A descriptive study on public transport user behaviour from Live Bus Arrivals

In order to offer public transport that meet citizens’ needs for transport and further increase the use of bus services, Public Authorities need to analyse and understand travellers behaviour. Automatic Vehicle Location (AVL) data provide information on the observed time of arrival and departure of a bus at each stop. These data are fed into an algorithm to provide information to users on the expected time of arrival at the bus stop by an on-line service. In the city of London this service is called Live Bus Arrivals. This work describes the general behaviour of Live Bus Arrivals users by analysing the type of requests, localising them and compare them in different days of the week and time ranges. The objective is to identify some of the main passengers’ origin, destination and interchanges behaviour that could be of value to decision-makers and planners

A Vessel Pickup and Delivery Problem from the Disruption Management in Offshore Supply Vessel Operations

This paper considers a vessel pickup and delivery problem that arises in the case of disruptions in the supply vessel logistics in the offshore oil and gas industry. The problem can be modelled as a multi-vehicle pickup and delivery problem where delivery orders are transported by supply vessels from an onshore supply base (depot) to a set of offshore oil and gas installations, while pickup orders are to be transported from the installations back to the supply base (i.e. backload). We present both an arc-flow and a path-flow formulation for the problem. For the path-flow formulation we also propose an efficient dynamic programming algorithm for generating the paths, which represent feasible vessel voyages. It is shown through a computational study on various realistic test instances provided by a major oil and gas company that the path-flow model is superior with respect to computational performance.acceptedVersio

The OpenAIRE Research Community Dashboard: On Blending Scientific Workflows and Scientific Publishing

Despite the hype, the effective implementation of Open Science is hindered by several cultural and technical barriers. Researchers embraced digital science, use “digital laboratories” (e.g. research infrastructures, thematic services) to conduct their research and publish research data, but practices and tools are still far from achieving the expectations of transparency and reproducibility of Open Science. The places where science is performed and the places where science is published are still regarded as different realms. Publishing is still a post-experimental, tedious, manual process, too often limited to articles, in some contexts semantically linked to datasets, rarely to software, generally disregarding digital representations of experiments. In this work we present the OpenAIRE Research Community Dashboard (RCD), designed to overcome some of these barriers for a given research community, minimizing the technical efforts and without renouncing any of the community services or practices. The RCD flanks digital laboratories of research communities with scholarly communication tools for discovering and publishing interlinked scientific products such as literature, datasets, and software. The benefits of the RCD are show-cased by means of two real-case scenarios: the European Marine Science community and the European Plate Observing System (EPOS) research infrastructure. © Springer Nature Switzerland AG 2019

The number of partitions of a set and Superelliptic Diophantine equations

In this chapter we start by presenting some key results concerning the number of ordered k-partitions of multisets with equal sums. For these we give generating functions, recurrences and numerical examples. The coefficients arising from these formulae are then linked to certain elliptic and superelliptic Diophantine equations, which are investigated using some methods from Algebraic Geometry and Number Theory, as well as specialized software tools and algorithms. In this process we are able to solve some recent open problems concerning the number of solutions for certain Diophantine equations and to formulate new conjectures.N/

A note on posterior tight worst-case bounds for longest processing time schedules

© 2018, Springer-Verlag GmbH Germany, part of Springer Nature. This note proposes and analyzes a posterior tight worst-case bound for the longest processing time (LPT) heuristic for scheduling independent jobs on identical parallel machines with the objective of minimizing the makespan. It makes natural remarks on the well-known posterior worst-case bounds, and shows that the proposed bound can complement the well-known posterior bounds to synergistically achieve a better posterior worst-case bound for the LPT heuristic. Moreover, it gives some insight on LPT asymptotical optimality

Webs of Trust: Choosing Who to Trust on the Internet

none1How to decide whether to engage in transactions with strangers? Whether we’re offering a ride, renting a room or apartment, buying or selling items, or even lending money, we need a degree of trust that the others will behave as they should. Systems like Airbnb, Uber, Blablacar, eBay and others handle this by creating systems where people initially start as untrusted, and they gain reputation over time by behaving well. Unfortunately, these systems are proprietary and siloed, meaning that all information about transactions becomes property of the company managing the systems, and that there are two types of barriers to entry: first, whenever new users enter a new system they will need to restart from scratch as untrusted, without the possibility of exploiting the reputation they gained elsewhere; second, new applications have a similar cold-start problem: young systems, where nobody has reputation yet, are difficult to kickstart. We propose a solution based on a web of trust: a decentralized repository of data about past interactions between users, without any trusted third party. We think this approach can solve the aforementioned issue, establishing a notion of trust that can be used across applications while protecting user privacy. Several problems require consideration, such as scalability and robustness, as well as the trade-off between privacy and accountability. In this paper, we provide an overview of issues and solutions available in the literature, and we discuss the directions to take to pursue this project.mixedDell'Amico M.Dell'Amico, M