【Scopus/Springer Nature/Google Scholar/EI/Scopus多库收录】2025年8-9月先进制造、信号处理、土木工程、环境资源、能源材料、教育技术领域的创新前沿
import numpy as np
def genetic_algorithmoptimize(tool_paths, population_size=50, generations=100, mutation_rate=0.01):
# 初始化种群
population = np.random.permutation(tool_paths)
for generation in range(generations):
# 计算适应度(路径长度)
fitness = np.array([sum(np.abs(path[:-1] - path[1:]).sum(axis=1)) for path in population])
# 选择
parents = population[np.argsort(fitness)[:population_size//2]]
# 交叉
offspring = np.empty_like(parents)
for i in range(len(parents)//2):
parent1, parent2 = parents[i], parents[len(parents)-1 -i]
crossover_point = np.random.randint(1, len(parent1)-1)
offspring[2*i] = np.concatenate([parent1[:crossover_point], parent2[crossover_point:]])
offspring[2*i +1] = np.concatenate([parent2[:crossover_point], parent1[crossover_point:]])
# 变异
for i in range(len(offspring)):
if np.random.rand() < mutation_rate:
swap_indices = np.random.randint(0, len(offspring[i]), 2)
offspring[i][swap_indices[0]], offspring[i][swap_indices[1]] = offspring[i][swap_indices[1]], offspring[i][swap_indices[0]]
population = np.concatenate([parents, offspring])
# 返回最优路径
fitness = np.array([sum(np.abs(path[:-1] - path[1:]).sum(axis=1)) for path in population])
return population[np.argmin(fitness)]
# 示例:优化数控加工路径
tool_paths = np.random.randint(0, 100, (10, 2)) # 随机生成刀具路径点
optimized_path = genetic_algorithmoptimize(tool_paths)
print("优化后的加工路径:\n", optimized_path)
import numpy as np
import matplotlib.pyplot as plt
def fft_analysis(signal, sample_rate):
n = len(signal)
fft_result = np.fft.fft(signal)
freqs = np.fft.fftfreq(n, 1/sample_rate)
magnitudes = np.abs(fft_result)
return freqs, magnitudes
# 示例:分析混合正弦信号
sample_rate = 1000 # 采样率
t = np.linspace(0, 1, sample_rate) # 时间数组
signal = np.sin(2*np.pi*50*t) + 0.5*np.sin(2*np.pi*120*t) # 混合50Hz和120Hz信号
freqs, magnitudes = fft_analysis(signal, sample_rate)
plt.figure()
plt.plot(freqs[:len(freqs)//2], magnitudes[:len(magnitudes)//2])
plt.xlabel('频率 (Hz)')
plt.ylabel('幅度')
plt.title('信号频谱分析')
plt.show()
from scipy.optimize import minimize
def concrete_mix_design(target_strength, materials_cost, constraints):
# 定义目标函数(最小化成本)
def cost(x):
return materials_cost @ x
# 定义约束条件(强度要求等)
cons = [{'type': 'ineq', 'fun': lambda x: target_strength - (x[0]*10 + x[1]*5 + x[2]*3)}, # 强度约束示例
{'type': 'eq', 'fun': lambda x: x.sum() - 1}] # 总比例约束
# 最小化成本
result = minimize(cost, np.ones(len(materials_cost))/len(materials_cost), constraints=cons, bounds=[(0,1)]*len(materials_cost))
return result.x
# 示例:优化混凝土配合比
target_strength = 30 # 目标强度 (MPa)
materials_cost = np.array([100, 80, 60]) # 水泥、砂、石子的成本
constraints = [{'type': 'ineq', 'fun': lambda x: x[0] - 0.2}, # 最小水泥比例
{'type': 'ineq', 'fun': lambda x: 1 - x[0]}] # 最大水泥比例
optimal_mix = concrete_mix_design(target_strength, materials_cost, constraints)
print("优化后的混凝土配合比(水泥、砂、石子):", optimal_mix)
import numpy as np
from sklearn.metrics.pairwise import cosine_similarity
def cf_recommendation(user_item_matrix, user_id, top_n=5):
# 计算用户相似度
user_similarities = cosine_similarity(user_item_matrix)
# 获取目标用户的相似用户
similar_users = np.argsort(user_similarities[user_id])[::-1][1:top_n+1]
# 预测目标用户对未交互项目的评分
user_item_mean = user_item_matrix.mean(axis=1)
ratings_diff = (user_item_matrix - user_item_mean[:, np.newaxis])
pred_ratings = user_item_mean[user_id] + np.dot(user_similarities[user_id, similar_users], ratings_diff[similar_users]) / np.sum(np.abs(user_similarities[user_id, similar_users]))
# 推荐评分最高的项目
recommended_items = np.argsort(pred_ratings)[::-1][:top_n]
return recommended_items
# 示例:学生学习资源推荐
user_item_matrix = np.array([[5, 3, 0, 1], [4, 0, 0, 1], [1, 1, 0, 5], [1, 0, 0, 4], [0, 1, 5, 4]])
user_id = 0 # 目标用户ID
recommended_items = cf_recommendation(user_item_matrix, user_id)
print("推荐的学习资源索引:", recommended_items)