These algorithms also include the terrain texture generation algorithms and the frustum culling algorithms . the mathematic model of flight simulation was discussed in chapter four . in chapter five 这一章还介绍了地形纹理的生成算法，视图平截头体选取算法，这些算法使得计算机可以用来处理大规模的可视化工作。
Pointing to this problem , a numerical simulation was firstly carried out , and then some measures was taken to prevent the equator from wrinkling by slightly changing the shape of the frustum shell , as a result , the bulged vessel became more round 针对这一问题，对其胀形过程进行了有限元数值模拟，并通过改变圆锥台的初始形状，来保证容器的圆度和避免赤道处的失稳起皱。
Due to the complexity of the load combinations of the gate chamber , it is difficult to perform such test on each load case . on the other hand , it is lack of the test data on the load case perpendicular to the current direction of the gate frusta till now 由于闸室的受力荷载组合较为复杂，对每种工况都做光弹试验不容易做到，且有关垂直水流方向的闸墩受力状况的试验资料迄今尚很缺乏。
On the process of simulation the deformation after excavation at the middle frusta and the vertical slope at three gorges permanent shiplock , program the fortran procedure to perfect model creation and the capability of the pre - procedure and post - procedure in flac - 3d 在模拟三峡永久船闸中隔墩和直立边墙开挖卸荷变形过程中，编制fortran程序，完善flac - 3d建模功能和增强其前后处理能力。
Traditionally , loads of the arc gate are applied on the support or gate frusta as a set of concentrated load , but the effect range of such load on the frusta cannot be solved by material mechanics and structure mechanics . most of the load cases are fulfilled through optic - elastic test 通常弧门荷载作为一组集中荷载作用于牛腿或闸墩上，而这组荷载对闸墩受力的影响范围材料力学方法和结构力学方法是不能解决的，受力状况大部分是通过光弹试验完成。
Two numerating methods are used in traditional structural design of gate chamber . first , considering the gate frusta to be fastened on the weir body , it is calculated as plane stress problem independently . then applying the results ( moment and vertical force ) on the bottom of gate frusta as concentrating load on the weir body , and the weir body is viewed as a elastic foundation beam or plate and unilateral stress analysis was performed 传统闸室结构计算有两种计算方法，其一是将闸墩视为固端于堰体上，单独进行闸墩平面受力计算，再将闸墩下部的计算结果(弯矩和垂直力)作为集中荷载作用于堰体上，堰体作为弹性地基梁或板进行片面应力计算。
( 6 ) 3d integer model of spillway and frusta of brake are established and numerical computation of 3d viscous flow over spillway is completed . the influence of frusta of brake for design parameters such as shape of free surface , pressure on dam , flux coefficient is computed aim at type of frusta of brake and disposal on dam and compute result of different type of frusta and disposal model is compared 6 )通过建立溢流坝和闸墩的三维整体模型，完成了对三维过坝水流粘流场的数值计算，针对闸墩的型式及在坝面的布置计算了闸墩对水面线形状、坝面压力、流量系数等设计参数的影响，并将不同墩型与布置形式的计算结果进行比较。
The result show that the position of free surface is higher because of frusta of brake , especial obvious in the head of frusta of brake ; flux coefficient and pressure on dam are quite influenced by type of frusta and 3 a type frusta of brake relative to 2 type frusta of brake has bigger flux coefficient and smaller pressure on dam ; obvious influence of ability of discharge flow for different ratio of thickness of frusta and breadth of brake and pressure on dam reduces with increasing ration of thickness of frusta and breadth of brake , while bigger flux coefficient is obtained when tlb = 0 . 2 结果表明，闸墩河海大学博士论文的存在抬高了水面线的位置，其中在闸墩头部尤其明显;墩型对流量系数和坝面压力影响较大， 3a型闸墩相对于2型闸墩具有更大的流量系数和更小的坝面压力:不同的墩厚闸宽比t / b对泄流能力也将产生显著的影响，随着墩厚闸宽比的增加，坝面压力降低，而当t / b二0 . 2时溢流坝具有更大的流量系数。
By finding the big penetrating crack in wangpu aqueduct upper frusta structure , the task group has adopted the integrated measures of chemical perfusion , carbonized fibre reinforcement and doping external surfaces to effectively reinforce the work , and improved the reinforcing techniques considering the characteristic of hydraulic engineering , made remarkable benefit in social , economic aspects 摘要针对王铺渡槽上部墩柱结构出现的大开度贯穿性裂缝，经过全面分析和多方案综合对比，采用裂缝化灌、碳纤维加固、外表面刷涂水性环保型乳胶漆外墙涂料作为防护的综合措施对原工程进行有效的加固处理，并结合水利工程的自身特点改进了加固技术工艺，取得了显著的经济和社会效益。
Through the study and analysis conclude as follows : in human dna sequences , if the distinction of the number of the four bases is very small , they can distribute in a sphere whose radius equal to 1 / 4 ; if the distinction of them is comparative large , they can distribute between the sphere and the frustum - octahedron ; if one is 0 in them , they can distribute between the frustum - octahedron and regular - octahedron ; if the distinction of them is especial large , they may distribute in the outer of the regular - octahedron 通过研究和分析得到结论为：在人类dna序列中，如果四个碱基的数目相差很小时，它们可能分布在半径为1 / 4的球内；如果相差比较大时，它们可能分布在这个球和截角八面体之间；如果在四个碱基数目中有一个为零时，那么它们有可能分布在截角八面体和正八面体之间；如果相差的特别大，甚至有可能落在那个正八面体的外部。
