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Causal Discovery and Inference towards Urban Elements and Associated Factors

Feng, Tao, Zhang, Yunke, Fan, Xiaochen, Wang, Huandong, Li, Yong

arXiv.org Artificial Intelligence

To uncover the city's fundamental functioning mechanisms, it is important to acquire a deep understanding of complicated relationships among citizens, location, and mobility behaviors. Previous research studies have applied direct correlation analysis to investigate such relationships. Nevertheless, due to the ubiquitous confounding effects, empirical correlation analysis may not accurately reflect underlying causal relationships among basic urban elements. In this paper, we propose a novel urban causal computing framework to comprehensively explore causalities and confounding effects among a variety of factors across different types of urban elements. In particular, we design a reinforcement learning algorithm to discover the potential causal graph, which depicts the causal relations between urban factors. The causal graph further serves as the guidance for estimating causal effects between pair-wise urban factors by propensity score matching. After removing the confounding effects from correlations, we leverage significance levels of causal effects in downstream urban mobility prediction tasks. Experimental studies on open-source urban datasets show that the discovered causal graph demonstrates a hierarchical structure, where citizens affect locations, and they both cause changes in urban mobility behaviors. Experimental results in urban mobility prediction tasks further show that the proposed method can effectively reduce confounding effects and enhance performance of urban computing tasks.


TiVaT: Joint-Axis Attention for Time Series Forecasting with Lead-Lag Dynamics

Ha, Junwoo, Kwon, Hyukjae, Kim, Sungsoo, Lee, Kisu, Kim, Ha Young

arXiv.org Artificial Intelligence

Multivariate time series (MTS) forecasting plays a crucial role in various realworld applications, yet simultaneously capturing both temporal and inter-variable dependencies remains a challenge. Conventional Channel-Dependent (CD) models handle these dependencies separately, limiting their ability to model complex interactions such as lead-lag dynamics. To address these limitations, we propose TiVaT (Time-Variable Transformer), a novel architecture that integrates temporal and variate dependencies through its Joint-Axis (JA) attention mechanism. Ti-VaT's ability to capture intricate variate-temporal dependencies, including asynchronous interactions, is further enhanced by the incorporation of Distance-aware Time-Variable (DTV) Sampling, which reduces noise and improves accuracy through a learned 2D map that focuses on key interactions. Notably, it excels in capturing complex patterns within multivariate time series, enabling it to surpass or remain competitive with state-of-the-art methods. This positions TiVaT as a new benchmark in MTS forecasting, particularly in handling datasets characterized by intricate and challenging dependencies. However, handling both temporal and inter-variable dependencies in MTS remains a challenge. MTS models are typically classified as either Channel-Independent (CI) or Channel-Dependent (CD) based on how they handle inter-variable relationships. CI models process variables independently, which makes them resilient to noise and overfitting but neglects crucial inter-variable dependencies required for complex datasets. Recent CD models, such as iTransformer (Liu et al., 2023) and CARD (Wang et al., 2024b), use Transformer architectures to model these dependencies, improving predictive accuracy.


Consecutive Support: Better Be Close!

de Graaf, Edgar, de Graaf, Jeannette, Kosters, Walter A.

arXiv.org Artificial Intelligence

We propose a new measure of support (the number of occur- rences of a pattern), in which instances are more important if they occur with a certain frequency and close after each other in the stream of trans- actions. We will explain this new consecutive support and discuss how patterns can be found faster by pruning the search space, for instance using so-called parent support recalculation. Both consecutiveness and the notion of hypercliques are incorporated into the Eclat algorithm. Synthetic examples show how interesting phenomena can now be discov- ered in the datasets. The new measure can be applied in many areas, ranging from bio-informatics to trade, supermarkets, and even law en- forcement. E.g., in bio-informatics it is important to find patterns con- tained in many individuals, where patterns close together in one chro- mosome are more significant.



Spreading Activation over Distributed Microfeatures

Hendler, James

Neural Information Processing Systems

One att·empt at explaining human inferencing is that of spreading activat,ion, particularly in the st.ructured connectionist paradigm. This has resulted in t.he building of systems with semantically nameable nodes which perform inferencing by examining t.he pat,t.erns of activation spread.


Spreading Activation over Distributed Microfeatures

Hendler, James

Neural Information Processing Systems

One att·empt at explaining human inferencing is that of spreading activat,ion, particularly in the st.ructured connectionist paradigm. This has resulted in t.he building of systems with semantically nameable nodes which perform inferencing by examining t.he pat,t.erns of activation spread.