QLS SEMINAR - Thursday 15 October

[Quantitative Life Sciences]

QUANTITATIVE LIFE SCIENCES SEMINAR

Thursday, 15 October - 16:00
Central area, 2nd floor, ex-SISSA building

Guest speaker: Rytis Paskauskas
Information Science and Technologies (ISTI) institute “A. Faedo”
                           of the Italian National Research Council 
(CNR), Pisa, Italy

"Model-based Assessment of Aspects of User-satisfaction in Bicycle 
Sharing Systems"*
*
Abstract:

Modelling of bike sharing systems as Markov Renewal Process is examined 
with the aim of capturing and assessing various forms of user 
(dis)satisfaction. A class of models with minimal assumptions about 
distributions of bicycle parking stations and service requests is 
developed in which rational commuter behaviour is taken into account. 
Stochastic time evolution of these models is studied, using a 
generalised version of Gillespie's exact stochastic integration 
algorithm that accounts for non-Markovian inter-event times. The model 
is shown to reproduce quite faithfully the trip-duration statistics of 
smaller and larger real bike sharing systems, such as those in London 
and Pisa, including the algebraic `tails' of these distributions that 
are made up of longer cycling trips. The latter are related to user's 
difficulties to find suitable parking places therefore to a potential 
source of distress. The model also predicts other salient features such 
as a mode at 10 minutes and crossover behaviour at about 30 minutes. The 
framework can be extended to include measures either designed to 
improve, or anyway to affect, the user experience with a system, such as 
incentives for spontaneous vehicle redistribution. User satisfaction is 
difficult to assess in real systems because these naturally collect only 
data about trips that actually, and thus successfully, took place giving 
only partial and biased insight in user satisfaction.


-- 
Erica Sarnataro
Group Secretary
Quantitative Life Sciences
The Abdus Salam International Centre for Theoretical Physics (ICTP)
Trieste,  Italy
Tel. +39-040-2240623
e-mail: qls at ictp.it