关于单形外接球半径与内切球半径的两个不等式

建立了ｎ维欧氏空间Ｅｎ中ｎ维单形的外接球半径与内切球半径的两个不等式,改进了ｎ维Ｅｕｌｅｒ不等式和已有文献的结果．     

关于单形体积与棱长的两个几何不等式

获得了涉及ｎ维单形的体积与棱长的两个几何不等式，推广了已有文献的有关结果．     

D-optimal design for a quadratic log contrast model for experiments with mixtures

A practical method is suggested for solving complicated D-optimal design problems analytically. Using this method the author has solved the problem for a quadratic log contrast model for experiments with mixtures introduced by J. Aitchison and J. Bacon-Shone. It is found that for a symmetric subspace of the finite dimensional simplex, the vertices and the centroid of this subspace are the only possible support points for a D-optimal design. The weights that must be assigned to these support points contain irrational numbers and are constrained by a system of three simultaneous linear equations, except for the special cases of 1- and 2-dimensional simplexes where the situation is much simpler. Numerical values for the solution are given up to the 19-dimensional simplex     

关于n维单形宽度的一个结果

证明了关于ｎ维单形宽度的一个不等式，结果是Ｗ≤（ｓｉｎθ）１／２αｎ１ｎ＋１ｎ＋１ｉ＝１Ｒ２ｉ１／２．这一结果蕴含并推广了Ｓａｌｅｅ－Ａｌｅｘａｎｄｅｒ定理     

关于E~n中n维单形的两个恒等式及其应用

获得了Ｅｎ中ｎ维单形的两个恒等式，利用它们得到了著名的ｎ维Ｅｕｌｅｒ不等式及其推广、Ｇｅｒｂｅｒ不等式的推广以及垂足单形不等式．     

浅议钢琴教学中踏板的运用

在钢琴演奏中 ,“踏板是钢琴的灵魂”。正确地运用踏板 ,能使音乐更加具有艺术表现力。本文针对踏板的种类和特点 ,对踏板的作用及运用进行了简要的论述 ,对提高学琴者的艺术表现力有一定的借鉴     

Optimal designs for experiments with mixtures: a survey

This is a survey article on known results about analytic solutions and numerical solutions of optimal designs for various regression models for experiments with mixtures. The regression models include polynomial models, models containing homogeneous functions, models containing inverse terms and ratios, log contrast models, models with quantitative variables, and mod els containing the amount of mixture, Optimality criteria considered include D-, A-, E-,φ_p- and I_λ-Optimalities. Uniform design and uniform optimal design for mixture components, and efficiencies of the {q,2} simplex-controid design are briefly discussed.     

Logratio approach to statistical analysis of 2×2 compositional tables

Compositional tables represent a continuous counterpart to well-known contingency tables. Their cells contain quantitatively expressed relative contributions of a whole, carrying exclusively relative information and are popularly represented in proportions or percentages. The resulting factors, corresponding to rows and columns of the table, can be inspected similarly as with contingency tables, e.g. for their mutual independent behaviour. The nature of compositional tables requires a specific geometrical treatment, represented by the Aitchison geometry on the simplex. The properties of the Aitchison geometry allow a decomposition of the original table into its independent and interactive parts. Moreover, the specific case of 2×2 compositional tables allows the construction of easily interpretable orthonormal coordinates (resulting from the isometric logratio transformation) for the original table and its decompositions. Consequently, for a sample of compositional tables both explorative statistical analysis like graphical inspection of the independent and interactive parts or any statistical inference (odds-ratio-like testing of independence) can be performed. Theoretical advancements of the presented approach are demonstrated using two economic applications.