关于广义Ramanujan-Nagell方程x2-D=2n

借助于丢番图逼近中Beukers的一些深刻结果，讨论了广义Ramanujan—Nage11方程x^2-D=2^n。在D＝2^n十l时的一个非例外情况，求出了此时该方程的全部非负整数解。     

DIDSS环境下信息agent系统任务规范的分解

提出一个基于GDF(扩展决策函数)的多agent任务规范分解判据，提出多agent的任务规范分解性质；将多agent任务规范分解问题等价为建立一个与信息agent任务规范属性相关的MSBN(多模块贝叶斯网)问题，并证明了MSBN的d-cutset(d-割集)和分解判据之间的关系，提出了与多agent任务规范对应的MSBN的分解方法．最后通过示例验证了所提出的方法的可行性。     

对Tanh函数法的推广及其在非线性方程中的应用

为了得到非线性偏微方程的行波解,提出了一种推广的tanh函数法.这种方法的主要思想是充分利用涉及两个参变量的广义Riccati方程,用它的解去代替tanh函数解,并且能从参数的符号准确地判断出行波解的类型和个数.     

Elastic Wave Propagation Simulation in Heterogeneous Anisotropic Media on Non-uniform Grids

A finite-difference method with spatially non-uniform grids was developed to simulate elastic wave propagation in heterogeneous anisotropic media. The method is very simple and requires less compution time. Complicated geometric structures, such as low-velocity layers, cased boreholes and nonplanar interfaces, are treated with fine non-uniform grids. Unlike the multi-grid scheme, this method does not require interpolation between the fine and coarse grids and all grids are Computed in the same spatial iteration. Planar or nonplanar surfaces including underground lens and cased boreholes are easily treated in a way similar to regular grid points. The Higdon‘s absorbing boundary condition was used to eliminate boundary reflections. Numerical simulations show that the method has satisfactory stability and accuracy. The proposed scheme more efficiently simulates wave propagation in heterogeneous anisotropic media than conventional methods using regular rectangular grids of equal accuracy.     

An improvement of Papadakis'' theorem

There exist many orthonormal wavelets which cannot be derived by multiresolution analysis (MRA) with a single scaling function.In 2000,Papadakis announced that any orthonormal wavelet is derived by a generalized MRA with countable scaling functions at most.We improve Papadakis' theorem and find that for any othonormal wavelet,the least number of the corresponding scaling functions is just the essential supremum of the dimension function of the orthonormal wavelet.Moreover,we construct directly the fewest scaling functions     

观念与语言理解

观念是一种社会心理,一种意识形态,在语言表达上的体现。语言理解不仅仅是对语言、词汇、语法的识别,更重要的是对观念的理解。观念差异是造成语言理解难的一大障碍,在学习语言时,应着重注意对观念的把握与理解。     

村语与黎语词汇差异成因初探

村语和黎语虽同属一个语支,但词汇差异却高达50%以上,其直接原因主要有:底层语词和特有词的大量使用;借词取代固有词以及借词语源的不同或者借入的途径不同;借词和新造词的共存并用,新造词的语素或造词方法的不同。     

马一浮与熊十力的六艺论之异同

马一浮和熊十力都是在20世纪初中国社会全面反传统的历史背景中,挺身而出,坚决捍卫儒学价值的著名人物.二人虽相知甚深,却又和而不同.二人都以六经为依归,都以阐发六经大义为本分,但他们的六艺论,既有大纲大要上之异同,又有许多具体观点之分歧.     

浅论C/S和B/S软件系统体系结构的差异

建立一个计算机管理系统的第一步是制定一个合理的设计方案,其中最根本的就是选定最佳的系统结构模式,即系统的选型工作。本文通过探讨C/S和B/S两种结构的差异来阐述如何选定最佳的系统结构模型。     

Blind source separation of ship-radiated noise based on generalized Gaussian model

1 .INTRODUCTIONBlind source separation (BSS) in signal processinghas received considerable attention from many re-searchers .It is a fundamental problem in signalprocessing with a large number of extremely di-verse applications such as multi-user communica-tions ,speech signal processing, array processingand medical signal processing including ECG,MEGand EEG. The general goal of blind sourceseparation (BSS) is to separate the statistically in-dependent , unknown source signals from t…