Embedding based product recommendations have gained popularity in recent years due to its ability to easily integrate to large-scale systems and allowing nearest neighbor searches in real-time. The bulk of studies in this area has predominantly been focused on similar item recommendations. Research on complementary item recommendations, on the other hand, still remains considerably under-explored. We define similar items as items that are interchangeable in terms of their utility and complementary items as items that serve different purposes, yet are compatible when used with one another. In this paper, we apply a novel approach to finding complementary items by leveraging dual embedding representations for products. We demonstrate that the notion of relatedness discovered in NLP for skip-gram negative sampling (SGNS) models translates effectively to the concept of complementarity when training item representations using co-purchase data. Since sparsity of purchase data is a major challenge in real-world scenarios, we further augment the model using synthetic samples to extend coverage. This allows the model to provide complementary recommendations for items that do not share co-purchase data by leveraging other abundantly available data modalities such as images, text, clicks etc. We establish the effectiveness of our approach in improving both coverage and quality of recommendations on real world data for a major online retail company. We further show the importance of task specific hyperparameter tuning in training SGNS. Our model is effective yet simple to implement, making it a great candidate for generating complementary item recommendations at any e-commerce website.

Recent advancements in deep neural networks for graph-structured data have led to state-of-the-art performance on recommender system benchmarks. However, making these methods practical and scalable to web-scale recommendation tasks with billions of items and hundreds of millions of users remains a challenge.Here we describe a large-scale deep recommendation engine that we developed and deployed at Pinterest. We develop a dataefficient Graph Convolutional Network (GCN) algorithm PinSage, which combines efficient random walks and graph convolutions to generate embeddings of nodes (i.e., items) that incorporate both graph structure as well as node feature information. Compared to prior GCN approaches, we develop a novel method based on highly efficient random walks to structure the convolutions and design a novel training strategy that relies on harder-and-harder training examples to improve robustness and convergence of the model.We deploy PinSage at Pinterest and train it on 7.5 billion examples on a graph with 3 billion nodes representing pins and boards, and 18 billion edges. According to offline metrics, user studies and A/B tests, PinSage generates higher-quality recommendations than comparable deep learning and graph-based alternatives. To our knowledge, this is the largest application of deep graph embeddings to date and paves the way for a new generation of web-scale recommender systems based on graph convolutional architectures.

A large number of empirical studies on applying self-attention models in the domain of recommender systems are based on offline evaluation and metrics computed on standardized datasets, without insights on how these models perform in real life scenarios. Moreover, many of them do not consider information such as item and customer metadata, although deep-learning recommenders live up to their full potential only when numerous features of heterogeneous types are included. Also, typically recommendation models are designed to serve well only a single use case, which increases modeling complexity and maintenance costs, and may lead to inconsistent customer experience. In this work, we present a reusable Attention-based Fashion Recommendation Algorithm (AFRA), that utilizes various interaction types with different fashion entities such as items (e.g., shirt), outfits and influencers, and their heterogeneous features. Moreover, we leverage temporal and contextual information to address both short and long-term customer preferences. We show its effectiveness on outfit recommendation use cases, in particular: 1) personalized ranked feed; 2) outfit recommendations by style; 3) similar item recommendation and 4) in-session recommendations inspired by most recent customer actions. We present both offline and online experimental results demonstrating substantial improvements in customer retention and engagement.

Humans inevitably develop a sense of the relationships between objects, some of which are based on their appearance. Some pairs of objects might be seen as being alternatives to each other (such as two pairs of jeans), while others may be seen as being complementary (such as a pair of jeans and a matching shirt). This information guides many of the choices that people make, from buying clothes to their interactions with each other. We seek here to model this human sense of the relationships between objects based on their appearance. Our approach is not based on fine-grained modeling of user annotations but rather on capturing the largest dataset possible and developing a scalable method for uncovering human notions of the visual relationships within. We cast this as a network inference problem defined on graphs of related images, and provide a large-scale dataset for the training and evaluation of the same. The system we develop is capable of recommending which clothes and accessories will go well together (and which will not), amongst a host of other applications.

推荐系统是机器学习系统的子类，它们采用复杂的信息过滤策略来减少搜索时间，并向任何特定用户建议最相关的项目。混合建议系统以不同的方式结合了多种建议策略，以从其互补的优势中受益。一些混合推荐系统已经结合了协作过滤和基于内容的方法来构建更强大的系统。在本文中，我们提出了一个混合推荐系统，该系统将基于最小二乘（ALS）的交替正方（ALS）的协作过滤与深度学习结合在一起，以增强建议性能，并克服与协作过滤方法相关的限制，尤其是关于其冷启动问题。本质上，我们使用ALS（协作过滤）的输出来影响深度神经网络（DNN）的建议，该建议结合了大数据处理框架中的特征，上下文，结构和顺序信息。我们已经进行了几项实验，以测试拟议混合体架构向潜在客户推荐智能手机的功效，并将其性能与其他开源推荐人进行比较。结果表明，所提出的系统的表现优于几个现有的混合推荐系统。

Complementary recommendation gains increasing attention in e-commerce since it expedites the process of finding frequently-bought-with products for users in their shopping journey. Therefore, learning the product representation that can reflect this complementary relationship plays a central role in modern recommender systems. In this work, we propose a logical reasoning network, LOGIREC, to effectively learn embeddings of products as well as various transformations (projection, intersection, negation) between them. LOGIREC is capable of capturing the asymmetric complementary relationship between products and seamlessly extending to high-order recommendations where more comprehensive and meaningful complementary relationship is learned for a query set of products. Finally, we further propose a hybrid network that is jointly optimized for learning a more generic product representation. We demonstrate the effectiveness of our LOGIREC on multiple public real-world datasets in terms of various ranking-based metrics under both low-order and high-order recommendation scenarios.

在这个大数据时代，当前一代很难从在线平台中包含的大量数据中找到正确的数据。在这种情况下，需要一个信息过滤系统，可以帮助他们找到所需的信息。近年来，出现了一个称为推荐系统的研究领域。推荐人变得重要，因为他们拥有许多现实生活应用。本文回顾了推荐系统在电子商务，电子商务，电子资源，电子政务，电子学习和电子生活中的不同技术和发展。通过分析有关该主题的最新工作，我们将能够详细概述当前的发展，并确定建议系统中的现有困难。最终结果为从业者和研究人员提供了对建议系统及其应用的必要指导和见解。

近年来，对机器学习算法在电子商务，全渠道营销和销售行业中的应用引起了人们的兴趣。它不仅符合算法的进步，而且还代表数据可用性，代表交易，用户和背景产品信息。以不同方式查找相关的产品，即替代品和补充对于供应商网站和供应商的建议至关重要，以执行有效的分类优化。本文介绍了一种新的方法，用于根据嵌入Cleora算法的图来查找产品的替代品和补充。我们还提供有关最先进的购物者算法的实验评估，研究了建议与行业专家的调查的相关性。结论是，此处提出的新方法提供了适当的推荐产品选择，需要最少的其他信息。该算法可用于各种企业，有效地识别替代品和互补产品选项。

目前的推荐方法帮助在线商家预测，每个访问用户，其现有产品的子集是最相关的。但是，除了有兴趣与现有产品匹配用户，商家也有兴趣了解他们的用户的潜在偏好。这确实可以帮助他们在未来产生或获得更好的匹配产品。我们认为现有推荐模型不能直接用于预测将使新产品能够更好地满足目标受众的需求的最佳功能组合。为了解决这个问题，我们转向生成模型，允许我们在文本和视觉空间中学习产品特征组合的明确分布。我们开发Warhhol，产品生成和推荐架构，以输入过去的用户购物活动，并产生新颖产品的相关文本和视觉描述。我们展示沃霍尔可以探讨最先进的推荐模型的性能，同时能够生成与给定用户配置文件相关的全新产品。

Self-attentive transformer models have recently been shown to solve the next item recommendation task very efficiently. The learned attention weights capture sequential dynamics in user behavior and generalize well. Motivated by the special structure of learned parameter space, we question if it is possible to mimic it with an alternative and more lightweight approach. We develop a new tensor factorization-based model that ingrains the structural knowledge about sequential data within the learning process. We demonstrate how certain properties of a self-attention network can be reproduced with our approach based on special Hankel matrix representation. The resulting model has a shallow linear architecture and compares competitively to its neural counterpart.

Session-Based Recommenders (SBRs) aim to predict users' next preferences regard to their previous interactions in sessions while there is no historical information about them. Modern SBRs utilize deep neural networks to map users' current interest(s) during an ongoing session to a latent space so that their next preference can be predicted. Although state-of-art SBR models achieve satisfactory results, most focus on studying the sequence of events inside sessions while ignoring temporal details of those events. In this paper, we examine the potential of session temporal information in enhancing the performance of SBRs, conceivably by reflecting the momentary interests of anonymous users or their mindset shifts during sessions. We propose the STAR framework, which utilizes the time intervals between events within sessions to construct more informative representations for items and sessions. Our mechanism revises session representation by embedding time intervals without employing discretization. Empirical results on Yoochoose and Diginetica datasets show that the suggested method outperforms the state-of-the-art baseline models in Recall and MRR criteria.

社交媒体营销在向广泛的受众群体推广品牌和产品价值方面起着至关重要的作用。为了提高其广告收入，诸如Facebook广告之类的全球媒体购买平台不断减少品牌有机帖子的覆盖范围，推动品牌在付费媒体广告上花费更多。为了有效地运行有机和付费社交媒体营销，有必要了解受众，调整内容以适合其兴趣和在线行为，这是不可能大规模手动进行的。同时，各种人格类型分类方案（例如Myers-Briggs人格类型指标）使得通过以统一和结构化的方式对受众行为进行分类，可以在更广泛的范围内揭示人格特质和用户内容偏好之间的依赖性。研究界尚待深入研究这个问题，而到目前为止，尚未广泛使用和全面评估，而不同人格特征对内容建议准确性的影响水平尚未得到广泛的利用和全面评估。具体而言，在这项工作中，我们通过应用一种新型人格驱动的多视图内容推荐系统，研究人格特征对内容推荐模型的影响，称为人格内容营销推荐引擎或Persic。我们的实验结果和现实世界案例研究不仅表明Persic执行有效的人格驱动的多视图内容建议，而且还允许采用可行的数字广告策略建议，当部署时能够提高数字广告效率超过420 ％与原始的人类指导方法相比。

Building a successful recommender system depends on understanding both the dimensions of people's preferences as well as their dynamics. In certain domains, such as fashion, modeling such preferences can be incredibly difficult, due to the need to simultaneously model the visual appearance of products as well as their evolution over time. The subtle semantics and non-linear dynamics of fashion evolution raise unique challenges especially considering the sparsity and large scale of the underlying datasets. In this paper we build novel models for the One-Class Collaborative Filtering setting, where our goal is to estimate users' fashion-aware personalized ranking functions based on their past feedback. To uncover the complex and evolving visual factors that people consider when evaluating products, our method combines high-level visual features extracted from a deep convolutional neural network, users' past feedback, as well as evolving trends within the community. Experimentally we evaluate our method on two large real-world datasets from Amazon.com, where we show it to outperform stateof-the-art personalized ranking measures, and also use it to visualize the high-level fashion trends across the 11-year span of our dataset.

With information systems becoming larger scale, recommendation systems are a topic of growing interest in machine learning research and industry. Even though progress on improving model design has been rapid in research, we argue that many advances fail to translate into practice because of two limiting assumptions. First, most approaches focus on a transductive learning setting which cannot handle unseen users or items and second, many existing methods are developed for static settings that cannot incorporate new data as it becomes available. We argue that these are largely impractical assumptions on real-world platforms where new user interactions happen in real time. In this survey paper, we formalize both concepts and contextualize recommender systems work from the last six years. We then discuss why and how future work should move towards inductive learning and incremental updates for recommendation model design and evaluation. In addition, we present best practices and fundamental open challenges for future research.

受到计算机愿景和语言理解的深度学习的巨大成功的影响，建议的研究已经转移到发明基于神经网络的新推荐模型。近年来，我们在开发神经推荐模型方面目睹了显着进展，这概括和超越了传统的推荐模型，由于神经网络的强烈代表性。在本调查论文中，我们从建议建模与准确性目标的角度进行了系统审查，旨在总结该领域，促进研究人员和从业者在推荐系统上工作的研究人员和从业者。具体而具体基于推荐建模期间的数据使用，我们将工作划分为协作过滤和信息丰富的建议：1）协作滤波，其利用用户项目交互数据的关键来源; 2）内容丰富的建议，其另外利用与用户和项目相关的侧面信息，如用户配置文件和项目知识图; 3）时间/顺序推荐，其考虑与交互相关的上下文信息，例如时间，位置和过去的交互。在为每种类型审查代表性工作后，我们终于讨论了这一领域的一些有希望的方向。

在本文中，我们提出了一种方法，用于预测社交媒体对等体之间的信任链接，其中一个是在多识别信任建模的人工智能面积。特别是，我们提出了一种数据驱动的多面信任信任建模，该信任建模包括许多不同的特征以进行全面分析。我们专注于展示类似用户的聚类如何实现关键新功能：支持更个性化的，从而为用户提供更准确的预测。在信任感知项目推荐任务中说明，我们在大yelp数据集的上下文中评估所提出的框架。然后，我们讨论如何提高社交媒体的可信关系的检测可以帮助在最近爆发的社交网络环境中支持在线用户的违法行为和谣言的传播。我们的结论是关于一个特别易受资助的用户基础，老年人的反思，以说明关于用户组的推理价值，期望通过通过数据分析获得的洞察力集成已知偏好的一些未来方向。

Natural Language Understanding has seen an increasing number of publications in the last few years, especially after robust word embeddings models became prominent, when they proved themselves able to capture and represent semantic relationships from massive amounts of data. Nevertheless, traditional models often fall short in intrinsic issues of linguistics, such as polysemy and homonymy. Any expert system that makes use of natural language in its core, can be affected by a weak semantic representation of text, resulting in inaccurate outcomes based on poor decisions. To mitigate such issues, we propose a novel approach called Most Suitable Sense Annotation (MSSA), that disambiguates and annotates each word by its specific sense, considering the semantic effects of its context. Our approach brings three main contributions to the semantic representation scenario: (i) an unsupervised technique that disambiguates and annotates words by their senses, (ii) a multi-sense embeddings model that can be extended to any traditional word embeddings algorithm, and (iii) a recurrent methodology that allows our models to be re-used and their representations refined. We test our approach on six different benchmarks for the word similarity task, showing that our approach can produce state-of-the-art results and outperforms several more complex state-of-the-art systems.

Code review is an integral part of any mature software development process, and identifying the best reviewer for a code change is a well accepted problem within the software engineering community. Selecting a reviewer who lacks expertise and understanding can slow development or result in more defects. To date, most reviewer recommendation systems rely primarily on historical file change and review information; those who changed or reviewed a file in the past are the best positioned to review in the future. We posit that while these approaches are able to identify and suggest qualified reviewers, they may be blind to reviewers who have the needed expertise and have simply never interacted with the changed files before. To address this, we present CORAL, a novel approach to reviewer recommendation that leverages a socio-technical graph built from the rich set of entities (developers, repositories, files, pull requests, work-items, etc.) and their relationships in modern source code management systems. We employ a graph convolutional neural network on this graph and train it on two and a half years of history on 332 repositories. We show that CORAL is able to model the manual history of reviewer selection remarkably well. Further, based on an extensive user study, we demonstrate that this approach identifies relevant and qualified reviewers who traditional reviewer recommenders miss, and that these developers desire to be included in the review process. Finally, we find that "classical" reviewer recommendation systems perform better on smaller (in terms of developers) software projects while CORAL excels on larger projects, suggesting that there is "no one model to rule them all."

推荐兴趣点是一个困难的问题，需要从基于位置的社交媒体平台中提取精确的位置信息。对于这种位置感知的推荐系统而言，另一个具有挑战性和关键的问题是根据用户的历史行为对用户的偏好进行建模。我们建议使用Transformers的双向编码器表示的位置感知建议系统，以便为用户提供基于位置的建议。提出的模型包含位置数据和用户偏好。与在序列中预测每个位置的下一项（位置）相比，我们的模型可以为用户提供更相关的结果。基准数据集上的广泛实验表明，我们的模型始终优于各种最新的顺序模型。

本次调查绘制了用于分析社交媒体数据的生成方法的研究状态的广泛的全景照片（Sota）。它填补了空白，因为现有的调查文章在其范围内或被约会。我们包括两个重要方面，目前正在挖掘和建模社交媒体的重要性：动态和网络。社会动态对于了解影响影响或疾病的传播，友谊的形成，友谊的形成等，另一方面，可以捕获各种复杂关系，提供额外的洞察力和识别否则将不会被注意的重要模式。