City metro tunnels are usually constructed as twin-parallel tunnels and their adjacent construction may lead to surface deformation,affecting the surface environment and the safety of the tunnels.Due to its strong dis...City metro tunnels are usually constructed as twin-parallel tunnels and their adjacent construction may lead to surface deformation,affecting the surface environment and the safety of the tunnels.Due to its strong dispersion,sandy cobble strata can be easily disturbed by shield tunneling.Based on the project of the Chengdu Metro Line 1,field and model tests were carried out to study the surface settlement caused by shield tunneling in sandy cobble strata by measuring surface settlement curves,ground loss ratios and construction influence zones.The discrete element method(DEM) was used to study the factors affecting the formation of ground arches in sandy cobble strata at the microscopic level.Results show that the shape of the surface settlement curve in sandy cobble strata is different from that in soft soil.The buried depth and clear spacing of the two tunnels had a significant impact on the formation of ground arches.展开更多
三维片上网络(3D No C)中IP核的测试问题日趋突出,测试规划是提高测试效率的有效方法。基于重用No C作为测试存取机制的并行测试方法,针对IP核测试数据传输带宽与TAM带宽不匹配的问题,提出带分复用方法,对有限带宽的TAM进行动态细分,将...三维片上网络(3D No C)中IP核的测试问题日趋突出,测试规划是提高测试效率的有效方法。基于重用No C作为测试存取机制的并行测试方法,针对IP核测试数据传输带宽与TAM带宽不匹配的问题,提出带分复用方法,对有限带宽的TAM进行动态细分,将多核的测试数据共享同一物理TAM实施并行传输,并结合3D No C结构设计二维编码,建立带宽分配和测试顺序模型,采用多种群遗传模拟退火算法,在总功耗、层功耗双重约束下对IP核的带宽分配和测试顺序进行双重优化,提高并行测试效率以获得最短测试时间。算法中针对测试顺序优化设计移位互换杂交策略,并运用精英配对方法加快种群寻优速度,设计求精操作进一步优化测试时间,通过比较、淘汰、替换机制加强种群间交流,增加种群多样性,避免算法陷入局部最优。以ITC'02标准电路作为测试对象,实验结果表明,该方法通过提高带宽利用率,提升了并行测试效率,降低了资源占用,有效地缩短了测试时间。展开更多
基金Project supported by the National Basic Research (973) Program of China (No. 2010CB732105)the National Natural Science Foundation of China (Nos. 50908193,50925830,and 51208432)
文摘City metro tunnels are usually constructed as twin-parallel tunnels and their adjacent construction may lead to surface deformation,affecting the surface environment and the safety of the tunnels.Due to its strong dispersion,sandy cobble strata can be easily disturbed by shield tunneling.Based on the project of the Chengdu Metro Line 1,field and model tests were carried out to study the surface settlement caused by shield tunneling in sandy cobble strata by measuring surface settlement curves,ground loss ratios and construction influence zones.The discrete element method(DEM) was used to study the factors affecting the formation of ground arches in sandy cobble strata at the microscopic level.Results show that the shape of the surface settlement curve in sandy cobble strata is different from that in soft soil.The buried depth and clear spacing of the two tunnels had a significant impact on the formation of ground arches.
文摘三维片上网络(3D No C)中IP核的测试问题日趋突出,测试规划是提高测试效率的有效方法。基于重用No C作为测试存取机制的并行测试方法,针对IP核测试数据传输带宽与TAM带宽不匹配的问题,提出带分复用方法,对有限带宽的TAM进行动态细分,将多核的测试数据共享同一物理TAM实施并行传输,并结合3D No C结构设计二维编码,建立带宽分配和测试顺序模型,采用多种群遗传模拟退火算法,在总功耗、层功耗双重约束下对IP核的带宽分配和测试顺序进行双重优化,提高并行测试效率以获得最短测试时间。算法中针对测试顺序优化设计移位互换杂交策略,并运用精英配对方法加快种群寻优速度,设计求精操作进一步优化测试时间,通过比较、淘汰、替换机制加强种群间交流,增加种群多样性,避免算法陷入局部最优。以ITC'02标准电路作为测试对象,实验结果表明,该方法通过提高带宽利用率,提升了并行测试效率,降低了资源占用,有效地缩短了测试时间。
