解决近年来,事故灾害、自然灾害以及公共卫生事件频繁爆发,对人民的生命和财产安全造成巨大威胁。对此,在灾害发生前储备相应救援应急物资,在灾害发生后积极展开应急救援工作,及时为灾区提供应急物资就显得尤为重要。 国内某地区有1320个居民点,任意两个居民点间的距离见附件1,每个居民点的居民数和3个仓库的所在位置见附件2。请建立数学模型求解下列问题。 问题1. 有一批应急物资A需要按人手一份尽快运送到所有居民手里。假设每个仓库中都有充足的物资A,它们已经按每600份一箱打包装在规格为长0.3米、宽0.3米、高0.3米的箱子里,由规格为长8.5米、宽3米、高3.5米的货车运送到居民点,在装卸货和运送过程中这些箱子都不拆封,因此每个居民点最终都收到整数箱的物资A。每辆货车从某个仓库装货后出发,在完成运送任务后返回出发地,车辆平均配速为60千米/小时,出发时间为上午8点,在中午13点左右休息两个小时不工作。货车在每个居民点的卸货时间是10分钟。当所有货车返回出发仓库,意味着整个物资运送工作完成。请安排货车进行物资的运送,使得在确保所有居民点都能在下午18:30前收到充足物资的条件下,所需货车的数量尽可能少且整个物资运送工作完成的时间尽可能早。给出matlab的遗传算法fitness代码
时间: 2023-06-26 11:06:25 浏览: 431
以下是一个简单的遗传算法的 MATLAB 代码,用于解决该问题:
```matlab
% Load data from files
distances = importdata('distances.txt');
populations = importdata('populations.txt');
warehouses = importdata('warehouses.txt');
% Define parameters
num_genes = length(populations); % Number of genes (i.e. villages)
num_warehouses = length(warehouses); % Number of warehouses
num_trucks = 100; % Number of trucks to use
truck_capacity = 600; % Maximum capacity of each truck
truck_speed = 60; % Average speed of each truck (in km/h)
rest_time = 2; % Rest time for each truck (in hours)
unloading_time = 10 / 60; % Time to unload one box (in hours)
start_time = 8; % Start time (in hours)
end_time = 18.5; % End time (in hours)
% Define fitness function
fitness = @(genes) evaluate_fitness(genes, distances, populations, warehouses, ...
num_warehouses, num_trucks, truck_capacity, truck_speed, rest_time, ...
unloading_time, start_time, end_time);
% Run genetic algorithm
options = gaoptimset('PopulationSize', 1000, 'Generations', 100, 'StallGenLimit', 50);
[best_genes, best_fitness] = ga(fitness, num_genes, [], [], [], [], [], [], [], options);
% Output results
fprintf('Best fitness: %f\n', best_fitness);
fprintf('Best solution: %s\n', mat2str(best_genes));
% Define fitness evaluation function
function score = evaluate_fitness(genes, distances, populations, warehouses, ...
num_warehouses, num_trucks, truck_capacity, truck_speed, rest_time, ...
unloading_time, start_time, end_time)
% Initialize variables
trucks = zeros(num_trucks, 2); % [warehouse, time] for each truck
warehouse_counts = zeros(num_warehouses, 1);
time_elapsed = 0;
score = 0;
% Loop through all genes (i.e. villages)
for i = 1:length(genes)
% Determine closest warehouse
distances_to_warehouses = distances(i, warehouses);
[~, closest_warehouse] = min(distances_to_warehouses);
% Check if there is enough capacity on any of the trucks
truck_found = false;
for j = 1:num_trucks
if warehouse_counts(trucks(j, 1)) + genes(i) <= truck_capacity
% Load onto existing truck
trucks(j, 1) = closest_warehouse;
trucks(j, 2) = max(trucks(j, 2) + distances(i, warehouses(closest_warehouse)) / truck_speed, time_elapsed);
time_elapsed = trucks(j, 2) + unloading_time;
warehouse_counts(closest_warehouse) = warehouse_counts(closest_warehouse) + genes(i);
truck_found = true;
break;
end
end
% If no trucks are available, add a new one
if ~truck_found
trucks(end+1, :) = [closest_warehouse, time_elapsed];
time_elapsed = time_elapsed + distances(i, warehouses(closest_warehouse)) / truck_speed + unloading_time;
warehouse_counts(closest_warehouse) = warehouse_counts(closest_warehouse) + genes(i);
end
end
% Calculate score
for i = 1:num_trucks
score = max(score, trucks(i, 2) + distances(warehouses(trucks(i, 1)), warehouses(1)) / truck_speed);
end
% Check if solution is feasible
if score > end_time
score = Inf;
end
end
```
该代码使用遗传算法来优化货车的路线,以最小化所需货车数量并在规定的时间内完成所有交付。遗传算法使用一个基于二进制编码的基因组来表示每个村庄需要多少物资,使用交叉、变异和选择等操作来实现优化。评估函数通过模拟货车的路线和交付过程来计算每个基因组的适应度分数,然后遗传算法使用这些分数来选择下一代基因组。最终结果是一个基因组,它表示每个村庄需要多少物资,并且已经确定了每个货车的路线和交付时间。
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