热带粗轧机组立轧稳定轧制变形规律的实验研究和有限元分析

本文采用铅作为模拟材料，对热带粗轧机组平辊立轧变形规律进行了实验研究，得到了表征立轧稳定轧制阶段时轧件断面特征的四个参量与侧压量、立辊直径、板坯来料厚度及宽度之间的关系。并首次提出用超薄单元近似处理奇异点的新方法，采用全三维刚塑性可压缩有限元法对立轧稳态过程进行了理论解析，所得结果和实验结果符合较好。     

热带粗轧机组立轧变形规律研究

以铅为模拟材料，对热带粗轧机组平辊立轧变形规律进行了实验研究，分析了稳定轧制阶段表征立轧时轧件断面特征的４个参量，及非稳定轧制阶段头、尾部最大狗骨高度非稳定行为，失宽行为，鱼尾长度与立辊直径、侧压量、板坯来料厚度及宽度之间的关系，并建立了新的数学模型．     

稀土纳米磁致冷复合材料

采用急冷快淬，高能球磨及粉末包套包覆轧制方法制备出Ｇｄ－Ｙ，Ｇｄ－Ｚｎ和Ｇｄ－Ｔｈ的纳米固体复合磁致冷材料。实验测试结果表明：与大块状材料相比，纳米固体的居里温度明显降低，比热显著增加：Ｇｄ－Ｔｈ和Ｇｄ－Ｚｎ合金的磁热熵效应有所降低，但Ｇｄ－Ｙ系的磁热熵效应则显著增加。对制备工艺条件及若干影响磁质变熵效应的因素进行了较详细的分析。     

RGB-D Hand-Held Ob ject Recognition Based on Heterogeneous Feature Fusion

Ob ject recognition has many applications in human-machine interaction and multimedia retrieval. However, due to large intra-class variability and inter-class similarity, accurate recognition relying o...     

KICA模式匹配的动态过程监控与故障诊断方法

针对复杂化工过程具有的非线性、非高斯性和动态特征,提出了基于核独立成分分析(KICA)的模式匹配方法,用于动态过程监控和诊断。首先,利用滑动窗建立基准集与测试集的KICA模型,提取各自的核独立元:其次,融合余弦函数绝对值度量和距离度量,提出新的不相似度监控指标,识别训练与测试操作期间的相似模式,进行故障检测:最后,基于两类数据的核子空间之间的差异子空间,获得每个过程变量方向与该差异子空间之间的互信息,并定义新的非线性非高斯贡献度指标,进行故障诊断。基于污水处理过程的仿真结果表明,与主成分分析不相似度因子的方法、标准的独立成分分析(ICA)统计指标方法及标准的ICA T~2/SPE指标融合的贡献度方法相比,本文提出的方法具有更好的检测能力与故障诊断效果。     

A noise immunity controlled quantum teleportation protocol

Quantum Information Processing - With the advent of the Internet and information and communication technology, quantum teleportation has become an important field in information security and its...     

A secure and high-performance multi-controller architecture for software-defined networking

Controllers play a critical role in software-defined networking (SDN). However, existing single-controller SDN architectures are vulnerable to single-point failures, where a controller’s capacity can be saturated by flooded flow requests. In addition, due to the complicated interactions between applications and controllers, the flow setup latency is relatively large. To address the above security and performance issues of current SDN controllers, we propose distributed rule store (DRS), a new multi-controller architecture for SDNs. In DRS, the controller caches the flow rules calculated by applications, and distributes these rules to multiple controller instances. Each controller instance holds only a subset of all rules, and periodically checks the consistency of flow rules with each other. Requests from switches are distributed among multiple controllers, in order to mitigate controller capacity saturation attack. At the same time, when rules at one controller are maliciously modified, they can be detected and recovered in time. We implement DRS based on Floodlight and evaluate it with extensive emulation. The results show that DRS can effectively maintain a consistently distributed rule store, and at the same time can achieve a shorter flow setup time and a higher processing throughput, compared with ONOS and Floodlight.     

A virtual service placement approach based on improved quantum genetic algorithm

Despite the critical role that middleboxes play in introducing new network functionality, management and innovation of them are still severe challenges for network operators, since traditional middleboxes based on hardware lack service flexibility and scalability. Recently, though new networking technologies, such as network function virtualization (NFV) and software-defined networking (SDN), are considered as very promising drivers to design cost-efficient middlebox service architectures, how to guarantee transmission efficiency has drawn little attention under the condition of adding virtual service process for traffic. Therefore, we focus on the service deployment problem to reduce the transport delay in the network with a combination of NFV and SDN. First, a framework is designed for service placement decision, and an integer linear programming model is proposed to resolve the service placement and minimize the network transport delay. Then a heuristic solution is designed based on the improved quantum genetic algorithm. Experimental results show that our proposed method can calculate automatically the optimal placement schemes. Our scheme can achieve lower overall transport delay for a network compared with other schemes and reduce 30% of the average traffic transport delay compared with the random placement scheme.