We present an integrated prediction-optimization (PredOpt) framework to efficiently solve sequential decision-making problems by predicting the values of binary decision variables in an optimal solution. We address the key issues of sequential dependence, infeasibility, and generalization in machine learning (ML) to make predictions for optimal solutions to combinatorial problems. The sequential nature of the combinatorial optimization problems considered is captured with recurrent neural networks and a sliding-attention window. We integrate an attention-based encoder-decoder neural network architecture with an infeasibility-elimination and generalization framework to learn high-quality feasible solutions to time-dependent optimization problems. In this framework, the required level of predictions is optimized to eliminate the infeasibility of the ML predictions. These predictions are then fixed in mixed-integer programming (MIP) problems to solve them quickly with the aid of a commercial solver. We demonstrate our approach to tackling the two well-known dynamic NP-Hard optimization problems: multi-item capacitated lot-sizing (MCLSP) and multi-dimensional knapsack (MSMK). Our results show that models trained on shorter and smaller-dimensional instances can be successfully used to predict longer and larger-dimensional problems. The solution time can be reduced by three orders of magnitude with an average optimality gap below 0.1%. We compare PredOpt with various specially designed heuristics and show that our framework outperforms them. PredOpt can be advantageous for solving dynamic MIP problems that need to be solved instantly and repetitively.

我们提出了一个集成的预测-优化（PredOpt）框架，通过预测二进制决策变量在最优解中的值，高效地解决顺序决策问题。我们通过循环神经网络和滑动注意机制捕捉组合优化问题的顺序特性，并将基于注意力的编码器-解码器神经网络架构与消除不可行性和泛化框架相结合，以学习高质量的适用于时间相关优化问题的可行解。我们的结果表明，可以成功地使用在较短和较小维度实例上训练的模型来预测更长更大维度的问题。优化解决时间可缩短三个数量级，平均最优性差距小于0.1%。我们将PredOpt与各种专门设计的启发式方法进行比较，并证明我们的框架表现优于它们。PredOpt对于需要立即且重复求解的动态MIP问题具有优势。

一个可扩展的机器学习优化框架用于连续决策