Towards Robust Deep Reinforcement Learning for Traffic Signal Control: Demand Surges, Incidents and Sensor Failures

Reinforcement learning (RL) constitutes a promising solution for alleviating the problem of traffic congestion. In particular, deep RL algorithms have been shown to produce adaptive traffic signal controllers that outperform conventional systems. However, in order to be reliable in highly dynamic urban areas, such controllers need to be robust with the respect to a series of exogenous sources of uncertainty. In this paper, we develop an open-source callback-based framework for promoting the flexible evaluation of different deep RL configurations under a traffic simulation environment. With this framework, we investigate how deep RL-based adaptive traffic controllers perform under different scenarios, namely under demand surges caused by special events, capacity reductions from incidents and sensor failures. We extract several key insights for the development of robust deep RL algorithms for traffic control and propose concrete designs to mitigate the impact of the considered exogenous uncertainties.Comment: 8 page

The Applicability of the Principles of Activity-Based Costing System in a Higher Education Institution

In view of the growing relevance of management accounting in the administration of universities, the recognition of the need for an effective costs assessment system (Jarrar, Smith and Dolley, 2007), and the profound changes that have been occurring in the structure of Portuguese universities, developing and implementing models that may actually be useful for the management of these institutions will be of major importance. The aim of this work is to present a costs assessment model, influenced by the activity-based costing (ABC) and applicable to higher education institutions. Therefore, based on the procedures used by the services of a faculty belonging to a large Portuguese university, we tried to create a model which allows the attribution of each department’s expenditure to the various cost objects – courses, research projects, services. In this way, we tried to present a model which, without being too complex, has a level of detail sufficient enough to enable the production of reliable information and which can be applied in the context of higher education institutions.Activity-based costing, Management accounting

Hybrid photonic entanglement: Realization, characterization and applications

We show that the quantum disentanglement eraser implemented on a two-photon system from parametric down-conversion is a general method to create hybrid photonic entanglement, namely the entanglement between different degrees of freedom of the photon pair. To demonstrate this, we generate and characterize a source with tunable degree of hybrid entanglement between two qubits, one encoded in the transverse momentum and position of a photon, and the other in the polarization of its partner. In addition, we show that a simple extension of our setup enables the generation of two-photon qubit-qudit hybrid entangled states. Finally, we discuss the advantages that this type of entanglement can bring for an optical quantum network.Comment: Published versio