新型无线传感器网络启发式拓扑控制算法研究

提出了一种基于RNG图的启发式无线传感器网络拓扑控制算法HLRNG(Heuristic Local RelativeNeighbor Graph),采用RNG图和节点状态转化模型,建立从感应事件节点到sink节点间的局部多路径,以减少冗余路径并降低空闲节点的能耗。NS2仿真测试表明,HLRNG算法有效的延长了网络生命周期。     

Haar类正交变换在数字水印中的应用

论文采取变尺度、多变换的策略,将Haar类正交变换应用于载体为图像的数字水印中。即不同的图像区域,子块尺寸不完全相同,相同尺寸的子块,所采用的正交变换不完全相同。实验结果证明:这种对图像采取分而治之的对策:不仅增强了水印的不可见性和鲁棒性,也提高了水印的抗攻击性,同时达到了图像高度压缩的目的。不仅如此,文中的正交变换的计算量小,均是即位算法,特别适宜并行计算。另外,文中水印为二值图像,且是盲水印。     

A revised additivity rule for electron scattering from ethylene, propene, butene, ethane, propane and butane

Considering the difference between the bound atom in a molecule and the free atom, the original additivity rule is revised. Using the revised additivity rule, the total cross sections for electron scattering by ethylene (C₂H₄), propene (C₃H₆), butene (C₄H₈), ethane (C₂H₆), propane (C₃H₈) and butane (C₄H₁₀) are calculated over the energy range 10-1000 eV. The results of the revised additivity rule are compared with those obtained by experiments and the revised additivity rule can give better agreement with experimental values than the original additivity rule.     

西铭矿陷落柱分布规律及形成机理研究

陷落柱是地层中存在的一种特殊的地质构造,对矿井安全生产造成巨大的威胁。本文以西山煤电集团西铭矿实际条件,分析陷落柱形成的力学机理,并研究西铭矿井田范围内的陷落柱分布规律,为合理预测陷落柱位置提供一定参考价值。     

形式美法则在针织面料设计中的运用

基于形式美对比法则、均衡法则、韵律法则的内涵及其在针织面料设计中的应用规律,从深浅、虚实、肌理、曲直、高低等视角选取典型案例对针织面料进行分析,得出针织面料在形式上具有的独特意趣与艺术价值,并探讨其形式美及审美意义.通过分析针织技术与形式美法则之间的关联,探寻针织面料中形式美法则的作用及其基本规律与原理,以此指导针织面...     

Geometric acceleration of complex chemical equilibrium calculations — Performance in two- to five-component systems

Incorporating multicomponent, multiphase, complex chemical equilibrium calculations into process and multiphysics models can provide significant insights into industrial processes that current modelling or measurements cannot. Equilibrium calculations are however, in general, omitted or incorporated in a simplified manner due to their computational expense. Several methods have been developed to accelerate these calculations.A new accelerator algorithm was developed (Roos and Zietsman, 2021) based on phase diagram geometry, the Gibbs phase rule, and the lever rule to include equilibrium calculations into models more efficiently. This framework of established thermochemical theory provides a sound basis for discretisation and interpolation, and allows the accelerator algorithm to work in systems with any number of components. The work presented here aimed to test accelerator performance and demonstrate that it has the capability of achieving noteworthy levels of acceleration while maintaining acceptable accuracy.The accelerator was tested on ten 2-component systems, four 3-component systems, a simplified 4-component ilmenite smelting system, and a simplified 5-component iron- and steelmaking system. As the number of system components increased, so did the computational expense of direct equilibrium calculations. This translated to larger acceleration factors for higher-order systems — from 20 in 2-component systems to 1000 in the 5-component system. In a small number of cases it was observed that the acceleration factor was smaller than one during interpolation. This was attributed to slow searching times for suitable interpolation cells from the database.Phase composition interpolation errors are less than 1 10^-2 mol mol⁻¹. This translates to an interpolated phase composition being accurate to within 99 % of the calculated composition and results in phase fraction errors of 1 10^-2 and less. In a very small number of cases the interpolation errors made on physical and thermochemical properties are as high 10 %. This is because system properties are calculated as a phase fraction weighted sum of phase properties and errors made on system properties can therefore become large due to interpolation errors being made twice. However, the majority of errors made on physical and thermochemical properties are in the order of 1 % and less. The level of accuracy achieved by the accelerator algorithm was acceptable for the chosen discretisation tolerances.