蛋白质序列的一类新的二维图形表示及其应用

基于20种氨基酸的一种5-字母模型,提出了蛋白质序列的一类CGR图形表示,并在此基础上给出蛋白质序列的一种36维向量表示.对11个物种的β球蛋白序列的相似性分析证实了我们的方法的有用性.     

蛋白质序列的一种新的二维图形表示

基于氨基酸的五字母模型,提出蛋白质序列的一种二维图形表示方法,然后证明这种图是非退化的.最后用该方法给出了8个物种的β球蛋白序列的图形表示.     

用基于模糊聚类的Kruskal算法构建进化树

对线粒体DNA序列可通过图形表示及计算曲线的散度均值来构造模糊论中的相似矩阵，基于这些，提出一种新的方法：用模糊聚类图论法中的Kruskal算法来进行系统进化树的重构，并选取了8个物种的线粒体DNA序列来说明此方法．     

代数问题的几何解法

解析几何是用代数方法研究几何问题的一门学科,具体的说,就是借助于坐标系,用坐标表示点,用曲线上点的坐标所满足的方程表示曲线,通过研究方程的性质间接的研究曲线的性质,从而把几何上的许多图形、概念给出了其代数表示.     

基于曲线曲面图形神经网络学习方法的研究

提出一种基于曲线曲面图形神经网络学习方法，即由点集构成的曲线曲面图形作为神经网络的学习样本，利用人工神经网络直接对曲线、曲面进行学习和训练，并以曲线、曲面图形的直观显示来表示网络的训练效果。同时还提出了基于曲线曲面图形神经网络结构的构建方法和训练过程的改进方案。实验结果表明，该构建方法和改进方案在提高训练精度、加快收敛速度方面收到了较好的效果。     

空间解析几何柱面的3D动画表现

空间解析几何与3D动画是两个完全不同的学科,对空间解析几何图形在3D动画中表现的研究,是一个新的尝试.柱面母线移动应用3D动画常规技术不能以动态化视觉图形表现出来;3D动画没有曲线方程,不能精确绘制双曲线等准曲线,进而使这种柱面难以表现.通过对两个学科的比较分析,深度挖掘3D动画技术,采取3D动画模型库中的模型直接创建柱面、手工绘制准曲线、表达式表示准曲线的柱面表现这三种方法,将柱面在3D动画中表现出来,使得空间解析几何中的图形变得真实、艺术和富有生命.     

计算机图形学中曲线的数学表示

在计算机图形学软件及算法的研究里面,要用到大量的数学基础知识。从图形对象的表示到对图形的处理,包括变换、裁剪、消隐等,分别涉及数学的参数方程、微积分、离散数学、平面及空间解析几何等各个分支。建立合适的数学模型,寻找适当的处理方式,对计算机图形学中问题的解决无疑会有很大的帮助。本文列出计算机图形学中几种曲线的数学表示方法,供使用时参考。曲线有参数表示和非参数表示之分,在非参数表示中又分为显式和隐式表示。从计算机图形学和计算几何的角度看,一般使用参数方程表示较好。1.显式表示对于一条平面曲线,显式的非参数方程…     

定积分中极坐标方程表示图形的困惑

用极坐标系描述的曲线方程称作极坐标方程,通常表示r为θ的函数,这不同于直角坐标系下的方程.由于同学们对极坐标不熟悉,造成对于一些极坐标方程表示的图形很迷惑.这里由一个极易引起疏忽的例子来说明作出极坐标方程的图形时需要注意的几个方面.     

解读高考试题中的一类新图形——双纵坐标图

自从2008年江苏高考中首次出现了双纵坐标图之后,在近几年高考中也出现了双纵坐标图形.这类图形由于图中至少有三个坐标,即一个横坐标,两个纵坐标,图形中一般往往有三条以上的曲线,信息量明显加大,图形之间的联系较复杂,对审题读图能力提出了更高的要求,对学生思维品质考查的更加全面.综合分析各类考试中出现的双纵坐标图,供大家参考.一、双纵坐标表示相同物理量此类图形两个纵坐标表示相同的物理量,在数据分析时只要比较图形在纵坐标数量上的差异.结合数据大小比较,可以采用相关措施,达到实验目的.     

基于序列、结构和芯片数据的聚类算法

运用图论中的一系列思想对生物序列、蛋白质结构和基因芯片数据进行综合分析,将多物种的序列进行聚类,为生物基因的功能研究提供了新的思路.其算法首先根据生物序列的相似度、蛋白质结构的相似度和基因芯片数据的相似度建立一级图,然后根据一级图建立二级图,进而通过二级图的分析来挖掘基因的聚类关系.算法聚类的结果可以对各种基因的功能进行预测,可广泛应用于后基因组计划的基因和蛋白质研究.     

DNA的二维图表示

给出了新的DNA二维图表示,证明了该表示是非退化的,并提出了一种新的DNA相似度计算方法.     

Exploring the phase space of a system of differential equations: different mathematical registers

We describe and analyze a situation involving symbolic representation and graphical visualization of the solution of a system of two linear differential equations, using a computer algebra system. Symbolic solution and graphical representation complement each other. Graphical representation helps to understand the behavior of the symbolic solution. Together with it, the symbolic solution and its analysis are needed to understand the graphical representation and to overcome the limiting constraints of the CAS. The study described in this paper points out the importance of flexibility in building connections between different mathematical registers, together with the fact that the balance between the usage of symbolic representations and of graphical representations can be very different from one student to the other. Research supported by Israel Science Foundation, grant number 1340/05.     

中大班幼儿统计数据表征能力的发展

以上海市两所幼儿园的120名中班和大班幼儿为被试考察幼儿统计数据表征能力的发展时发现:(1)中大班幼儿的统计数据表征可分为四种类型,分别是图画型、数字型、图文结合型和初级图表型,每种类型各可分为五个发展水平。(2)随着年龄的增长,幼儿对统计数据的表征类型从数字型、图画型逐渐向图文结合型和初级图表型过渡。     

Protein sequence analysis based on hydropathy profile of amino acids

Biology sequence comparison is a fundamental task in computational biology. According to the hydropathy profile of amino acids, a protein sequence is taken as a string with three letters. Three curves of the new protein sequence were defined to describe the protein sequence. A new method to analyze the similarity/dissimilarity of protein sequence was proposed based on the conditional probability of the protein sequence. Finally, the protein sequences of ND6 (NADH dehydrogenase subunit 6) protein of eight species were taken as an example to illustrate the new approach. The results demonstrated that the method is convenient and efficient.     

A study regarding the spontaneous use of geometric shapes in young children’s drawings

The studies regarding how the comprehension of geometric shapes evolves in childhood are largely based on the assessment of children's responses during the course of tasks linked to the recognition, classification or explanation of prototypes and models. Little attention has been granted to the issue as to what extent the geometric shape turns out to be an expressive tool that young children spontaneously use in their pictorial productions and also, whether or not methodological research approaches aimed at the examination of unprompted usage of geometric shapes in childhood may be useful regarding the study of the development of geometric thinking. This evidence provided by this study is coherent with the assumption that before starting primary education, internal representation of closed curves, quadrilaterals and triangles should have been developed by a significant number of children and, more interestingly, that young children’s graphical expressivity appears liaised to their skill to depict two-dimensional geometric shapes.     

基于“引入工程项目”教学法的工程制图课程教学改革

应用"引入工程项目"教学法于工程制图课程中,构建新的理论教学体系和实践教学体系,针对不同的教学单元将制图理论与实践进行有机融合,将课程目标具化为认知目标、情感目标、技能目标,使学生快速建立从三维物体构形到二维图形表达、再到三维物体重构的知识架构,将工程知识不断融入自己的学习背景,促进学生对知识的理解和掌握.     

构建三维参数空间区分完全基因组中的编码和非编码序列

发现编码序列和非编码序列中有明显的尺度联系的存在性会给弄清DNA序列带来新的前景,这就促使我们去寻找新的方法来描述和区分编码和非编码序列。在这篇文章中,首先采用数值序列来表示DNA序列,然后以多重仿射性分析和Holder指数形式来得到三个指数,并以此构建参数空间。每个编码或非编码序列就被表示为这个三维参数空间之中的一个点。在这个参数空间中,完全基因组中的编码序列和非编码序列被粗略地分开到两个不同的区域。     

An Expected Response Function Approach to Graphical Differential Item Functioning

In this paper a new approach to graphical differential item functioning (DIF) is offered. The methodology is based on a sampling-theory approach to expected response functions (Lewis, 1985; Mislevy, Wingersky, & Sheehan, 1994). Essentially error in item calibrations is modeled explicitly, and repeated samples are taken from the posterior distributions of the item parameters. Sampled parameter values are used to estimate the posterior distribution of the difference in item characteristic curves (ICCs)for two groups. A point-wise expectation is taken as an estimate of the true difference between the ICCs, and the sampled-difference functions indicate uncertainty in the estimate. Tbe approach is applied to a set of pretest items, and the results are compared to traditional Mantel-Haenszel DIF statistics. The expected-response-function approach is contrasted with Pashley's (1992) graphical DIF approach.     

The Status of Graphical Presentation in Interior/Architectural Design Education

This article argues that interior/architectural design education favours a dominance of final presentation over the design process in the studio environment, particularly in the evaluation of a project. It suggests that the appeal of design juries for pleasant drawings, which may shift the emphasis from the project itself to its representation, may be recognized as a discursive habit with limited contribution for educational concerns. The theoretical stance argues that the interest for graphical presentation has primarily remained within a formalist aesthetic agenda and has rarely been conceptualized beyond this convention. With this in mind a series of questions is developed in order to reform the relationship between graphical presentation and the design education process.