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
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
为实现高分辨率遥感影像低层特征的有效组织与优化,提高特征的可判别性,重点研究了基于稀疏编码的中层特征学习、基于支持向量机(Support Vector Machine,SVM)的分类技术,提出了基于软概率级联中层特征学习模型实现土地利用/土地覆盖(La...为实现高分辨率遥感影像低层特征的有效组织与优化,提高特征的可判别性,重点研究了基于稀疏编码的中层特征学习、基于支持向量机(Support Vector Machine,SVM)的分类技术,提出了基于软概率级联中层特征学习模型实现土地利用/土地覆盖(Land Use and Land Cover,LULC)分类。首先,提取影像的灰度共生矩阵(Graylevel Co-occurrence Matrix,GLCM)、光谱特征、密集尺度不变特征转换(Dense Scale Invariant Feature Transform,DSIFT)作为低层特征;然后由稀疏编码分别对GLCM、DSIFT和光谱特征进行稀疏编码,并结合最大平滑方法对稀疏系数进行优化,获得影像的中层特征,并通过SVM分类器分别计算LULC类别软概率,对其级联获得影像的特征表达;最后,利用SVM分类器再次分类获得LULC分类结果。选用武汉市远城区农村居民点作为实验样区,对该方法进行了验证,实验结果表明,该方法总体精度达到88%左右;相较于提取单一低层特征的分类方法,本文算法可有效提高LULC分类精度。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。
文摘为实现高分辨率遥感影像低层特征的有效组织与优化,提高特征的可判别性,重点研究了基于稀疏编码的中层特征学习、基于支持向量机(Support Vector Machine,SVM)的分类技术,提出了基于软概率级联中层特征学习模型实现土地利用/土地覆盖(Land Use and Land Cover,LULC)分类。首先,提取影像的灰度共生矩阵(Graylevel Co-occurrence Matrix,GLCM)、光谱特征、密集尺度不变特征转换(Dense Scale Invariant Feature Transform,DSIFT)作为低层特征;然后由稀疏编码分别对GLCM、DSIFT和光谱特征进行稀疏编码,并结合最大平滑方法对稀疏系数进行优化,获得影像的中层特征,并通过SVM分类器分别计算LULC类别软概率,对其级联获得影像的特征表达;最后,利用SVM分类器再次分类获得LULC分类结果。选用武汉市远城区农村居民点作为实验样区,对该方法进行了验证,实验结果表明,该方法总体精度达到88%左右;相较于提取单一低层特征的分类方法,本文算法可有效提高LULC分类精度。
