考虑不确定性的风-光-储合作联盟参与含需求响应的主辅联合市场的竞价交易模型

清洁能源逐渐成为电力市场的竞争主体,考虑风光出力不确定性和探究高效的市场运行机制成为电力现货市场建设进程中的关键问题。采用非参数核密度估计法和多元Gaussian-Copula函数生成典型出力场景来描述风光出力的不确定性和时空相关性。上层模型基于纳什谈判理论最大化风-光-储合作联盟收益,采用麻雀搜索算法优化风光发电商的报价策略。下层模型以购电总成本最小为目标,设计了多主体参与含价格型需求响应的主辅联合市场的出清机制。最后分析了风光出力的典型场景和市场出清结果的合理性。通过算例验证了该优化模型能够提升合作个体的收益,降低了购电总成本和负荷的峰谷差。     

旋转摩擦挤压制备MWCNTs/Al复合材料的组织及磨损性能EI北大核心CSCD

采用旋转摩擦挤压(RFE)法制备多壁碳纳米管增强铝基(MWCNTs/Al)复合材料,分析MWCNTs/Al复合材料的显微组织、硬度和磨损性能。结果表明:用RFE法可制备具有一定形状尺寸的块体MWCNTs/Al复合材料;复合材料的成形质量好,显微组织为经动态再结晶后的细小等轴晶,MWCNTs在铝合金基体中分布均匀。复合材料的硬度随着MWCNTs体积分数增加先增加后降低,当MWCNTs体积分数为4%时,硬度是经RFE加工后基材的1.2倍。MWCNTs在复合材料磨损过程中起润滑作用,有助于降低MWCNTs/Al复合材料的磨损量提高复合材料的耐磨性。随MWCNTs体积分数的增加,复合材料的磨损率降低,当MWCNTs体积分数大于3%后磨损率变化较小。这是由于MWCNTs体积分数的增加,磨损机制发生变化,即由黏着磨损和轻微磨粒磨损转变为剥层磨损和磨粒磨损。     

结合协商机制的Web服务属性访问控制模型

针对实现有效Web服务访问控制的问题,提出一种结合协商机制的Web服务属性访问控制模型。该模型基于安全断言标记语言和可扩展访问控制标识语言,利用主体属性和上下文属性的组合限制条件,提供细粒度的访问控制。通过加入协商机制,服务请求者可以与服务提供者相互沟通,在访问请求中动态地调整参数信息以获得访问授权。     

基于双边多议题的Pareto最优协商研究

研究完全信息情况下的双边多议题协商问题,提出一种双方反提议决策模型,在每一轮反提议生成过程中,提议方在满足自身效用在该轮的保留效用水平下,最大化对方的效用,从而使协商结果达到Pareto最优,同时对双方在不同让步策略下的协商结果进行算例分析,为基于双方合作的完全信息协商提供理论参考。     

基于灰色聚类的谈判对手选择模型

介绍基于多Agent的谈判对手选择方法,利用灰色理论对信息不确定情况下的谈判对手属性进行模糊区间处理,从知识库中获取灰色区间值信息,在此基础上构造关系-利益双因素模型。通过计算理想对手评估向量,设置白化权函数,对多属性的谈判对手进行综合灰色聚类分析,给出具体算例进行验证。该方法能够完善不确知信息条件下的谈判对手选择,提高谈判对环境信息的适应性。     

多Agent谈判中议题相关性及权重度量研究

已有的多议题谈判研究局限于议题相互独立、议题权重固定等前提假设。针对该问题,提出一种议题分组算法。采用移动平均法和事例推理法使用户能更灵活地设定权重,根据单个议题权重初值的确定函数以及议题组的权重求解规则,给出分组变化时的权重动态变更算法。分析结果表明,该算法能解决多议题谈判中的议题相关性问题和议题权重的动态度量问题,使多议题谈判更加科学合理。     

DFANS: A highly efficient strategy for automated trust negotiation

Automated trust negotiation (ATN) is an approach establishing mutual trust between strangers wishing to share resources or conduct business by gradually requesting and disclosing digitally signed credentials. The digital credentials themselves are usually sensitive, so they have corresponding access control policies to control their disclosure. Therefore, an ATN strategy must be adopted to determine the search for a successful negotiation based on the access control policies. Previously proposed negotiation strategies are either not complete, disclosing irrelevant credentials, or not efficient enough. In this paper, we propose a novel ATN strategy, that is, Deterministic Finite Automaton Negotiation Strategy (DFANS). DFANS is complete and ensures that no irrelevant credentials are disclosed during the negotiation. Furthermore, DFANS is highly efficient. In the worst case, its communication complexity is O(n), where n is the total number of credentials requested, and its computational complexity is O(m) when not involving the cyclic dependencies, where m is the total size of the both sides' policies looked up during the negotiation. When cyclic dependencies exist, a reasonable additional cost of running OSBE protocol that is a provably secure and quite efficient scheme will be added to the computational cost of DFANS to guarantee the negotiation success whenever possible.     

面向用户的IMS媒体层统一安全框架

针对IMS媒体层安全保护机制存在的问题,提出一个面向用户的IMS媒体层统-安全框架,在此基础上设计了具体的实现方案,该方案能为用户提供灵活的媒体层安全保护机制,实现媒体层加密算法与密钥的安全协商,保证用户之间端到端的通信安全。实验结果证明了该方案的有效性。     

通用的个性化自动谈判服务框架及其实现

针对目前缺少从用户的个性化服务需求到主体服务实现角度设计的通用框架的问题,给出一个通用的个性化自动谈判框架。提出用户个性化服务需求转换为主体服务实现的方法和主体谈判服务的实现步骤,通过一个典型案例的实现与分析结果表明,该框架具有较好的实用性。     

Quickly locating efficient, equitable deals in automated negotiations under two-sided information uncertainty

This paper develops an automated negotiation procedure inclusive of mechanism design and agent design for bilateral multi-issue negotiations under two-sided information uncertainty. The proposed negotiation mechanism comprises a protocol called MUP (Monotonic Utility-granting Protocol) and a matching strategy called WYDIWYG (What You Display Influences What You Get). The proposed preference elicitation procedure makes the agents faithful surrogates of the user they represent while the proposed Frontier Tracking Proposal Construction Algorithm (FTPCA) makes them learn the opponent's flexibility in negotiation and respond appropriately. The mechanism design and the agent design together help in locating efficient and equitable deals quickly. The efficiency, stability, simplicity, distribution symmetry and incentive compatibility of the proposed procedure are demonstrated through negotiation simulation experiments.