Activity path size for correlation between activity paths
In the activity path choice approach, the activity-episode sequence is modeled as a path in an activity network defining the activity type, duration and time of day. The IIA property might not be appropriate in the activity path approach since activity paths share unobserved attributes due to overlaps. Overlaps correspond to performing the same activity type at the same time and might be correlated. In this talk, we first show that the traditional Path Size correction term cancels out in the activity path approach and then propose two different deterministic corrections for correlation, the Primary Activity Path Size (PAPS) and the Activity Pattern Path Size (APPS), for the utility of overlapping activity paths.
ACCES Visualization Contest Awards & CoViz Open Day
(category : Pedestrians)
ACCES cordially invites you to the following two events this Friday, 29 May 2015:
Award Presentation for ACCES Visualization Contest and poster presentation session at 2 pm in the CO hall level 0 outside room CO 017.
The first ACCES Visualization Contest has attracted 55 entries from students and post-docs in diverse scientific and engineering areas.
A public display of all posters will be held from 29 May until 5 June. (Bring your smartphone to view directly the animations!)
Open Day for the ACCES CoViz facilityfrom 9 am to 6 pm in room MXC 320
Drop in during the day to view all the contest entries in full resolution, together with other demonstrations of the facility’s collaborative visualization capabilities. (Bring your own data to visualize!)
Danalet, A., and Bierlaire, M. (2015). Importance sampling for activity path choice. Proceedings of the Proceedings of the 15th Swiss Transport Research Conference (STRC) April 15-17, 2015.
Download: STRC / TRANSP-OR / Infoscience
We propose a model for the choice of an activity pattern. Models of activity participation patterns allow to assess the impact of demand management strategies on activity and destination choices.
In particular, we focus on choice set generation of activity patterns using recent developments in route choice modeling. Spatial choices deal with large choice sets. We develop a framework for choice set generation based on path choice. The activity-episode sequence is modeled as a path in an activity network defining the activity type, duration and time of day. The large dimensionality of the choice set is managed through an importance sampling based on Metropolis-Hastings algorithm.
Our model can be used to forecast demand at the urban scale and also in pedestrian facilities, such as transport hubs or mass gathering. Validation of the approach is performed on synthetic data and a case study using WiFi traces on a campus is presented.
Tinguely, L., Danalet, A., de Lapparent, M., and Bierlaire, M. (2015). Destination Choice Model including a panel effect using WiFi localization in a pedestrian facility. Proceedings of the Proceedings of the 15th Swiss Transport Research Conference (STRC) April 15-17, 2015.
Download: STRC / TRANSP-OR / Infoscience
This paper proposes a general methodology to model pedestrian destination choice from WiFi localization in multi-modal transport facilities (e.g., airports, railway stations). It is based on the output of Danalet et al.(2014) method to generate candidates of activity episode sequences from WiFi measurements, locations of activities on a map and prior information.
Destination choice is nested to the activity choice. An individual first chooses an activity
(Danalet and Bierlaire, 2015), and then selects the destination where to perform it. We propose an approach to model destination choice accounting for panel nature of data. We compare static, dynamic strictly exogenous and dynamic with two different agent effect corrections models with inspiration from Wooldridge (2002) method.
In a case study using WiFi traces on EPFL campus, we focus on one activity: catering. The
choice set contains 21 alternatives on campus (restaurants, self-services, cafeterias, ...). Our models reveal that the choice of a catering facility especially depends on habits (e.g., where an individual ate the previous time), distance to walk from the previous activity episode (calculated with a weighted shortest path algorithm) and destination specific determinants. Price has a non-significant impact in this case study, most likely because the price range on campus is narrow. The models are successfully validated using the same WiFi dataset.
EPFL pedestrian semantically-enriched graph (SERG) with points of interest and pedestrian network, as defined and use in:
A. Danalet, B. Farooq and M. Bierlaire. A Bayesian Approach to Detect Pedestrian Destination-Sequences from WiFi Signatures, in Transportation Research Part C: Emerging Technologies, vol. 44, p. 146 - 170, 2014. DOI: 10.1016/j.trc.2014.03.015
Basically, this system is planned for pedestrian facilities. Since I post a lot of things about EPFL campus and pedestrian behavior on this blog, I think this high level analysis might be of interest :)
On slide 18 of the first presentation, we can observe that selling tap beer significantly impacts the choice of a restaurant on EPFL campus (t-test>3).
More seriously, these two presentations give decision-aid tools for the modeling of activity and destination choices in pedestrian facilities. Case studies are presented on real WiFi traces. For the activity choice, we focus on the choice set generation. For destination choice, we focus on the effect of the previous choice on the current choice (panel effect).
The proceedings of the conference will be available by end of May.
SeminApero - Call for Presentations and Save the Date - June 10, 2015
(category : SeminApero)
An event by PhD students in Civil and Environmental Engineering
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YOU are invited to join your colleagues from the civil and environmental engineering doctoral program for a networking event. The goal is to bring together doctoral students to build and strengthen relations within EDCE (Doctoral program in Civil & Environmental Engineering), and with students from the Architecture & Sciences of the City (EDAR) program. Post-docs are also welcome!
The 8th edition of the seminApero will be held on Wednesday, 10 June at 17h00.
We are looking for students from both doctoral programs to present their work in a 5-minute, 5-slide presentation (volunteer by sending an email to Parag). This casual seminar will last less than an hour (6x5') and will be followed by an apero where you can meet and socialise with your fellow doctoral students in a relaxed atmosphere.
For registration or further questions you can write to Parag or check out our blog.
TU es invité(e) à rejoindre tes collègues doctorant-e-s du programme de génie civil et environnemental pour un évènement de réseautage. Le but est de rapprocher les doctorant-e-s de l'EDCE (Ecole Doctorale Génie Civil et Environnement) afin d’établir et de renforcer les liens entre nous, et avec les doctorant-e-s de l’EDAR (Ecole Doctorale Architecture & Sciences de la ville). Les post-docs sont également invitée !
La 8e édition du seminApero se tiendra le mercredi 10 juin à 17h00.
Nous sommes à la recherche d’étudiant-e-s des deux écoles doctorales voulant présenter leur travail dans un exposé de 5 minutes, 5 diapositives (si vous êtes intéressé-e, envoyez un email à Parag). Il s’agit d’un séminaire à caractère informel de moins d'une heure (6x5'). Celui-ci sera suivi d’un apéro laissant place aux rencontres et discussions dans une ambiance détendue.
Pour présenter ou pour toute autre information, contacte Parag par email ou consulte notre blog.