一种抗阻断攻击的认证组密钥协商协议

一个非认证的组密钥协商协议不能对通信参与者和消息进行认证,它必须依赖认证的网络信道或其它的认证方法.分析了Burmester等人在认证广播信道下提出的著名组密钥协商协议,指出它不能抵抗内部恶意节点发起的密钥协商阻断攻击,该攻击导致组内其它诚实节点不能正确计算出一致的组密钥.提出了一种改进的认证的组密钥协商协议,在原协议中加入了消息正确性的认证方法,能够对组内恶意节点进行检测,并在随机预言模型下证明了改进的协议能够抵抗密钥协商阻断攻击.     

一种基于双线性配对的移动自组网密钥协商协议

移动自组网是一种无固定网络基础设施、能量和计算资源有限的分布式动态网络,由于其无线传输链路的开放性,使得它非常需要一种计算和通信开销较小的密钥协商方案.本文基于椭圆曲线上双线性配对的概念,提出了一种适用于移动自组网的可认证密钥协商方案,既实现了邻居节点组成员身份认证的匿名性,也实现了需建立会话的节点之间的可认证密钥协商.分析表明,我们所提出的方案计算和通信开销比较小,安全性较好,非常适合于资源有限的移动自组网.     

Ad Hoc网络中一种基于环状分层结构的组密钥协商协议

移动ad hoc网络是一种新型的移动多跳无线网络.其自身的特征,如网络规模庞大、动态的拓扑结构、有限的计算、通信和存储能力等,使得传统的密钥分配和管理机制无法直接应用于该网络.提出了一种新的适用于移动 ad hoc网络的组密钥协商协议.该协议在环状分层结构上基于多线性映射进行组密钥的协商和分配,使得节点在密钥协商过程中具有低计算开销与低通信开销的优势,较好地解决了在移动ad hoc网络中进行组密钥协商时所遇到的节点能量受限问题,适用于移动ad hoc网络.     

一种实用的Ad hoc网络鉴别路由协议AARP

针对Ad hoc网络的鉴别路由协议ARAN存在路由查找过程复杂、计算复杂度高、缺乏会话密钥协商等缺点,本文提出了一种简单实用的鉴别路由协议AARP.该协议避免采用公钥加密算法,简化了路由查找过程,降低了计算复杂度,利用节点对路由消息的签名,有效抵制了各种恶意攻击,同时利用DH交换,完成会话密钥协商.本文还通过CK模型分析了AARP协议的安全性,结果表明:若DDH假设成立、数字签名算法可抵抗选择消息攻击,则AARP协议在UM下是SK-secure的,且具有完善的前向保密性PFS、已知密钥安全KKS等属性.相比ARAN协议,AARP对于通常节点资源受限的Ad hoe网络而言,更为实用.     

一种基于逻辑程序的重复协商框架

本文从基于信念修改的角度提出了两个AGENT之间的一个重复协商框架.在这个框架中,一个逻辑程序被当作一个协商的AGENT,每一个AGENT(逻辑程序)选择自己的一个回答作为自己最初的协商需求.两个AGENT之间的协商过程就是两个逻辑程序之间相互更新的过程,这个过程是通过协商的每一方接受对方的部分(或,全部)需求和放弃自己部分协商需求来实现的.本文设计了协商双方必须遵守的一些协商规则,根据这些规则对这个协商框架进行了形式化描述,并给出了协商的终止条件.     

E-mail安全协议PGP

本文从单钥密码IDEA算法、双钥密码RsA算法、单向杂凑算法MD5算法等分析了安全电子邮件协议PGP的实现原理和实现流程;描述了PGP所提供的安全业务;并从RSA、IDEA、MD5、随机数等安全性方面分别研究了PGP的安全性能.     

一起主动脉瘤伴急性阑尾炎猝死协商解决的思考

临床上由于猝死引起的医疗纠纷较为常见,本文剖析了一起胸主动脉夹层动脉瘤伴急性阑尾炎术后第3天破裂性出血心包填塞猝死引起的医疗纠纷,医患双方从不同的角度围绕医方是否存在漏诊、误诊、有无医疗过失及患者疾病的特殊性、不可预见性等开展讨论,最终在上级卫生行政部门的参与下,探讨协商解决的办法,由医院和患者家属共同鉴定协议,公证处公证后生效,对医疗纠纷的协商解决有一定的借鉴作用。     

基于交互历史的多Agent自动协商研究

在多Agent协商过程中,初始信念起到了至关重要的作用.而初始信念的形成是由设计者给予的部分专家知识和策略集,成功的交互历史是Agent在复杂环境中最后达成一致的提议集.通过学习机制从交互历史中获得知识,形成协商的初始信念,将更加有效地预测对方的策略,缩短协商过程的时间,再通过在线学习来协调己方Agent的行为.在此基础上优化协商模型,提高协商的效率和成功率.     

基于SOA的多边多议题协商模型的研究

提出了一种新的协商模型--基于面向服务架构(SOA)的多边多议题协商模型.利用面向服务架构(SOA)技术来构建松散耦合的协商模型,并在协商模型中应用本体的基本理论和相关技术来定义提议、议题等本体模型,以实现协商议题的多样性和可变性,最后在SOA的框架下以Web服务方式使用经SOAP封装的通信原语实现多边多议题协商模型.     

协商解决医疗纠纷的技巧

医疗纠纷是近年来社会热点问题之一,成因繁杂.协商解决医疗纠纷是<医疗事故处理条例>处理医疗纠纷、医疗争议的三种解决方式之一,协商解决具有低成本、高效率,缓和医患矛盾等优点[1].医患双方协商解决作为解决医疗纠纷的首选途径,是一门艺术,院方应掌握其技巧,以维护双方合法权益.     

Protocols forstability testing

Protocol planning for stability testing is influenced by several factors such as physicochemical properties of the drug, type of product, regulatory requirements of the intended market and the proposed uses of the data obtained. In addition to specific job requirements, the priority allocation and the availability of resources also affect the protocol design. This review describes the objects and design of protocols for stability evaluation with particular emphasis on relatively unstable compounds. The relevance of stability testing to various stages of product development is examined. Problems of shelf-life assignment, preparation of samples for inspection, use of controls and extrapolation of results are also discussed.     

Assessing Individual Agreement

Evaluating agreement between measurement methods or between observers is important in method comparison studies and in reliability studies. Often we are interested in whether a new method can replace an existing invasive or expensive method, or whether multiple methods or multiple observers can be used interchangeably. Ideally, interchangeability is established only if individual measurements from different methods are similar to replicated measurements from the same method. This is the concept of individual equivalence. Interchangeability between methods is similar to bioequivalence between drugs in bioequivalence studies. Following the FDA guidelines on individual bioequivalence, we propose to assess individual agreement among multiple methods via individual equivalence using the moment criteria. In the case where there is a reference method, we extend the individual bioequivalence criteria to individual equivalence criteria and propose to use individual equivalence coefficient (IEC) to compare multiple methods to one or multiple references. In the case where there is no reference method available, we propose a new IEC to assess individual agreement between multiple methods. Furthermore, we propose a coefficient of individual agreement (CIA) that links the IEC with two recent agreement indices. A method of moments is used for estimation, where one can utilize output from ANOVA models. The nonparametric and bootstrap approaches are used for inference. Five examples are used for illustration.     

医疗器械国家重点实验室申报工作实践与思考

目的:回顾与总结2018年食品药品监管领域医疗器械国家重点实验室的申报及评定工作,为其他实验室申报国家重点实验室提供借鉴。方法:着力阐述申报资料的准备过程,对评定机构的组成及评定方式进行详细的介绍,深入分析评定指标,并针对重点实验室的建设提出建议。结果与结论:国家重点实验室的申报工作使得实验室自身的软、硬件实力得以全面展示。由于思想上重视,准备工作做得充分、细致,推动了医疗器械重点实验室在运行管理上与时俱进、不断创新,加强了医疗器械重点实验室的全面建设与管理。经过评定工作的历练,医疗器械重点实验室更加充满活力。     

Comparison of Concordance Correlation Coefficient and Coefficient of Individual Agreement in Assessing Agreement

Phase II clinical trials are conducted to test whether a drug has a minimum desired effect and to assess whether further development of the drug is warranted. They are often designed as one-arm trials with response rate as the primary endpoint, and a two-stage design is often used to ensure early termination of the trial for futility. To control the type I error rate and guarantee the specified power of the study, planned sample sizes for both stages must be rigidly followed, but a literature review suggests that actual sample size often differs from that planned. We propose to extend simple two-stage designs to allow more flexible sampling plans in both stages. Our designs are preferable to similar extensions proposed to control type I and II error probabilities. Additionally, our assumptions regarding distribution of the actual sample size at the end of stage 1 are more lenient. A list of optimal designs for typical error rates and the selected null and alternative response rates is presented.