Effect of Splice Marking on Fabric Roll Planning

Minimising the fabric loss during spreading can reduce the total production costs of garment manufacturing. Although marker planning is a major determinant of material utilisation, considerable savings on materials also will be made from the area of spreading loss. In the spreading process, it is general to have variance on the fabric yardage between each fabric roll, and the number of splice markings on each cutting lay is also varied. This paper aim to study how the fabric roll planning and the number of splice marks of a cutting lay will affect the material usage in the spreading process. By using a genetic algorithm approach, the amount of fabric to be saved by optimising the fabric roll sequence was derived by comparing the best arrangement and the worst arrangement of the fabric roll sequences of a cutting lay. The result of the study showed that both fabric roll planning and the number of splice marking have effect on the fabric loss. The findings could help the apparel manufacturer to reduce the     

几何平均亚式期权的定价方法

亚式期权有两种理论上的表示方式,即采用算术平均法计算资产价格的平均值和采用几何平均法计算资产价格的平均值,实际应用中多以算术平均法计算资产价格的平均值,但很难求得其精确的解析定价公式,采用几何平均法计算资产价格的平均值,并以连续时间的情形为例,得到了亚式期权的解析定价公式。     

Investigation on the Dimensional Properties of Relaxed Plain Knitted Fabrics

A geometric model of relaxed plain-nitted fabric isproposed.A method based on the model for predictingthe loop length from the course spacing,wale spacing offabric and the diameter of yarn is deduced,as well as a computer program is developed to graphically represent the structures of plain knitted fabric with various struc-tural parameters.     

随机的算术几何平均

本文证明了在Ｂｅｔａ随机分布权重下,Ｌａｇraｎｇｅ和Ｌｅｇｅｎｄｒｅ两种算术几何平均的几乎处处收敛性,讨论了两种算术几何平均的一些性质。     

A New Method for Measuring the Stitch Length of Weft Knitted Fabric in a Static Environment

It is essential to measure the stitch length of weft knitted fabric in a static environment for economy and improving productivity. The image inputted was dealt with the digital image processing techniques： the paper carried out the transformation of grey scale; then removed impurities with filtering; the characteristic of the stitch structure was abstracted by using the Fourier transform technique. To obtain the stitch length more accurately, we should establish ageometric medal of the stitch lined on the digital image processing, which provides a way to transform the stitch length in the two-dimenslon space into a three-dimension space. This study provides a new methed for measuring the stitch length without damaging the fabric.     

周期等差函数与周期等比函数

周期性是函数的一种特殊而重要的性质,在函数的研究中占有重要的地位.函数的周期等差性和周期等比性是将周期性与等差性及等比性结合而得到的,这些性质对函数的研究将提供一定的帮助.     

基于熵编码CABAC的信源信道联合解码器

H.264的熵编码都采用基于上下文自适应二进制算术编码（CABAC）,能达到较高的压缩性能,但对信道误码非常敏感.文中提出了一种基于CABAC的算数码变长码联合解码算法,联合信源信道算数码解码之后的信息作为变长码的输入信息,再通过变长码格状图搜索获得最佳的符号序列.同时,在算数码解码部分可以利用变长码的码字结构信息来删除无效搜索路径,提高解码性能.仿真实验表明,该联合迭代解码算法明显优于传统的分离解码器.     

Theoretical Analysis of the Factors Affecting Splice Loss During Fabric Spreading

Material utilization is mainly concerned by industrialpractitioners since it contributes to minimize the totalproduction costs for garment manufacturing. Apart fromthe marker loss, splice loss (the fabric loss during thejoining of different fabric rolls) is one of the primarycauses of fabric loss, but it has not been considered spe-cifically in the past literatures. The amount of splice lossduring fabric spreading is governed by various factors in-cluding the marker length, the number of fabric rolls,and the number of splicing intervals for laying-up. Inour study, these three effects on splice loss during fabricspreading were computed and analysed.     

浅探算术-几何均值不等式在不等式证明中的应用

均值不等式是数学中几个经典不等式之一,在生产和生活中具有重要作用,是证明不等式及求解各类最值问题的一个重要依据和方法。其中算术一几何均值不等式应用曩为广泛,具有变通灵活性和条件约束性等特点,在不等式证明方面具有不可怠视的作用。本文分别从内容的突破和形式的构造两个方面,探索算术一几何均值不等式在不等式证明中的应用。     

Rough正项几何规划及其算法

在rough集合和rough凸集的基础上,提出了rough值集凸函数的概念,建立了rough正项几何规划的知识表示模型、数学模型.此外,研究了rough正项几何规划的数学模型,以及解决多反而少的"悖论"的rough 正项几何规划的算法,它可以化为一单项rough正项几何规划后再化为一个rough线性规划来求解.最后,通...     

Imitation of Fabric Flagging Based on Amplitude Modulation

A model-independent 3 - D texture synthesis ofphysical and stochastic algorithms, based on an amplitudemodulation method, is presented to realize 3 - D fabricdynamic simulation. The physical functions are built tosimulate fabric basic deformation. The stochasticfunctions, generated by Perlin noise, are used to simulatefabric natural motion in the wind. The two kinds offunctions are synthesized by method of amplitudemodulation. As the arithmetic uses stochastic functions instead of recursive algorithm, it is capable of simulating thefabric material, the wind force and direction in real-time.Given the fabric material and wind strength, thestochastic functions can be created to simulate fabricmotion in the wind and this model can be adjusted bycontrolling some certain parameters to achieve a goodsimulation effect. This method is conceptually intuitive,computationally fast and efficient. Furthermore, thecombination of fabric physical and statistic motioncharacteristics provides an attractive way to improve thedisplay effect and rate.     

用微积分求数列的前n项和

等差、等比数列的前n项和易求,而一般数列的前n项和是不太容易求的,本文介绍利用微积分知识求数列的前n项和公式的一些方法,并给出一些结论。     

关于有穷等差数列的一个性质

得到从有穷等差数列中可重复地任取3项和，所有不相等的和数构成等差数列，公差与原数列相同，进而得到各项出现的频数分布，据此可解决一类用穷举法极为繁琐的古典概率问题。     

两种修正判断矩阵一致性方法的比较分析

对层次分析中判断矩阵一致性的修正方法进行了研究，证明了修正判断矩阵一致性的加权算术平均法的收敛性，并同时加权几何平均法进行了详细的比较。理论分析表明：虽然这2种方法都具有收敛性，且均可对一致性较差的判断矩阵进行修正，但加权几乎平均法比加权算术平均法简洁，且前者无需通过转换，直接保持了修正后的判断矩阵的互反性。数值结果也显示：加权几何平均法所需的迭代次数比加权算术平均法所需迭代次数少。     

55g/m2平纹水刺非织造布的工艺探讨

对55 g/m2平纹水刺非织造布的整个工艺技术路线进行分析,并对其中最重要的两道工序梳理成网和水刺固结中的关键工艺参数采用正交试验进行详细分析,从而得出55 g/m2平纹水刺非织造布的最佳生产工艺,为开发该类产品提供依据.     

M序列报文的MIAC压缩编码算法

M序列报文是典型短波数据链报文。提出一种针对M序列报文的MIAC压缩编码算法,该算法根据M序列报文的统计特性,应用基于字段结构的半动态概率估计模型,量化低概率符号出现概率的取值且半动态更新,采用动态的编码区间长度更新机制,使乘法运算替换为预处理过程中的查表运算,最大造成10.04%的编码效率损失。测试结果表明,当M序列报文数目为2~9条时,MIAC压缩编码算法在损失最多20%的压缩率时,使压缩时间低于原算术编码至少50%。为今后研究提升数据链系统性能提供一种新的思路。     

Cloth Modeling Based on Particle System

A physical-based particle system is employed for cloth modeling supported by two basic algorithms, between which one is the construction of the internal and external forces acting on the particle system in terms of KES-F bending and shearing tests, and the other is the collision algorithm of which the collision detection is carried by means of bi-section of time step and the collision response is handled according to the empirical law for frictionless collision. With these algorithms, the geometric state of particles can be expressed as ordinary differential equations which is numerically solved by fourth order Runge-Kutta integration. Different draping figures of cotton fabric and wool fabric prove that such a particle system is suitable for 3D cloth modeling and simulation.     

Kevlar布层间及钢板单搭接黏结性能的试验研究

为了研究Kevlar纤维布层间以及纤维布与钢板单搭接的黏结性能,利用MTS微机控制电子万能试验机,分别对双层Kevlar 49纤维布和Kevlar 49纤维布/钢板单搭接剪切接头的力学性能进行测试.结果表明,双层Kevlar 49纤维布、Kevlar 49纤维布/钢板单搭接剪切接头试样的有效黏结长度分别为25mm和50mm.在有效黏结长度范围内,两种单搭接接头的黏结力均随着黏结长度的增加而增加,但增加幅度逐渐减小,当达到有效黏结长度时,黏结力达到最大值;黏结应力随着黏结长度的增加逐渐降低.本研究结果为土木工程结构补强所用Kevlar纤维布的合理黏结长度提供参考数据.     

织物起拱第一报:主观评价和心理物理标度

美观是消费者日常服装穿着功能中最重要的指标之一.起拱是一种外衣穿着中引起变化,令人不满的三维残余变形.一种主观评价方法是从一系列起拱织物的照片来理解心理物理学规律,采用优劣排序等级和优劣评判等级两种方法用于心理评价标度.这两种等级互相间紧密相关,但评判等级比排序等级包含更多的信息,可以更好地区分出两种织物间的差异.主观评价结果与测量得到的残余起拱高度之间线性相关,表明了织物起拱特性符合斯特藩指数定律.残余起拱高度对织物起拱特性总方差的贡献在94%以上.其它可能是起拱时各向异性因素引起的.     

使用二次和几何不等式导出交互熵问题

考虑带二次约束和交互熵约束的最小二次规划和交互熵问题．基于二次和几何不等式的理论与性质，导出了上述两个规划原问题的对偶规划．进一步，由不等式中等式成立时的性质建立了两个原始一对偶规划的对偶定理和Kuhn—Tucker条件。