基于EXTEND的排队规则仿真研究

排队系统是一种典型的离散事件动态系统,在不同的排队规则下会有不同的系统特性。通过仿真软件EXTEND对不同排队规则下的排队系统进行了建模及仿真。在分析仿真结果的基础上,探讨了不同排队规则下排队系统的内在规律。     

套管防磨保护措施

在深井,特别在高温高压深探井中,套管的磨损是一个比较突出的问题,且保护套管和保护钻杆往往是矛盾的。崖城4井采取控制平台漂移、钻直表层井段、采用合适的钻具来控制井斜和减小井斜变化率、选用合适的钻杆等作业保护措施非常成功地达到了既保护了套管,钻杆也没有出现过度磨损的目的。介绍了该井凭借有关资料制定的相应保护措施,通过与其他井的情况对比,分析总结了该井成功经验,可为以后钻探同类型的井提供一些启示。     

现浇混凝土构件与砌体接触面收缩和温度应力裂纹的探讨

分析讨论了建筑物由于收缩及温度应力而引起的过纹，提出了在设计施工中应考虑的问题和采取的防止措施。     

Comparison of interfaces in Ti composites reinforced with uncoated and TiB2/C-coated SiC fibres

Interfaces play an important role in determining the mechanical properties of composite materials. The interfaces established between a titanium-alloy matrix (Ti-6Al-4V) and uncoated and TiB₂/C-coated SiC fibres are analysed by scanning electron microscopy, transmission electron microscopy and X-ray techniques. Emphasis is placed upon the interfacial morphology and microstructure, identification of reaction products, and the stability of the coating layer. Complex multi-reaction layers are observed frequently in the interfacial zones. Previous, often contradictory, reports about the interlayers are reviewed. Experimental observation demonstrates that the type and distribution of interlayers vary in a given system, due to prolonged treatment of the samples at temperature. The formation and distribution of the interlayers are discussed further, with respect to these and previous findings. Methods of reducing interfacial reactivity are discussed.     

用熔融还原的方法从浸钒渣中提镓——碳饱和情况下的熔融还原过程

用通用旋转组合设计的方法得到了浸钒渣在饱和碳的熔融还原过程中镓的还原提取率与温度,时间及CaO的加入量关系的非线性数学模型。用非线性优化的方法并综合考虑Fe,Mn的回收,得到了最优的工艺条件及结果;用Langmuir—Knudsen方程推算了镓在铁液中的理论挥发量与时间的关系,与由本模型得到的关系式是一致的。     

一种保护标价的多属性反向拍卖模型

多属性反向拍卖作为一种电子采购方式已被广泛应用于电子商务中.在大多数拍卖模型中,投标者的标价信息对于拍卖者来说完全公开,在拍卖者和个别投标者共谋情况下,会造成投标者之间的地位不平等,给其他投标者造成经济损失.文中在逼近理想解评标方法和安全多方计算基础上,提出一种保护标价的多属性反向拍卖模型,该模型采用了安全逼近理想解协议,实现标价保密和投标者地位公平,抵御拍卖者与个别投标者的共谋.     

基于共同好友数的在线社会网络社区发现算法

为了快速准确地找到在线社会网络的社区结构,提出了一种基于共同好友数和节点邻居信息的社区结构发现算法。该算法以共同好友数最多的两个节点为初始社区,不断寻找与社区连接性最强的节点,并以节点Q值为衡量标准,判断是否将该节点加入到初始社区中,最后根据节点邻居所在初始社区信息确定最终的社区划分。针对两个经典社会网络和人工生成网络数据的实验划分结果表明,该算法是可行和有效的。     

CS3000顺控表的组态和应用

介绍CS3000系统顺控表的结构、参数定义和功能块组态,以聚丙烯加氢控制为例,描述顺控表的组态方法、顺控动作和操作步骤等。     

Achieving fair service with a hybrid scheduling scheme for CICQ switches

Providing performance guarantees for arriving traffic flows has become an important measure for today’s routing and switching systems. However, none of current scheduling algorithms built on CICQ (combined input and cross-point buffered) switches can provide flow level performance guarantees. Aiming at meeting this requirement, the feasibility of implementing flow level scheduling is discussed thoroughly. Then, based on the discussion, it comes up with a hybrid and stratified fair scheduling (HSFS) scheme, which is hierarchical and hybrid, for CICQ switches. With HSFS, each input port and output port can schedule variable length packets independently with a complexity of O(1). Theoretical analysis show that HSFS can provide delay bound, service rate and fair performance guarantees without speedup. Finally, we implement HSFS in SPES (switch performance evaluation system) to verify the analytical results.