Thomas Leduc

Thomas Leduc
French National Centre for Scientific Research | CNRS · Institut des Sciences humaines et sociales (INSHS)

PhD in Computer Science

About

103
Publications
25,008
Reads
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411
Citations
Citations since 2016
22 Research Items
236 Citations
201620172018201920202021202201020304050
201620172018201920202021202201020304050
201620172018201920202021202201020304050
201620172018201920202021202201020304050
Additional affiliations
January 2003 - August 2020
French National Centre for Scientific Research
Position
  • IRHC
January 2003 - August 2020
École Nationale Supérieure d'Architecture Nantes
Position
  • IRHC
Education
July 1999
Sorbonne Université
Field of study
  • Computer Science
September 1992 - July 1994
Institut National des Sciences Appliquées de Rouen
Field of study
  • Applied mathematics and computational engineering

Publications

Publications (103)
Article
Full-text available
According to the permeability theory, the spatial configuration, and more precisely, the presence of occlusions in our surroundings may invite us to explore our environment. This article aims to analyze, in a systematic and reproducible way, the predictability of our visual environment. To assess this property for every observing point, we remind t...
Article
Full-text available
The understanding of pedestrian mobility behaviors often relies on aggregated analyses. These analyses correlate spatial entities with the mobility streams that cross them. These types of approach are in particular developed to assess the impact of built morphology on pedestrian behavior. To go a bit further, we propose an unaggregated analysis, ba...
Data
Full-text available
The aim of this paper is to couple the isovists field (a useful tool to determine the surroundings) with a classical digital signal processing method so as to classify the open spaces all along a pedestrian pathway and identify some urban patterns. Indeed, it could be of a great interest to determine automatically the type of surrounding spaces to...
Chapter
Full-text available
The aim of this paper is to evaluate the impact of visual ambiences (visualscape) onto an urban pedestrian pathway. This work takes place within the interdisciplinary research project called Ambioflux, dealing with the sustainable mobility issues in the city. We add to the spatial semantic layer GDMS (Generic Datasource Management System) an innova...
Book
Full-text available
Considering sustainable development of cities implies investigating cities in a holistic way taking into account many interrelations between various urban or environmental issues. 3D city models are increasingly used in different cities and countries for an intended wide range of applications beyond mere visualization. Could these 3D City models be...
Article
The city is a complex “object” whose structure can be studied at several levels of scale. In this article, we propose to work on the scale of the street, the one in which the pedestrian is immersed, and more precisely on the scale of its articulations, the street intersections. These are indeed structuring places, variously walkable, potentially di...
Article
Full-text available
360° imagery has been increasingly used to estimate the subjective qualities of the urban space, such as the feeling of safety or the liveliness of a place. These spherical panoramas offer an immersive view of the urban scene, close to the experience of a pedestrian. In recent years, Deep Learning approaches have been developed for this estimation...
Article
Urban designers face the challenge of preserving urban life by creating public spaces that are resilient to rising temperatures. This paper studies the dissemination of urban designs specific to summer (‘urban coolspots’) throughout urban design media. First, the study of an inventory of urban coolspots (182 references) delineates their urban conte...
Article
Full-text available
In the context of global warming, cities promote temporary or permanent public space designs based on the integration of various cooling techniques, hereafter called spatio-climatic devices, to locally cool down the atmosphere and preserve urban liveability. Such public spaces create interaction opportunities for citizens to seek thermal pleasure o...
Article
This study presents an one-way coupling approach between the ENVI-met microclimate model and the EnergyPlus building energy simulation program, to assess the effect of the urban greenery on the improvement of the buildings' cooling energy needs, in a dense urban area in Thessaloniki, Greece. Three commonly encountered urban tree species with differ...
Article
In geographic information science and technology, various methods and studies exist to characterize the linearity, rectangularity, convexity, circularity or compactness, sinuosity or tortuosity of a given spatial shape. Although there is much work on ellipticity in image processing, we do not address, in geomatics, the issue of matching to a refere...
Article
Full-text available
The contemporary design of public spaces integrates frequently urban cooling installations for thermal comfort in summertime. However, the details of the thermal experience that they provide is yet partially unknown. This paper studies how methods and techniques arising from microclimatology, urban studies and sensory studies can interact for chara...
Conference Paper
Full-text available
The graphical representation of a complex polygonal object, such as an isovist field (i.e. a 2D isovist in its evolution over time along a pedestrian path in an urban environment) is a hard research issue that was stated in the late 1970s by Benedikt [1]. The generalized space-time cube from Bach and al. [2] is a conceptual framework allowing to pr...
Article
This article is a formalisation of the local climate zone (LCZ) classification on a local and micro scales. It is also an attempt to transpose this classification to a fine grained level of detail. The urban space is divided into virtual sensors for which five morphological indicators are calculated. Therefore, this work exposes a comparison of two...
Article
This research focuses on the automatic classification of small urban fragments through a morphological analysis of cognitivist inspiration. The recognition algorithm is performed on observer-centric forms, constructed through the use of visibility assessment techniques over a series of individual points of view. These tools are (1) the isovist for...
Article
Full-text available
Nous présentons dans cet article un essai de quantification de l'impression de confinement d’un piéton immergé dans la ville. Cette quantification repose sur un ensemble de qualités perceptuelles évoquées par (Ewing et al., 2006) ou (Dupagne et al., 1999) telles la mesure de l’« enfermement urbain », la « cohérence formelle », la « profondeur urbai...
Article
Full-text available
A full coupling between a CFD code, a thermo-radiative model and a building energy simulation model enables Solene-microclimat software to calculate both building thermal behavior and urban microclimate with the retroaction of buildings on microclimate. However, this full coupling is time consuming and it is legitimate to wonder if it is always nec...
Chapter
The spatio-cognitive properties of urban surroundings must be taken into account in the design of urban spaces. However, there are few methods and software tools to assess the visual properties and the spatial identity of places, and most of them are based on two-dimensional visibility analysis only and on a static analysis of surroundings. Our pro...
Conference Paper
Full-text available
A full coupling between a CFD code, a thermo-radiative model and a building energy simulation model enables Solene-microclimat software to calculate both building thermal behavior and urban microclimate with the retroaction of buildings on microclimate. However, this full coupling is time consuming and it is legitimate to wonder if it is always nec...
Conference Paper
The dual experience of the city provided by our connected devices can be used to create an alternative representation of the city. This paper presents a method to automatically translate the physical parameters, from a morphological analysis of the space surrounding the user along a path, into a textual description. As these physical parameters are...
Conference Paper
Full-text available
Nowadays, urban virtual models are important supports for conducting quantitative and qualitative analyses. However, by working at the district scale, it is not always clear which is the influence of the various components that contribute to shape the urban environment and that are relevant for obtaining reliable urban analyses. Within this context...
Conference Paper
Full-text available
In this article, we propose a renewed site-centric solution that allows us to characterize a specific region of interest by defining the extent of the surroundings that influence sunlight exposure. The proposed method is a mix of an adaptive refinement and a visual-based clipping technique. This method has been implemented in the SketchUp context a...
Presentation
Full-text available
Quality and quantity of visual perception: recent ICT improvements for tridimensional visibility analysis -
Technical Report
Full-text available
Ce rapport technique vise à rendre compte des premiers tests de la donnée à composante spatiale (socle 3D, couverture partielle du secteur centre-ville) transmise par Nantes Métropole et la ville de Nantes au CRENAU - UMR AAU en mars 2015.
Article
Full-text available
Several studies intended to explore the correlation between urban planning and health have sought to assess the impact of this planning or of physically perceptible environmental conditions in terms of the stress of individuals placed in these situations. The method we propose is related to moods or atmospheres to the extent that it combines a situ...
Conference Paper
La genèse de nos travaux, le projet Ambioflux avait pour objectif d'étudier le ressenti des ambiances urbaines en situation de mobilité douce (déplacement piéton). Dans le cadre de ce projet, nous avons constaté que, pour un promeneur en situation de dérive (au sens de la théorie éponyme des situationnistes), certains indicateurs de morphométrie du...
Article
Full-text available
The estimation of the seismic vulnerability of buildings at an urban scale, a crucial element in any risk assessment, is an expensive, time-consuming, and complicated task, especially in moderate-to-low seismic hazard regions, where the mobilization of resources for the seismic evaluation is reduced, even if the hazard is not negligible. In this pa...
Conference Paper
Full-text available
Dans le cadre de la mobilité pédestre, on connaît peu l'incidence des espaces dits ouverts sur les pratiques pédestres à une échelle très fine. Or, nous postulons qu'ils sont importants dans le registre de la mobilité piétonne car ils conditionnent en partie l'environnement de déplacement, les ambiances urbaines auxquelles sont confrontés les piéto...
Conference Paper
Full-text available
According to permeability theory, surroundings' configuration and, more precisely, the existence of occlusions in our enclosure may invite us to explore our environment. This article aims to analyze, in a systematic and reproducible way, the ratio of mystery in one's surrounding visualscape. To assess this property in each place, we recall three in...
Data
Full-text available
The aim of this paper is to evaluate the impact of visual ambiences (visualscape) onto an urban pedestrian pathway. This work takes place within the interdisciplinary research project called Ambioflux, dealing with the sustainable mobility issues in the city. We add to the spatial semantic layer GDMS (Generic Datasource Management System) an innova...
Conference Paper
Full-text available
Density is probably one of the most used indicators to characterize urban development. Even if it is a quantitative and properly defined measure, there are still problems to use it properly. This paper proposes a renewed approach to characterize urban density based on buildings' footprints. It can be applied on huge datasets and allows multi-level...
Chapter
Full-text available
The series of studies that are focused on the Old Bazaar - the historic and protected district in city of Skopje, exercise the complex spatial analysis or the urban environment with use of models of visibility, patterns of spatial configuration and pedestrian behavior as scientific knowledge and research tools for better understanding of the proces...
Chapter
Full-text available
In the present joint research, authors are trying to correlate surroundings assessments with pedestrian movement behavior through visibility and mobility studies respectively. In order to achieve this objective, several isovists field simulations have been applied on the one hand, and a virtual forces based model has been introduced on the other ha...
Article
In the present joint research, authors are trying to correlate surroundings assessments with pedestrian movement behavior through visibility and mobility studies respectively. In order to achieve this objective, several isovists field simulations have been applied on the one hand, and a virtual forces based model has been introduced on the other ha...
Article
Full-text available
Street networks shape the urban layout that structures the city spaces and delineates homogeneous urban areas. We focus on the study of urban morphology from a structural analysis of the streets’ network. The work on a geographic model allows formalizing mathematically the street network by using graph theory. The structural analysis of street netw...
Chapter
Full-text available
Urban fabric characterization is very useful in urban design, planning, modeling and simulation. It is traditionally considered as a descriptive task mainly based on visual inspection of urban plans. Cartographic databases and geographic information systems (GIS) capabilities make possible the analytical formalization of this issue. This paper prop...
Chapter
Full-text available
The project objective is to develop an optimized methodology to assess the environmental impacts of urban mobility plans (UMP, in French PDU), taking into account their social and economic consequences. The main proposed methodology is based on a systemic approach: multi factor (air quality, noise, energy consumption, greenhouse gas emission) numer...
Book
A 3D city model is a digital representation of a city or an urban fabric, using data derived from multiple sources. It encompasses a large number of spatial objects that can gather various levels of detail, scales and can be of different classes, data models or structures. It is an important tool used in various fields such as urban planning and ma...
Conference Paper
Full-text available
The pedestrian mobility is a way to understand how a person might experience the void in between the buildings (this void defines a space portion as a shape) and therefore the urban fabric itself. The present paper aims to characterize landscape potentialities through pedestrian perception. Our proposal consists in building a set of sort of sensory...
Conference Paper
Full-text available
The pedestrian mobility is a way to understand how a person might experience the void in between the buildings (this void defines a space portion as a shape) and therefore the urban fabric itself. The present paper aims to characterize landscape potentialities through pedestrian perception. Our proposal consists in building a set of sort of sensory...
Conference Paper
Full-text available
Through interacting with urban and architectural spaces, pedestrian pathway‟s ambient fingerprints delineate ambiences with identifiable characteristics, thus characterizing landscape perception potentialities. Based on a measure of the surrounding open spaces using isovists, our proposal consists in building a sensory Digital Terrain models (DTM)...
Conference Paper
Full-text available
The streets' network shapes the urban layout that structures the city space and delineates homogeneous urban areas. Structural analysis of the streets' network is very useful because it usually produces additional semantic information (about urban dynamics). This allows the enrichment of spatial data. The topological and/or geometric characteristic...
Chapter
Full-text available
Partial isovist fields are useful methods to analyze the urban morphology taking into account the visual perception of the pedestrian. However, as previous studies involve a constant visual aperture angle all along the pathway, this chapter presents an adaptative method of aperture angular variation according to urban morphology properties. Apertur...
Article
Full-text available
Sustainable development objectives are mainly concerned with moving practices in urban design. Within this framework, Ambioflux project states on urban ambiences underlying feeling studies during pedestrian walks, in the context of urban project city qualification. Through environmental, ecosystemic, psychological and anthropological formulation of...
Article
Full-text available
Dans l’optique de la réalisation des objectifs du développement durable, les pratiques de mobilité jouent un rôle prépondérant dans le design urbain. Dans ce cadre, le projet de recherche exploratoire Ambioflux propose d’étudier la question du ressenti des ambiances urbaines en situation de mobilité douce (déplacement piéton) dans le contexte de re...
Conference Paper
Full-text available
The aim of this paper is to couple the isovists field (a useful tool to determine the surroundings) with a classical digital signal processing method so as to classify the open spaces all along a pedestrian pathway and identify some urban patterns. Indeed, it could be of a great interest to determine automatically the type of surrounding spaces to...
Book
Full-text available
The project objective is to develop an optimized methodology to assess the environmental impacts of urban mobility plans (UMP, in French PDU), taking into account their social and economic consequences. The main proposed methodology is based on a systemic approach: multi factor (air quality, noise, energy consumption, greenhouse gas emission) numer...
Article
The project objective is to develop an optimized methodology to assess the environmental impacts of urban mobility plans (UMP, in French PDU),taking into account their social and economic consequences. The main proposed methodology is based on a systemic approach : multi-factor (air quality, noise, energy consumption, greenhouse gas emission) numer...
Article
Full-text available
In the specific context of the Territorial Intelligence, taking some socio-ecological foresight constraint into account, there is a clear requirement of an advanced Geographic Information System with semantic abilities. Indeed, being able to overlay and do some geoprocessing on several spatial thematic layers is a sine qua non but not enough condit...