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Reviews: Explicit Planning for Efficient Exploration in Reinforcement Learning

Neural Information Processing Systems

This paper introduces the interesting idea of demand matrices to more efficiently do pure exploration. Demand matrices simply specific the minimum number of times needed to visit every state-action pair. This is then treated as an additional part of the state in an augmented MDP, which can then be solved to derive the optimal exploration strategy to achieve the specified initial demand. While the idea is interesting and solid, there are downsides to the idea itself and some of the analysis in this paper that could be improved upon. There are no theoretical guarantees that using this algorithm with a learned model at the same time will work.


Origin-Destination Demand Prediction: An Urban Radiation and Attraction Perspective

Ma, Xuan, Bao, Zepeng, Zhong, Ming, Zhu, Yuanyuan, Li, Chenliang, Jiang, Jiawei, Li, Qing, Qian, Tieyun

arXiv.org Artificial Intelligence

--In recent years, origin-destination (OD) demand prediction has gained significant attention for its profound implications in urban development. Existing deep learning methods primarily focus on the spatial or temporal dependency between regions yet neglecting regions' fundamental functional difference. Though physical methods have characterised regions' functions by their radiation and attraction capacities, these functions are defined on numerical factors like population without considering regions' intrinsic nominal attributes, e.g., a region is a residential or industrial district. Moreover, the complicated relationships between two types of capacities, e.g., the radiation capacity of a residential district in the morning will be transformed into the attraction capacity in the evening, are totally missing from physical methods. In this paper, we not only generalize the physical radiation and attraction capacities into the deep learning framework with the extended capability to fulfil regions' functions, but also present a new model that captures the relationships between two types of capacities. Specifically, we first model regions' radiation and attraction capacities using a bilateral branch network, each equipped with regions' attribute representations. We then describe the transformation relationship of different capacities within the same region using a parameter generation method. We finally unveil the competition relationship of different regions with the same attraction capacity through adversarial learning. Extensive experiments on two city datasets demonstrate the consistent improvements of our method over the state-of-the-art baselines, as well as the good explainability of regions' functions using their nominal attributes. With the spread of ride-hailing platforms like Uber and Didi, intelligent transportation systems have emerged as a vibrant research domain [1]-[3]. These systems are designed to offer convenient ride services, improve public transportation efficiency through proactive order assignment, and optimize profitability by identifying high-profit routes based on historical passenger demands [4]. Among the wide spectrum of applications, traffic demand forecasting is the focal point due to its vital role in urban development, traffic control, and route planning [5]-[11]. The conventional task in this field involves the prediction of the potential number of passenger demands in a specific region [10], [12], [13]. However, such a task is unable to capture associations in inter-regional flows. Tieyun Qian is the corresponding author. Figure 1: (a) An illustration of the region partition in Manhattan, New Y ork, and (b) and (c) are visualizations of the taxi outflow and inflow demand in a designated region with a red mark in (a) on 2019-01-17, respectively.


Graph Neural Modeling of Network Flows

Darvariu, Victor-Alexandru, Hailes, Stephen, Musolesi, Mirco

arXiv.org Artificial Intelligence

Network flow problems, which involve distributing traffic over a network such that the underlying infrastructure is used effectively, are ubiquitous in transportation and logistics. Among them, the Multi-Commodity Network Flow (MCNF) problem is of general interest, as it concerns the distribution of multiple flows of different sizes between several sources and sinks, while achieving effective utilization of the links. Due to the appeal of data-driven optimization, these problems have increasingly been approached using graph learning methods. In this paper, we propose a novel graph learning architecture for network flow problems called Per-Edge Weights (PEW). This method builds on a Graph Attention Network and uses distinctly parametrized message functions along each link. We extensively evaluate the proposed solution through an Internet flow routing case study using $17$ Service Provider topologies and $2$ routing schemes. We show that PEW yields substantial gains over architectures whose global message function constrains the routing unnecessarily. We also find that an MLP is competitive with other standard architectures. Furthermore, we shed some light on the relationship between graph structure and predictive performance for data-driven routing of flows, an aspect that has not been considered by existing work in the area.


A Deep Learning Perspective on Network Routing

Perry, Yarin, Frujeri, Felipe Vieira, Hoch, Chaim, Kandula, Srikanth, Menache, Ishai, Schapira, Michael, Tamar, Aviv

arXiv.org Artificial Intelligence

Routing is, arguably, the most fundamental task in computer networking, and the most extensively studied one. A key challenge for routing in real-world environments is the need to contend with uncertainty about future traffic demands. We present a new approach to routing under demand uncertainty: tackling this challenge as stochastic optimization, and employing deep learning to learn complex patterns in traffic demands. We show that our method provably converges to the global optimum in well-studied theoretical models of multicommodity flow. We exemplify the practical usefulness of our approach by zooming in on the real-world challenge of traffic engineering (TE) on wide-area networks (WANs). Our extensive empirical evaluation on real-world traffic and network topologies establishes that our approach's TE quality almost matches that of an (infeasible) omniscient oracle, outperforming previously proposed approaches, and also substantially lowers runtimes.


STDI-Net: Spatial-Temporal Network with Dynamic Interval Mapping for Bike Sharing Demand Prediction

Pian, Weiguo, Wu, Yingbo, Kou, Ziyi

arXiv.org Artificial Intelligence

As an economical and healthy mode of shared transportation, Bike Sharing System (BSS) develops quickly in many big cities. An accurate prediction method can help BSS schedule resources in advance to meet the demands of users, and definitely improve operating efficiencies of it. However, most of the existing methods for similar tasks just utilize spatial or temporal information independently. Though there are some methods consider both, they only focus on demand prediction in a single location or between location pairs. In this paper, we propose a novel deep learning method called Spatial-Temporal Dynamic Interval Network (STDI-Net). The method predicts the number of renting and returning orders of multiple connected stations in the near future by modeling joint spatial-temporal information. Furthermore, we embed an additional module that generates dynamical learnable mappings for different time intervals, to include the factor that different time intervals have a strong influence on demand prediction in BSS. Extensive experiments are conducted on the NYC Bike dataset, the results demonstrate the superiority of our method over existing methods.