新的基于多目标优化的推荐算法

针对目前推荐系统效率问题,采用线上、线下分离策略,构建一种新的推荐系统框架.针对推荐系统多目标性和目前众多推荐算法适应性局限等特性,采用混合策略,提出一种新的多目标推荐算法.首先,对多个推荐算法进行加权混合;然后,构建以权重序列为自变量,推荐评价指标F调和率、多样性和新颖度为目标函数的多目标优化模型;其次,采用SPEA2多目标优化算法进行优化求解;最后,基于用户的购物偏好和Pareto解集向用户有针对性地进行购物推荐.实验结果表明:新的推荐算法较子推荐算法在F调和率上持平,在多样性上提高了1%,在新颖度上提高了11.5%;多目标的各个Pareto解在解空间中分布形成了密集邻近的点曲线.该推荐算法能够满足不同购物偏好用户的推荐要求.

New recommendation algorithm based on multi-objective optimization

In view of the efficiency problem of multi-objective recommender systems, this paper utilized the online and offline separation strategy to construct a new frame of recommender system. Aiming at the multi-objective feature of recommender system and current recommendation algorithms' limitations in adaptability, this paper put forward a new multi-objective recommendation algorithm based on the hybrid strategy. Firstly, the algorithm did weighted mix of multiple recommendation algorithms. Secondly, it established a multi-objective optimization model, using the weight sequence as variables and evaluation metrics including F-score, diversity and novelty as objective functions. Then, it optimized the solution through a second version of Strength Pareto Evolutionary Algorithm (SPEA2). Finally, it recommended items to users based on users' shopping preferences and the Pareto set. The experimental results show that: compared with the best single metric sub-recommendation algorithm, the new recommendation algorithm is nearly as well in the F-score, meanwhile increases by 1% in the diversity and increases by 11.5% in the novelty; the distribution of various Pareto solutions of multi-objective forms a dense and neighboring point curve in the solution space. So the recommender algorithm can satisfy the recommend requirements of users with different shopping preferences.