一种基于数据的一致性进行知识简约方法

文章从基于条件属性等价划分与研究论域对象的覆盖率入手,提出了一种新的数据一致性概念,基于数据的一致性概念进行知识简化,比粗集理论中利用知识的依赖性研究知识简化概念更清楚,方法更简便。结合实例分析、处理大型的知识表达系统,研究经典CTR汽车数据库的知识简化,实验结果证明了本文方法的可行性和有效性。     

非线性分数阶微分方程的Radau IIA方法

基于Riemann-Liouville分数阶导数的RadauIIA方法高阶逼近格式,枸造了求解非线性分数阶微分方程的Radau IIA方法,给出了方法的相容性、收敛性和稳定性分析。数值试验表明所构造的方法是有效的。     

分布式存储环境下工作流相关数据的一致性更新

为了解决分布存储机制带来的工作流相关数据的一致性问题,提出了一种动态TTL自适应策略.在该策略中,主本数据节点计算主本TTL,副本数据节点在更新数据时可获得这个主本TTL;计算副本TTL时,从主本TTL中除去副本更新与主本最后提交的时间间隔,使副本失效时间与主本的下次提交时间基本同步,从而提高了副本的新鲜率,而副本的更新率并未显著增加.与现有的弱一致性更新策略相比,提出的策略具有一定优势.从理论上分析了该策略的性能,模拟实验的结果也验证了这一结论.     

一类位置不变的Hill型估计量的渐近性质

作者在正规变换条件下证明了一类位置不变的Hill型估计量强收敛速度和强相合性.     

基于本体的汽轮发电机组故障诊断知识建模

针对目前汽轮发电机组故障诊断领域知识术语复杂、系统异构、知识表示不完备以及共享和重复使用困难等问题,依据故障诊断需求,采用基于本体的知识表示方法,提出了一种适用于汽轮发电机组故障诊断领域的本体构建方法和知识表示模型.在解析了汽轮发电机组故障知识特性的前提下,定义了其本体概念、属性、关系、实例和公理,为知识表示提供了明确的形式化规格说明,并借助Protégé_4.3构建了包含汽轮发电机组的故障类型、故障特征、故障原因和维修策略等故障诊断领域本体,设计了一致性检验的算法.在此基础上,在SQI机械故障综合模拟实验台上模拟汽轮发电机组故障,通过FaCT++推理机实现本体知识推理测试.结果表明基于本体的汽轮发电机组故障诊断知识模型是可行的.     

牛顿方法的用导一致性

导数及其使用是一种重要的数学工具与方法,在数值方法研究中起着十分重要的作用,很多经典数值计算方法理论中都涉及了对导数的运用.作为常用的数值方法,牛顿方法大量利用了求导的思想.通过归纳牛顿迭代法的显性用导特性和牛顿插值多项式的隐性用导特性,得到牛顿方法的用导一致性.     

Efficient multiuser detector based on box-constrained deregularization and its FPGA design

Multiuser detection can be described as a quadratic optimization problem with binary constraint.Many techniques are available to find approximate solution to this problem.These techniques can be characterized in terms of complexity and detection performance.The "efficient frontier" of known techniques include the decision-feedback,branch-and-bound and probabilistic data association detectors.The presented iterative multiuser detection technique is based on joint deregularized and box-constrained solution to quadratic optimization with iterations similar to that used in the nonstationary Tikhonov iterated algorithm.The deregularization maximizes the energy of the solution,this is opposite to the Tikhonov regularization where the energy is minimized.However,combined with box-constraints,the deregularization forces the solution to be close to the binary set.We further exploit the boxconstrained dichotomous coordinate descent (DCD) algorithm and adapt it to the nonstationary iterative Tikhonov regularization to present an efficient detector.As a result,the worst-case and average complexity are reduced down to 2.8 and 2.5 floating point operation per second,respectively.The development improves the "efficient frontier" in multiuser detection,which is illustrated by simulation results.Finally,a field programmable gate array (FPGA) design of the detector is presented.The detection performance obtained from the fixed-point FPGA implementation shows a good match to the floating-point implementation.     

一种基于区间语言判断矩阵的群决策模型

研究了偏好信息为区间语言判断矩阵的群决策问题．创建一个转换公式,将专家个体区间语言判断矩阵转化为区间数互补判断矩阵,并对判断矩阵转换的一致性进行了系统地研究;通过将区间数互补判断矩阵进行加权算术平均集结为专家群组区间数互补判断矩阵,进而利用区间数互补判断矩阵的排序向量方法求出专家群组排序向量,从而实现备选方案的排序和择优．最后通过算例说明了方法的可行性与有效性．     

Building Hot Snapshot Copy Based on Windows File System

This paper describes a method for building hot snapshot copy based on windows-file system （HSCF）. The architecture and running mechanism of HSCF are discussed after giving a comparison with other on-line backup tecbnology. HSCF, based on a file system filter driver, protects computer data and ensures their integrity and consistency with following three steps： access to open files, synchronization and copy on-write. Its strategies for improving system performance are analyzed including priority setting, incremental snapshot and load balance. HSCF is a new kind of snapshot technology to solve the data integrity and consistency problem in online backup, which is different from other storage-level snapshot and Open File Solution.