二重积分优化Simpson与二次式算法

本文给出区域D=(a≤x≤b,φ(x)≤y≤_ψ(x))上二重积分的优化Simpson算法和∫_a~∞∫_b~∞f(x,y)dxdy的优化二次式算法,它们在迭代计算时避免了函数值的重复计算,减少迭代次数。     

Hilbert投影距离在非线性算子方程求解和固有元问题中的应用

Hilbert投影距离被引入之后,许多作者对它和它的应用进行了研究,但往往要求算子具有较好的性质。本文试图减弱对算子的要求从而使Hilbert投影距离得到更广泛的应用。 设E是实Banach空间,P?E是正规锥,由[3]中定理1.5知道存在E上等价范数使此范数关于锥P单调,即任给x、y∈P,x≤y(这表示y-x∈P)都有‖x‖≤‖y‖,因此不妨设E的原     

关于算子方程Tx=y扰动分析的一些结果

在Banach空间中给出了一种相容算子方程解的误差估计,推广了矩阵扰动分析中的相应结果,此外,利用Hilbert空间中算子M－P广义逆与算子的约化极小模之间的关系,给出了一些估计式,这些估计式对于分析不相容算子方程Tx=y的极小范数最小二乘解的扰动误差是有用的。     

关于一类插值多项式的最高收敛阶

以第一类Tchebyshev多项式的零点作为插值节点，推广了伯恩斯坦提出的一个问题，构造了插值多项式算子Gn,b(f;x)，它不仅对f(x)∈C^a[-1,1](p≤a≤b-1，其中b为自然数）一致收敛，而且收剑阶达到了最佳。对算子Gn,b(f;x)，最高收敛阶不会超过1/n^6，这是对伯恩斯坦所提出问题的一个圆满的回答。     

一种基于单调多边形的三角剖分算法

提出了一种基于单调多边形三角化算法,被三角化的多边形可以含有任意个内孔。先根据边界y（x）方向的局部极值顶点作水平（垂直）分割线,将多边形划分成单连通y（x）单调多边形,然后再将各单调多边形三角化。算法考虑了各种几何奇异情况,因此比较稳定。     

大型旋转机械故障诊断专家系统ETHYLENE的理论研究

本文在模糊产生式规则的基础上引入了加权模糊连接算子的概念,并研究了征兆的类型。在此基础上,为旋转机械模糊诊断知识提出了一个灵活的知识表达方法——广义模糊产生式规则。在征兆类型的基础上引入了征兆认可因子的概念.利用这一概念来描述模糊蕴涵关系的语义,基于征兆认可因子提出了一个模糊推理算法。文中还给出了由基于这一广义模糊产生式规则和模糊推理算法建立的透平压缩机组故障诊断专家系统ETHYLENE得到的两个诊断结果。     

关于Gruenwald型多项式算子的线性组合

研究了Gruenwald型多项式算子Hn(f;x,r)对f(x)∈C^j[-1,1],1≤j≤r的逼近阶，在连续状态下给出了点态的逼近阶。     

关于Grünwald型多项式算子的线性组合

研究了Grünwald型多项式算子Hn(f;x,r)对f(x)∈Cj[-1,1],1≤j≤r的逼近阶,在连续状态下给出了点态的逼近阶.     

Banach格上的b-AM-紧算子(英文)

本文对Banach格上的b-AM-紧算子进行了描述,得到了如下三个结论:1)如果Banach格F是无限维的,则E是KB-空间当且仅当每个从E到F的AM-紧算子是b-AM-紧算子。2)Banach格E是离散的KB-空间当且仅当每个从E到F的连续算子是b-AM-紧算子。3)如果E是离散的,则每个从E到F的b-弱紧算子是b-AM-紧算子。其次给出了b-AM-紧算子的控制性质,得到如下两个结论:1)如果E和F是两个Banach格,算子S,T:E→F满足0≤S≤T且T是b-AM-紧算子,则算子S是b-AM-紧算子当且仅当F具有序连续范数或者E是离散空间。2)如果S,T是从E到F的算子满足0≤S≤T,如果T是b-AM-紧算子,则S2也是b-AM-紧算子。     

一类 (E_2 )的三次曲线分界线环(英文)

得到了一类平面二次系统存在三次曲线分界线环的充分必要条件。这种类型的分界线环的方程为y2 (x +a) +x2 (x - b) =0　 (a >0 ,b >0 )。     

由规则并算子构造的泛模糊逼近器的充要条件

通过引进规则并算子的概念,本文给出31个规则并算子;证明了三角模是规则并算子;给出由规则并算子构造的控制器是泛模糊逼近器的充要条件。     

Nonstoichiometry and superconductivity in LaxMo6Sy

Lanthanum Chevrel type compounds, La_xMo₆S_y (0.9 ≤ x ≤ 1.1, and 7.0 ≤ y ≤ 8.0 in nominal content), are prepared by sintering at 1623 and 1773 K in a vacuum sealed Mo container. All of the samples heated at 1623 K accompany with impurity phases. The hexagonal c/a ratio varies from 1.2488 to 1.2620, and the superconducting critical temperature T_c is a monotonic function of c/a. On the other hand, the samples heated at 1773 K have a single phase in the region of 1.0 ≤ x ≤ 1.1, and 7.4 ≤ y ≤ 8.0. They show the c/a ratios from 1.220 to 1.254, but T_c is almost constant and independent of c/a. These relations between T_c and c/a are explained by the dependence of the Fermi level on the c/a ratio.     

特征展开三I Fuzzy推理模型及其在专家系统中的应用

推导出了专家系统中基于三Ⅰ机制的特征展开Fuzzy推理模型。以作物病虫害的诊断与防治专家系统为实例，在雄风4.1专家系统开发平台中，巧妙运用规则对象块的“规则架 规则体“的规则组织知识表示方法，实现了该平台上的特征展开三ⅠFuzzy推理。给出了其Fuzzy EBNF语法定义，讨论了采用知识表示策略实现Fuzzy推理的灵活优越性。该模型在雄风系列专家系统开发平台中尚属首次使用，并且具有广泛的适用性。     

La_(1-x)Sr_xCoO_3体系的绝缘体-金属相变

通过粉末X射线衍射分析确定了钙钛矿氧化物La1-xSrxCoO3(0.1≤x≤0.5)体系的结构,由Ri-etveld方法拟合得到晶格参数随Sr掺杂量的变化.在80~300 K温度范围的直流电阻率测量表明,材料的电性质在x=0.2和x=0.3之间展示了从半导体到金属的相变.x=0.2样品已接近绝缘体-金属(I—M)相变的边缘.研究结果表明,La1-xSrxCoO3(0.1≤x≤0.5)体系的I-M相变不仅依赖于Sr浓度x,也依赖于样品的制备技术.     

基于直觉模糊张量的决策方法及其应用

对具有高维数据特征的直觉模糊决策问题进行了研究,定义了直觉模糊张量的一般形式和运算法则;建立了基于直觉模糊张量的广义直觉模糊加权平均算子,探索了广义直觉模糊加权平均算子的基本性质;证明了广义直觉模糊加权平均算子是直觉模糊加权平均算子的一般形式。提出了基于广义直觉模糊加权平均算子的决策方法,通过算例验证了该方法能够有效解决具有高维数据特征的直觉模糊决策问题。     

Fermatean Hesitant Fuzzy Prioritized Heronian Mean Operator and Its Application in Multi-Attribute Decision Making

In real life, incomplete information, inaccurate data, and the preferences of decision-makers during qualitative judgment would impact the process of decision-making. As a technical instrument that can successfully handle uncertain information, Fermatean fuzzy sets have recently been used to solve the multi-attribute decision-making (MADM) problems. This paper proposes a Fermatean hesitant fuzzy information aggregation method to address the problem of fusion where the membership, non-membership, and priority are considered simultaneously. Combining the Fermatean hesitant fuzzy sets with Heronian Mean operators, this paper proposes the Fermatean hesitant fuzzy Heronian mean (FHFHM) operator and the Fermatean hesitant fuzzy weighted Heronian mean (FHFWHM) operator. Then, considering the priority relationship between attributes is often easier to obtain than the weight of attributes, this paper defines a new Fermatean hesitant fuzzy prioritized Heronian mean operator (FHFPHM), and discusses its elegant properties such as idempotency, boundedness and monotonicity in detail. Later, for problems with unknown weights and the Fermatean hesitant fuzzy information, a MADM approach based on prioritized attributes is proposed, which can effectively depict the correlation between attributes and avoid the influence of subjective factors on the results. Finally, a numerical example of multi-sensor electronic surveillance is applied to verify the feasibility and validity of the method proposed in this paper.     

Fringe-density estimation by continuous wavelet transform

For many phase extraction algorithms, a priori knowledge of a fringe-pattern density distribution is beneficial for later processing. A fringe-density estimation method based on a continuous wavelet transform (CWT) is proposed. For a one-dimensional signal the instantaneous frequency detected at the CWT ridge is directly adopted as a measure of the local fringe density. For a two-dimensional signal the instantaneous frequency components in both the x and the y directions are detected. Their reliability is evaluated by the CWT coefficient magnitude, based on which an approximate density value is given. The capability for noise reduction and the accuracy of the method are discussed.     

Numerically robust minimal‐scan reconstruction algorithms for diffraction tomography via radon transform inversion

It is widely believed that measurements from a full angular range of 2π are generally required to exactly reconstruct a complex‐valued refractive index distribution in diffraction tomography (DT). In this work, we developed a new class of minimal‐scan reconstruction algorithms for DT that utilizes measurements only over the angular range 0 ≤ ? ≤ 3π/2 to perform an exact reconstruction. These algorithms, referred to as minimal‐scan estimate‐combination (MS‐E‐C) reconstruction algorithms, effectively operate by transforming the DT reconstruction problem into a conventional x‐ray CT reconstruction problem that requires inversion of the Radon transform. We performed computer simulations to compare the noise and numerical properties of the MS‐E‐C algorithms against existing filtered backpropagation‐based algorithms. © 2002 Wiley Periodicals, Inc. Int J Imaging Syst Technol 12, 84–91, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ima.10014