It is important to achieve continuous, stable and efficient pumping well operation in actual oilfield operation. Down-hole pumping well working conditions can be monitored in real-time and a reasonable production sche...It is important to achieve continuous, stable and efficient pumping well operation in actual oilfield operation. Down-hole pumping well working conditions can be monitored in real-time and a reasonable production scheme can be designed when computer diagnosis is used. However, it is difficult to make a comprehensive analysis to supply efficient technical guidance for operation of the pumping well with multiple faults of down-hole conditions, which cannot be effectively dealt with by the common methods. To solve this problem, a method based on designated component analysis (DCA) is used in this paper. Freeman chain code is used to represent the down-hole dynamometer card whose important characteristics are extracted to construct a designated mode set. A control chart is used as a basis for fault detection. The upper and lower control lines on the control chart are determined from standard samples in normal working conditions. In an incompletely orthogonal mode, the designated mode set could be divided into some subsets in which the modes are completely orthogonal. The observed data is projected into each designated mode to realize fault detection according to the upper and lower control lines. The examples show that the proposed method can effectively diagnose multiple faults of down-hole conditions.展开更多
A new method for solving the tiling problem of surface reconstruction is proposed. The proposed method uses a snake algorithm to segment the original images, the contours are then transformed into strings by Freeman'...A new method for solving the tiling problem of surface reconstruction is proposed. The proposed method uses a snake algorithm to segment the original images, the contours are then transformed into strings by Freeman' s code. Symbolic string matching technique is applied to establish a correspondence between the two consecutive contours. The surface is composed of the pieces reconstructed from the correspondence points. Experimental results show that the proposed method exhibits a good behavior for the quality of surface reconstruction and its time complexity is proportional to mn where m and n are the numbers of vertices of the two consecutive slices, respectively.展开更多
Permutation codes over finite chain rings are introduced; by using the character of the finite chain rings and the knowledge of representation of group, some conditions for existence or non-existence of self-dual perm...Permutation codes over finite chain rings are introduced; by using the character of the finite chain rings and the knowledge of representation of group, some conditions for existence or non-existence of self-dual permutation codes over finite chain rings are obtained. Specially, when the group is a direct product of a 2-group and a T-group, and the group action is transitive, the sufficient and necessary condition of the existence of permutation codes is given.展开更多
For at least the past five decades,structural synthesis has been used as a main means of finding better mechanisms with some predefined function.In structural synthesis,isomorphism identification is still a problem un...For at least the past five decades,structural synthesis has been used as a main means of finding better mechanisms with some predefined function.In structural synthesis,isomorphism identification is still a problem unsolved well,and to solve this problem is very significant to the design of new mechanisms.According to the given degree of freedom(DOF) and link connection property of planar closed chain mechanisms,vertex assortment is obtained.For solving the isomorphism problem,a method of the adding sub-chains is proposed with the detailed steps and algorithms in the synthesizing process.Employing this method,the identification code and formation code of every topological structure are achieved,therefore many isomorphic structures could be eliminated in time during structural synthesis by comparing those codes among different topological graphs,resulting in the improvement of synthesizing efficiency and accuracy,and the approach for eliminating rigid sub-chains in and after the synthesizing process is also presented.Some examples are given,including how to add sub-chains,how to detect simple rigid sub-chains and how to obtain identification codes and formulation codes et al.Using the adding sub-chain method,the relative information of some common topological graphs is given in the form of table.The comparison result is coincident with many literatures,so the correctness of the adding sub-chain method is convinced.This method will greatly improve the synthesizing efficiency and accuracy,and has a good potential for application.展开更多
In this article, cyclic codes and negacyclic codes over formal power series rings are studied. The structure of cyclic codes over this class of rings is given, and the relationship between these codes and cyclic codes...In this article, cyclic codes and negacyclic codes over formal power series rings are studied. The structure of cyclic codes over this class of rings is given, and the relationship between these codes and cyclic codes over finite chain rings is obtained. Using an isomorphism between cyclic and negacyclic codes over formal power series rings, the structure of negacyclic codes over the formal power series rings is obtained.展开更多
In this article, we focus on cyclic and negacyclic codes of length 2p^s over the ring R = Fp^m + uFp^m, where p is an odd prime. On the basis of the works of Dinh (in J.Algebra 324,940-950,2010), we use the Chinese...In this article, we focus on cyclic and negacyclic codes of length 2p^s over the ring R = Fp^m + uFp^m, where p is an odd prime. On the basis of the works of Dinh (in J.Algebra 324,940-950,2010), we use the Chinese Remainder Theorem to establish the algebraic structure of cyclic and negacyclic codes of length 2p^s over the ring Fp^m + uFp^m in terms of polynomial generators. Furthermore, we obtain the number of codewords in each of those cyclic and negacyclic codes.展开更多
随着大语言模型(large language model,LLM)在代码生成领域的快速发展,其生成的代码在智能化基础软件供应链中的应用日益广泛.基础软件供应链中集成了大量基于LLM生成代码开发的第三方模块与组件.然而,由于LLM主要基于开源代码进行训练...随着大语言模型(large language model,LLM)在代码生成领域的快速发展,其生成的代码在智能化基础软件供应链中的应用日益广泛.基础软件供应链中集成了大量基于LLM生成代码开发的第三方模块与组件.然而,由于LLM主要基于开源代码进行训练,训练代码中的缺陷与安全漏洞可能会导致生成代码存在潜在错误与供应链安全问题.为此,学术界有针对性地提出了EvalPlus等测试技术,但这些技术主要依赖基于概率的测试用例生成机制,难以实现对供应链关键路径的全面覆盖,导致深层次逻辑性缺陷难以被有效发现.为了解决上述问题,提出一种融合符号执行的供应链LLM生成代码的缺陷检测方法.该方法通过符号执行挂载机制自动识别LLM生成代码的输入参数并进行适配和符号挂载,制导符号执行引擎对程序的关键路径进行精确的约束分析,生成高效的边界测试用例,从而发现现有方法难以检测到的深层逻辑性程序缺陷.在现有主流基准数据集上,对LMSYS Chatbot Arena中排名前11的主流LLM进行了实验评估.实验结果表明,该方法能够更有效地检测出LLM生成代码中的逻辑性缺陷,使代码的平均测试通过率降低了3.99%–18.98%,平均测试覆盖率提高了3.31%–8.19%,有效提升了LLM生成代码的正确性和智能化基础软件供应链的安全性.展开更多
数字化浪潮下,软件供应链安全成为支撑数字经济安全稳定发展的必要环节.系统综述软件供应链安全检测评估技术体系,从软件成分分析(software component analysis,SCA)、软件物料清单(software bill of material,SBOM)、依赖关系追溯等核...数字化浪潮下,软件供应链安全成为支撑数字经济安全稳定发展的必要环节.系统综述软件供应链安全检测评估技术体系,从软件成分分析(software component analysis,SCA)、软件物料清单(software bill of material,SBOM)、依赖关系追溯等核心技术出发,针对软件检测和评价中关键的技术——组件分析、漏洞扫描、代码审查等,分析当前面临的问题与解决思路,再通过国内外最新的研究成果和应用案例进行对比论述,结合兴业证券SCA治理平台、中国电信SBOM管理平台等典型实践,并就SLSA框架、GitHub依赖图谱等新兴前沿技术发展状况进行分析.在此基础上针对该领域的技术发展现状及产业需要展望技术融合与协同、智能化与自动化、全生命周期覆盖等未来10年发展10大趋势.展开更多
基金supported by the Key Program of National Natural Science Foundation of China (61034005)Postgraduate Scientific Research and Innovation Projects of Basic Scientific Research Operating Expensesof Ministry of Education (N100604001)Excellent Doctoral Dissertations Cultivation Project of Northeastern University
摘要It is important to achieve continuous, stable and efficient pumping well operation in actual oilfield operation. Down-hole pumping well working conditions can be monitored in real-time and a reasonable production scheme can be designed when computer diagnosis is used. However, it is difficult to make a comprehensive analysis to supply efficient technical guidance for operation of the pumping well with multiple faults of down-hole conditions, which cannot be effectively dealt with by the common methods. To solve this problem, a method based on designated component analysis (DCA) is used in this paper. Freeman chain code is used to represent the down-hole dynamometer card whose important characteristics are extracted to construct a designated mode set. A control chart is used as a basis for fault detection. The upper and lower control lines on the control chart are determined from standard samples in normal working conditions. In an incompletely orthogonal mode, the designated mode set could be divided into some subsets in which the modes are completely orthogonal. The observed data is projected into each designated mode to realize fault detection according to the upper and lower control lines. The examples show that the proposed method can effectively diagnose multiple faults of down-hole conditions.
摘要A new method for solving the tiling problem of surface reconstruction is proposed. The proposed method uses a snake algorithm to segment the original images, the contours are then transformed into strings by Freeman' s code. Symbolic string matching technique is applied to establish a correspondence between the two consecutive contours. The surface is composed of the pieces reconstructed from the correspondence points. Experimental results show that the proposed method exhibits a good behavior for the quality of surface reconstruction and its time complexity is proportional to mn where m and n are the numbers of vertices of the two consecutive slices, respectively.
基金Supported by the National Natural Science Foundation of China (60373087, 60473023, 90104005, 60673071)
摘要Permutation codes over finite chain rings are introduced; by using the character of the finite chain rings and the knowledge of representation of group, some conditions for existence or non-existence of self-dual permutation codes over finite chain rings are obtained. Specially, when the group is a direct product of a 2-group and a T-group, and the group action is transitive, the sufficient and necessary condition of the existence of permutation codes is given.
基金supported by National Natural Science Foundation of China (Grant No. 51075079)National Hi-tech Research and Development Program of China(863 Program,Grant No. 2008AA04Z202)
摘要For at least the past five decades,structural synthesis has been used as a main means of finding better mechanisms with some predefined function.In structural synthesis,isomorphism identification is still a problem unsolved well,and to solve this problem is very significant to the design of new mechanisms.According to the given degree of freedom(DOF) and link connection property of planar closed chain mechanisms,vertex assortment is obtained.For solving the isomorphism problem,a method of the adding sub-chains is proposed with the detailed steps and algorithms in the synthesizing process.Employing this method,the identification code and formation code of every topological structure are achieved,therefore many isomorphic structures could be eliminated in time during structural synthesis by comparing those codes among different topological graphs,resulting in the improvement of synthesizing efficiency and accuracy,and the approach for eliminating rigid sub-chains in and after the synthesizing process is also presented.Some examples are given,including how to add sub-chains,how to detect simple rigid sub-chains and how to obtain identification codes and formulation codes et al.Using the adding sub-chain method,the relative information of some common topological graphs is given in the form of table.The comparison result is coincident with many literatures,so the correctness of the adding sub-chain method is convinced.This method will greatly improve the synthesizing efficiency and accuracy,and has a good potential for application.
基金supported by SRF for ROCS,SEM,the Key Project of Chinese Ministry of Education (108099)CCNU Project (CCNU09Y01003)
摘要In this article, cyclic codes and negacyclic codes over formal power series rings are studied. The structure of cyclic codes over this class of rings is given, and the relationship between these codes and cyclic codes over finite chain rings is obtained. Using an isomorphism between cyclic and negacyclic codes over formal power series rings, the structure of negacyclic codes over the formal power series rings is obtained.
基金supported by the Natural ScienceFoundation of Hubei Province(D2014401)the Natural Science Foundation of Hubei Polytechnic University(12xjz14A)
摘要In this article, we focus on cyclic and negacyclic codes of length 2p^s over the ring R = Fp^m + uFp^m, where p is an odd prime. On the basis of the works of Dinh (in J.Algebra 324,940-950,2010), we use the Chinese Remainder Theorem to establish the algebraic structure of cyclic and negacyclic codes of length 2p^s over the ring Fp^m + uFp^m in terms of polynomial generators. Furthermore, we obtain the number of codewords in each of those cyclic and negacyclic codes.
摘要随着大语言模型(large language model,LLM)在代码生成领域的快速发展,其生成的代码在智能化基础软件供应链中的应用日益广泛.基础软件供应链中集成了大量基于LLM生成代码开发的第三方模块与组件.然而,由于LLM主要基于开源代码进行训练,训练代码中的缺陷与安全漏洞可能会导致生成代码存在潜在错误与供应链安全问题.为此,学术界有针对性地提出了EvalPlus等测试技术,但这些技术主要依赖基于概率的测试用例生成机制,难以实现对供应链关键路径的全面覆盖,导致深层次逻辑性缺陷难以被有效发现.为了解决上述问题,提出一种融合符号执行的供应链LLM生成代码的缺陷检测方法.该方法通过符号执行挂载机制自动识别LLM生成代码的输入参数并进行适配和符号挂载,制导符号执行引擎对程序的关键路径进行精确的约束分析,生成高效的边界测试用例,从而发现现有方法难以检测到的深层逻辑性程序缺陷.在现有主流基准数据集上,对LMSYS Chatbot Arena中排名前11的主流LLM进行了实验评估.实验结果表明,该方法能够更有效地检测出LLM生成代码中的逻辑性缺陷,使代码的平均测试通过率降低了3.99%–18.98%,平均测试覆盖率提高了3.31%–8.19%,有效提升了LLM生成代码的正确性和智能化基础软件供应链的安全性.
摘要数字化浪潮下,软件供应链安全成为支撑数字经济安全稳定发展的必要环节.系统综述软件供应链安全检测评估技术体系,从软件成分分析(software component analysis,SCA)、软件物料清单(software bill of material,SBOM)、依赖关系追溯等核心技术出发,针对软件检测和评价中关键的技术——组件分析、漏洞扫描、代码审查等,分析当前面临的问题与解决思路,再通过国内外最新的研究成果和应用案例进行对比论述,结合兴业证券SCA治理平台、中国电信SBOM管理平台等典型实践,并就SLSA框架、GitHub依赖图谱等新兴前沿技术发展状况进行分析.在此基础上针对该领域的技术发展现状及产业需要展望技术融合与协同、智能化与自动化、全生命周期覆盖等未来10年发展10大趋势.