneer utility, resulting in higher revenue for the search engine. We describe a practical methodology to implement optimal reserve prices in production systems.     

网上逆向拍卖系统vAuc的设计与实现

vAuc系统是为日本一会社开发的基于Internet环境下的逆向拍卖系统。介绍了逆向拍卖的基本思想,详细叙述了vAuc系统的设计过程,并给出了vAuc系统的几个关键的实现技术。     

一个利用群签名的电子拍卖协议

利用群签名与可验证的秘密共享方案设计了一个新的密封投标的电子拍卖协议。在该协议中,多个拍卖者共同主持拍卖过程,所有的拍卖者通过可验证的秘密共享方案共享一个密钥,这使得投标者在投标时只需要一次加密,其计算量与拍卖者的数量无关;另外,中标者的身份是由群管理者根据中标者对投标消息的签名来确定的,所以一次注册后,投标者可同时参加多个拍卖活动,而不会泄露自己的身份。     

基于代理竞拍网站的同步竞拍技术研究与实现

网络竞拍作为电子商务的一种交易形式,已经发展得十分成熟。人们不再局限于参与本国的网络竞拍,而是越来越多地通过网络参与各国知名竞拍网站的竞拍。由于种种原因,导致跨国度竞拍难以实现,于是出现了代理竞拍网站,而同步竞拍技术是实现代理竞拍网站的核心。提出一种解决问题的网络模型,使用HttpClient抓取竞拍网站页面的数据,保证信息的实时性、减少系统数据库的开销;通过修改优化Web应用测试工具Selenium,服务器端低开销地自动完成在目标竞拍网站出价的操作,从而实现同步竞拍。该模型具有更好的兼容性、通用性和稳定性。     

Bidding strategies in online single-unit auctions: Their impact and satisfaction

Online bidders use different strategies in their biddings. However, we are unsure of the bidders strategies and their effectiveness in achieving auction goals. Our study was an attempt to identify bidding strategies empirically in online single-unit auctions and evaluate their outcome in terms of cost saving, perceived bidder enjoyment, and bidder satisfaction. A research model was developed and used to examine the relationships. Both objective and subjective data of online single-unit auctions were collected from Taobao.com to validate our postulated hypotheses. We found three main bidding strategies: early, snipe, and agent-supported ratchet bidding based on their behavior patterns. These resulted in different levels of winning outcome and cost saving, but had no significant effect on perceived enjoyment. The hypotheses of the relationship between auction outcomes and bidder satisfaction of their bidding strategies were confirmed.     

Efficient anonymous auction protocols with freewheeling bids

The need for electronic auction services has been increasing in recent years. Taking security into account, anonymity of online bidders becomes more important than it used to be. However, bidders cannot bid of his/her free will in existing anonymous auction protocols. For real-time applications, time delays are the significant factor taken into account. As a result, the proposed paper presents a simple and efficient method to ensure that the bidders can bid arbitrarily and anonymously.     

Walrasian Equilibrium: Hardness,Approximations and Tractable Instances

We study the complexity issues for Walrasian equilibrium in a special case of combinatorial auction, called single-minded auction, in which every participant is interested in only one subset of commodities. Chen et al. (J. Comput. Syst. Sci. 69(4): 675–687, 2004) showed that it is NP-hard to decide the existence of a Walrasian equilibrium for a single-minded auction and proposed a notion of approximate Walrasian equilibrium called relaxed Walrasian equilibrium. We show that every single-minded auction has a relaxed Walrasian equilibrium that satisfies at least two-thirds of the participants, proving a conjecture posed in Chen et al. (J. Comput. Syst. Sci. 69(4): 675–687, 2004). Motivated by practical considerations, we introduce another concept of approximate Walrasian equilibrium called weak Walrasian equilibrium. We show NP-completeness and hardness of approximation results for weak Walrasian equilibria. In search of positive results, we restrict our attention to the tollbooth problem (Guruswami et al. in Proceedings of the Symposium on Discrete Algorithms (SODA), pp. 1164–1173, 2005), where every participant is interested in a single path in some underlying graph. We give a polynomial time algorithm to determine the existence of a Walrasian equilibrium and compute one (if it exists), when the graph is a tree. However, the problem is still NP-hard for general graphs.