投标者为风险规避型引入佣金的分析(一)

在投标者为风险规避型的情况下,考虑引入佣金对拍卖结果的影响,发现在对称独立私有价值模型中,对于密封一价拍卖和密封二价拍卖,佣金比例k越大,则投标者的报价越低,卖方的期望收益越少,拍卖行的期望收益越大,但投标者的期望效用与k无关。     

论公众参与视角下的公共政策绩效评估

政府管理与公共政策密不可分,对公共政策绩效进行评估,理应成为政府绩效评估的重要组成部分。社会公众作为受政策影响的最重要主体,应在政策绩效评估中扮演重要角色。由于公共政策本身的复杂性,公众参与公共政策绩效评估必须遵循渐进、科学、多元评估的原则,并在相关机制的支持下进行,才能促使有关方面在公共政策的制定、执行过程中关注各相关方的利益均衡,注重政策的公平性和回应性,提高公共政策的质量。     

一种基于身份私钥的秘密共享方案

基于双线性对的门限密码体制过度依赖双线性对结构,而双线性对计算复杂度较高,严重影响秘密共享方案的效率。为此,提出利用Shamir门限共享方案实现双线性对群元素门限分享的新方案,借助整数秘密共享方案间接地实现基于身份私钥的分配。分析结果表明,该方案仅需2次双线性对计算,为设计高效的基于身份的门限密码体制奠定了基础。     

公钥不可替换无证书签名方案

基于Al-Riyami框架的无证书签名(CLS)的安全性以密钥分发中心(KGC)不能实施公钥替换攻击为前提,存在能被KGC实施公钥替换攻击这一缺陷。给出公钥不可替换攻击无证书签名体制的定义,提出通过对用户的公钥签名来抵抗任何敌手(包括KGC)实施的公钥替换攻击,以将无证书签名的安全性提升到一个新的级别。基于Al-Riyami的方案给出了新方案的构造实例,基于随机预言机模型证明了公钥签名算法的安全性。该方案构造的对公钥的签名方法适用于所有基于Al-Riyami框架的双线性对无证书签名方案。     

古建筑礼屏公祠的建筑风格与特点

文章对东莞市的清代古建筑礼屏公祠进行了深入细致的调查研究，对建筑的年代、格局、形制、细节、特点与设计手法等方面进行了剖析，对相关的历史人物，近代省港知名的传奇富翁——卢赓扬做了介绍，并对该祠的历史价值做出了客观的评价。     

黄遵宪和湖南保卫局

黄遵宪是我国杰出的思想家、外交活动家,也是一个杰出的政治家,在湖南维新运动期间他主持了多项新政,其中最重要的是湖南保卫局的创办,湖南保卫局被视为中国最早的警察机构,具有深远的影响.     

基于Agent的证书路径构建方法

提出了一种采用Agent辅助PKI用户获得证书路径的方法，设计了基于Agent的PKI信任模型及Agent内部结构，并提出了Agent的证书路径更新算法。理论分析表明，在5个节点的混合信任模型及通信网络中各节点只存在一跳的情况下，该方法能提高效率约2.6倍。     

城市公交线网优化方法的应用研究

城市公交网络服务水平评价与优化是一项与城市公共交通系统规划与管理密切相关的基础技术，它是公交综合评价与优化技术的重要内容。本文采用OD分布与聚类分析相结合的方式。通过定量研究对丹东市现状公交网络进行分析评价，并提出优化方案设计建议，为城市公交线路的规划设计提供简便易行的方法。     

E-Society Portal: Integrating Urban Highway Construction Projects into the Knowledge City

Community involvement is an important factor for sustainable highway construction. Information and communication technologies provide a new and more effective approach to facilitate community involvement. However, there are too many parameters with conflicting and subjective definitions related to sustainability and too many stakeholders with varying degrees of interest and sophistication. There is a need for an effective tool to communicate project impacts on sustainability to local communities. This paper presents an ontology for stakeholder management and sustainability in highway construction. An ontology is a conceptual semantic model that attempts to capture human knowledge (both explicit and tacit) in a consistent manner. Ontologies include three main elements: a taxonomy (common vocabulary presented in concept trees), set of relationships (linking concepts across trees), and axioms (limitation/constraints on the behavior of concepts). The ontology was used to develop a portal for broadcasting highway design features to local communities. By browsing through the portal, a user can learn about project elements, the impacts of each element on sustainability issues, who is sponsoring such element, and what efforts have been made to reduce any impacts of such elements on local communities.     

Solving large multiple-depot multiple-vehicle-type bus scheduling problems in practice

We consider the multiple-depot multiple-vehicle-type scheduling problem (MDVSP) which arises in public transport bus companies and aims to assign buses to cover a given set of timetabled trips with consideration of practical requirements, such as multiple depots and vehicle types as well as depot capacities. An optimal schedule is characterized by minimal fleet size and minimal operational costs including costs for empty movements and waiting time. It is well-known that the MDVSP is NP-hard.Although progress has recently been made in solving large practical MDVSP to optimality with time-space network models, current optimization technology sets limits to the model size that can be solved. In order to approach very large practical instances we propose a two-phase method which produces close to optimal solutions. This modeling approach enables us to solve real-world problem instances with thousands of scheduled trips by direct application of standard optimization software. Furthermore, we introduce the concept of depot groups for the case that a bus may return in the evening into another depot than where it started in the morning.