Deep holes are very important in the decoding of generalized RS codes, and deep holes of RS codes have been widely studied, but there are few works on constructing general linear codes based on deep holes. Therefore, ...Deep holes are very important in the decoding of generalized RS codes, and deep holes of RS codes have been widely studied, but there are few works on constructing general linear codes based on deep holes. Therefore, we consider constructing binary linear codes by combining deep holes with binary BCH codes. In this article, we consider the 2-error-correcting binary primitive BCH codes and the extended codes to construct new binary linear codes by combining them with deep holes, respectively. Furthermore, three classes of binary linear codes are constructed, and then we determine the parameters and the weight distributions of these new binary linear codes.展开更多
The design of a bolted flat cover is extremely important for the structural integrity of pressure vessels.The present design codes provide the thickness calculation equations for a bolted flat cover with single metal ...The design of a bolted flat cover is extremely important for the structural integrity of pressure vessels.The present design codes provide the thickness calculation equations for a bolted flat cover with single metal gasket.However,the rules for a bolted flat cover with double metal sealing rings are not developed to date.In the study,a new thickness calculation equation for the bolted flat cover with double metal sealing rings is proposed.First,the theoretical stress solution for bolted flat cover with the double metal sealing rings is obtained,based on the theory of simply supported circular plate and then verified using the results from finite element analyses.The results indicate that the influence of double metal sealing ring on the stress of the flat cover is more serious compared to single metal gasket.Second,a more accurate and reasonable equation is proposed to calculate the thickness of bolted flat cover with double metal sealing rings based on the derived theoretical equations of maximum stress.Finally,the influence of linear load and the spacing between rings on the thickness are discussed.Subsequently,a few suggestions are provided to design low-pressure or atmosphere pressure vessels.The study provides a theoretical foundation to develop design codes of pressure vessels in nuclear reactors.展开更多
带噪声奇偶学习问题(learning parity with noise,LPN)是密码学中的一类重要困难问题,它可以视作随机线性码译码问题的一般形式,是抗量子假设中的有力候选.在求解LPN问题前,通常需要执行约简操作,将待求实例转化为秘密长度更短的实例....带噪声奇偶学习问题(learning parity with noise,LPN)是密码学中的一类重要困难问题,它可以视作随机线性码译码问题的一般形式,是抗量子假设中的有力候选.在求解LPN问题前,通常需要执行约简操作,将待求实例转化为秘密长度更短的实例.本文提出了一种新的混合约简算法Hybrid,它将经典的丢弃约简算法和覆盖码约简算法相结合,在约简过程中丢弃与码字距离超过给定界限的LPN样本,而非将所有样本直接近似到码字.这种新的约简方法可以到达权衡样本复杂度和时间复杂度的目的.从算法层面讲,丢弃约简与覆盖码约简可以视作混合约简的特例.最后,使用池化高斯算法求解经过混合约简后的LPN样本,给出了其完整的理论复杂度.数值估计的结果表明混合约简可以进一步缩减良好池化高斯算法(Well-Pooled Gauss)的样本复杂度,但需要以时间开销上升为代价.展开更多
二进制翻译技术能够有效解决二进制兼容问题,促进新型体系结构的发展,也是虚拟机技术的重要组成部分,具有重要的研究和应用价值,但是其效率仍然有待提升,特别是目标代码生成的效率。设计了一种高效的目标代码生成算法——代码生成的子...二进制翻译技术能够有效解决二进制兼容问题,促进新型体系结构的发展,也是虚拟机技术的重要组成部分,具有重要的研究和应用价值,但是其效率仍然有待提升,特别是目标代码生成的效率。设计了一种高效的目标代码生成算法——代码生成的子图覆盖算法(subgraph covering for code generation,SCCG),能够以尽可能少的代价生成精简的目标代码。该算法应用数据流图对二进制代码中的基本块进行建模,获取指令间的数据相关,并采用基于子图覆盖的贪心算法得到目标代码。在TransARM原型系统中进行了实现和测试,结果表明该算法获得了更优质的目标代码,并且成本得到了有效控制。展开更多
文摘Deep holes are very important in the decoding of generalized RS codes, and deep holes of RS codes have been widely studied, but there are few works on constructing general linear codes based on deep holes. Therefore, we consider constructing binary linear codes by combining deep holes with binary BCH codes. In this article, we consider the 2-error-correcting binary primitive BCH codes and the extended codes to construct new binary linear codes by combining them with deep holes, respectively. Furthermore, three classes of binary linear codes are constructed, and then we determine the parameters and the weight distributions of these new binary linear codes.
基金supported by the‘‘Strategic Priority Research Program’’of the Chinese Academy of Sciences(No.XDA02010000)
文摘The design of a bolted flat cover is extremely important for the structural integrity of pressure vessels.The present design codes provide the thickness calculation equations for a bolted flat cover with single metal gasket.However,the rules for a bolted flat cover with double metal sealing rings are not developed to date.In the study,a new thickness calculation equation for the bolted flat cover with double metal sealing rings is proposed.First,the theoretical stress solution for bolted flat cover with the double metal sealing rings is obtained,based on the theory of simply supported circular plate and then verified using the results from finite element analyses.The results indicate that the influence of double metal sealing ring on the stress of the flat cover is more serious compared to single metal gasket.Second,a more accurate and reasonable equation is proposed to calculate the thickness of bolted flat cover with double metal sealing rings based on the derived theoretical equations of maximum stress.Finally,the influence of linear load and the spacing between rings on the thickness are discussed.Subsequently,a few suggestions are provided to design low-pressure or atmosphere pressure vessels.The study provides a theoretical foundation to develop design codes of pressure vessels in nuclear reactors.
文摘带噪声奇偶学习问题(learning parity with noise,LPN)是密码学中的一类重要困难问题,它可以视作随机线性码译码问题的一般形式,是抗量子假设中的有力候选.在求解LPN问题前,通常需要执行约简操作,将待求实例转化为秘密长度更短的实例.本文提出了一种新的混合约简算法Hybrid,它将经典的丢弃约简算法和覆盖码约简算法相结合,在约简过程中丢弃与码字距离超过给定界限的LPN样本,而非将所有样本直接近似到码字.这种新的约简方法可以到达权衡样本复杂度和时间复杂度的目的.从算法层面讲,丢弃约简与覆盖码约简可以视作混合约简的特例.最后,使用池化高斯算法求解经过混合约简后的LPN样本,给出了其完整的理论复杂度.数值估计的结果表明混合约简可以进一步缩减良好池化高斯算法(Well-Pooled Gauss)的样本复杂度,但需要以时间开销上升为代价.
文摘二进制翻译技术能够有效解决二进制兼容问题,促进新型体系结构的发展,也是虚拟机技术的重要组成部分,具有重要的研究和应用价值,但是其效率仍然有待提升,特别是目标代码生成的效率。设计了一种高效的目标代码生成算法——代码生成的子图覆盖算法(subgraph covering for code generation,SCCG),能够以尽可能少的代价生成精简的目标代码。该算法应用数据流图对二进制代码中的基本块进行建模,获取指令间的数据相关,并采用基于子图覆盖的贪心算法得到目标代码。在TransARM原型系统中进行了实现和测试,结果表明该算法获得了更优质的目标代码,并且成本得到了有效控制。
