PROBLEM A: Positioning and Moving Sprinkler Systems for Irrigation $ X( U" Y+ j5 V7 T! SThere are a wide variety of techniques available for irrigating a field. The technologies range from advanced drip systems to periodic flooding. One of the systems that is used on smaller ranches is the use of "hand move" irrigation systems. Lightweight aluminum pipes with sprinkler heads are put in place across fields, and they are moved by hand at periodic intervals to insure that the whole field receives an adequate amount of water. This type of irrigation system is cheaper and easier to maintain than other systems. It is also flexible, allowing for use on a wide variety of fields and crops. The disadvantage is that it requires a great deal of time and effort to move and set up the equipment at regular intervals. Given that this type of irrigation system is to be used, how can it be configured to minimize the amount of time required to irrigate a field that is 80 meters by 30 meters? For this task you are asked to find an algorithm to determine how to irrigate the rectangular field that minimizes the amount of time required by a rancher to maintain the irrigation system. One pipe set is used in the field. You should determine the number of sprinklers and the spacing between sprinklers, and you should find a schedule to move the pipes, including where to move them. A pipe set consists of a number of pipes that can be connected together in a straight line. Each pipe has a 10 cm inner diameter with rotating spray nozzles that have a 0.6 cm inner diameter. When put together the resulting pipe is 20 meters long. At the water source, the pressure is 420 Kilo- Pascal’s and has a flow rate of 150 liters per minute. No part of the field should receive more than 0.75 cm per hour of water, and each part of the field should receive at least 2 centimeters of water every 4 days. The total amount of water should be applied as uniformly as possible. 2 i1 ?" u6 u! n# ~ / C, W' |! R7 V7 x: }* T& W0 l # A0 R; ?& j/ c( g7 {# B7 x- W& J4 k9 x: I , Q! ?" O* S5 L2 g) [3 N- y. d ; m. g v4 l5 n z6 `! T; x A 题: 灌溉喷洒系统的布置与移动问题 ; [& _, o! \9 K" K% y0 y8 M s. k: U目前有很多种田间灌溉的技术. 从先进的滴灌系统到周期性的漫灌等各种技术. 用于较小农场的技术之一就是使用“手动”灌溉系统. 带有喷头的轻质铝管放置在田间, 定时用手移动它们以确保所有农田都能够得到充足的水. 这种灌溉系统比其他系统更加便宜, 更加容易管理、维护. 它们的使用非常灵活,可用于各种农田和农作物的灌溉. 其缺点是,每过一段时间, 就要花费很多时间和精力来移动和安装设备. 考虑到要使用这种灌溉系统, 怎样安装才能用最少的时间去灌溉一片80 米×30 米的农田? 为完成这项任务, 请求你们去寻求一种确定怎样灌溉这块矩形农田使得农场主管理、维护该灌溉系统所需要的时间最少. 这块农田上将使用一套管组. 你们需要确定喷头的数量以及喷头之间的距离, 同时还要给出一个移动管道, 包括需要把管道移动到什么位置的工作进度表. 一套管组由若干互相连接成直线形的管子组成. 每根管子的内壁直径为10 厘米,并带有一个内壁直径0.6 厘米的可旋转喷嘴. 把管子连接在一起, 其总长为20 米长. 水源处的压力为420 千帕(Kilo-Pascal), 流率为每分钟150 升. 农田任何部分接受的水量不得超过每小时0.75 厘米, 同时农田的每个部分每4 天至少要接受2 厘米的水量. 尽可能均匀地使用洒水的总量.