As multimedia content continues to grow on the web, the integration of visual and textual data has become a crucial challenge for web applications, particularly in recommendation systems. Large Vision Language Models (LVLMs) have demonstrated considerable potential in addressing this challenge across various tasks that require such multimodal integration. However, their application in multimodal sequential recommendation (MSR) has not been extensively studied. To bridge this gap, we introduce MSRBench, the first comprehensive benchmark designed to systematically evaluate different LVLM integration strategies in web-based recommendation scenarios. We benchmark three state-of-the-art LVLMs, i.e., GPT-4 Vision, GPT-4o, and Claude-3-Opus, on the next item prediction task using the constructed Amazon Review Plus dataset, which includes additional item descriptions generated by LVLMs. Our evaluation examines five integration strategies: using LVLMs as recommender, item enhancer, reranker, and various combinations of these roles. The benchmark results reveal that 1) using LVLMs as rerankers is the most effective strategy, significantly outperforming others that rely on LVLMs to directly generate recommendations or only enhance items; 2) GPT-4o consistently achieves the best performance across most scenarios, particularly when employed as a reranker; 3) the computational inefficiency of LVLMs presents a major barrier to their widespread adoption in real-time multimodal recommendation systems. Our code and datasets are available at https://github.com/PALIN2018/MSRBench.

Traffic speed prediction is an important part of intelligent transportation systems (ITS). If road traffic speed is predicted accurately, we can provide not only evidence for urban traffic managers, but also support for other road services such as path planning. Traditional prediction models usually ignore the spatio-temporal dependencies of the traffic dynamics and influences of external factors. This paper proposes a Temporal Graph Convolutional Networks (GTCN) which is composed of spatio-temporal component and external component to solving the traffic speed prediction problem. The spatio-temporal component integrates k-order spectral graph convolution and dilated casual convolution to capture the spatio-temporal dependencies. The external component takes social factors such as day of the week into account. To further improve the prediction accuracy, we consider the road structure features and point of interest (POI) during the construction of the sensor station graph. We evaluate the prediction model on two datasets from the Caltrans Performance Measurement System (CalTrans PeMS). Experiments show that the proposed GTCN model obtains high accuracy and outperforms state-of-the-art baselines.

Along with the proliferation of online digital map and location-based service, very large POI (point of interest) databases have been constructed where a record corresponds to a POI with information including name, category, address, geographical location and other features. A basic spatial query in POI database is POI retrieval. In many scenarios, a user cannot provide enough information to pinpoint the POI except some clue. For example, a user wants to identify a caf é in a city visited many years ago. SHe cannot remember the name and address but she still recalls that "the caf é is about 200 meters away from a restaurant; and turning left at the restaurant there is a bakery 500 meters away, etc.". Intuitively, the clue, even partial and approximate, describes the spatio-textual context around the targeted POI. Motivated by this observation, this work investigates clue-based spatio-textual query which allows user providing clue, i.e., some nearby POIs and the spatial relationships between them, in POI retrieval. The objective is to retrieve k POIs from a POI database with the highest spatio-textual context similarities against the clue. This work has deliberately designed data-quality-tolerant spatio-textual context similarity metric to cope with various data quality problems in both the clue and the POI database. Through crossing valuation, the query accuracy is further enhanced by ensemble method. Also, this work has developed an index called roll-out-star R-tree (RSR-tree) to dramatically improve the query processing efficiency. The extensive tests on data sets from the real world have verified the superiority of our methods in all aspects.

This paper proposes and solves a novel type of spatial queries named Subject-oriented Top-k hot Region (STR) queries. Given a subject S defined by a feature set R and features importance denoted by weights, an STR query retrieves k non-overlapping regions that have the highest scores computed by the number of feature objects and their weights. As an example, the culture subject is defined by exhibition halls, libraries and museums. On the subject, an STR query finds cultural centers intensively distributed feature objects. In this paper, we propose two efficient algorithms, single-partition (SP) algorithm and dual-partition (DP) algorithm, to process STR queries. Extensive experiments evaluate the proposed solutions under a wide range of parameter settings.

Continuously identifying pre-defined patterns in a streaming time series has strong demand in various applications. While most existing works assume the patterns are in equal length and tolerance, this work focuses on the problem where the patterns have various lengths and tolerances, a common situation in the real world. The challenge of this problem roots on the strict space and time requirements of processing the arriving and expiring data in high-speed stream, combined with difficulty of coping with a large number of patterns with various lengths and tolerances. We introduce a novel concept of converging envelope which bounds the tolerance of a group of patterns in various tolerances and equal length and thus dramatically reduces the number of patterns for similarity computation. The basic idea of converging envelope has potential to more general index problems. To index patterns in various lengths and tolerances, we partition patterns into sub-patterns in equal length and an multi-tree index is developed in this paper.