This thesis briefly analyzes some yield criteria and instability criteria to the sheet metal forming first . then according to the transformation rule from ultimate strain to ultimate stress , it establishes the mathematical calculation models of the forming limit stress diagram for the software development according to hill48 、 hill79 and hosford yield criterion irrespectively 本文首先分析了板料成形的屈服准则和失稳准则,然后根据极限应变到极限应力的转换关系,分别采用hill48屈服准则、 hill79屈服准则和hosford屈服准则,建立了用于软件开发的成形极限应力图的数学计算模型。
Because there is a large mount of random numbers produced with certain probability distribution in the process of monte - carlo simulation , the use of computer is necessary . this paper utilizes the matlab " s strong function in mathematical calculation to produce the random numbers and complete the whole process of simulation , instead of traditional program language 蒙特卡罗模拟由于需要产生大量具有一定概率分布的随机数，必须借助于计算机实现该过程，本文利用matlab软件强大的数学计算功能，代替传统的编程语言产生随机数，并应用该软件编程完成了整个模拟过程。
R extracts remote sense information and conventional information to establish special analysis information system about water resource in longkou city which includes special database and attributive database ~ based on the analysis of database , ten water resource mathematical calculation models have been set up , i . e . precipitation , runoff , groundwater , evaporation , discharge , utilizable water resources degree , industry and living with horton geomorphology and g theory 提取遥感信息和常规信息，建立龙口市水资源时空分析基础数据库，包括空间数据库和属性数据库。基于基础数据库的分析，以horton地貌律和g理论为指导，建立降水量、径流、地下水、蒸发量、水资源可利用量、工农业及生活用水量等十种水资源数学计算模型，即构建起模型库。
Aiming at the problem that the seeds picked up by the suction plate of the seed metering device cannot accurately fall into the seed pit opener as well as into the seed pit , an innovated seed metering device on which the seed dropping angle can be adjusted within a certain range and a new testing stand have been developed in accordance with the mathematical calculation model that had " in accordance with the mathematical calculation model that had been established previously . then an experimental study is conducted and the seed dropping law has been found out through the study 本论文根据2bqm - 2型气吸式精量铺膜播种机的结构和工作原理，针对该机在实际播种中，吸种盘吸出的种子不能满足准确地落入在膜上滚动开穴的鸭嘴内，并及时地排入到鸭嘴所成的穴孔内的设计要求，进行了一定的试验研究，利用已建立的计算数学模型，设计新的试验台，改进排种器，使排种器的落种角度可以在一定的范围内调整。
From japans independence for the game , it let the whole country crazy , as the rules simple , yet nimble , considering among absolutely no need to apply mathematical calculations , the only logical reasoning ability , the young and middle - aged men and women both young and old . everybody can play 源于日本的“数独游戏” ，目前让英国举国为之疯狂，由于规则简单，却变化无穷，在推敲之中完全不必用到数学计算，只需运用逻辑推理能力，所以无论老少中青男女，人人都可以玩。
There are two stages in isc : in the first stage the robot explores along the boundary of the environment , and in the second stage the robot plans the coverage path on line . by repeat covering some grids and setting the gate grids it not only guarantees the complete coverage , but also reduces the coverage repetition , thus improves the efficiency . there are no complex mathematical calculations in the planning which can meet the requirement of real - time and is fit for the embedded system Isc算法通过边界探索获得环境边界地图,之后在线规划覆盖路径,通过对部分栅格的重复覆盖和设置gate栅格保证了完全覆盖所有区域,而且也降低了重复覆盖率,提高了工作效率,同时该算法不用进行复杂的数学计算,保证了算法的实时性,降低了对内存的需求,适合于嵌入式软件。
Author , secondly , starts from the approximate expandness of square root operator , perform mathematical calculations for finite difference operator in frequency - space domain , fourier finite difference operator in mixing domain ( frequency - space and frequency - wavenumber domain ) and general screen operator in mixing domain , compare and discuss their precision of their wavefield , adaptability for lateral velocity variations , computation efficiency and stability . thirdly , author , applies the steady variational reference slowness rytov approximation general screen wavefield extrapolation operator ( vrselrf ) in frequency - wavenumber domain , to the prestack and poststack forward modeling and depth migration 第二，从平方根算子的近似展开出发对频率?空间域的有限差分算子、混合域(频率?空间域；频率?波数域)的fourier有限差分算子、混合域的广义屏算子进行了推导并对其波场描述精度、对横向变速的适应性、计算效率和稳定性进行了比较与评述。
