References of "Teller, Jacques"
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See detailModelling Urban Expansion: A Multiple Urban-Densities Approach
El Saeid Mustafa, Ahmed Mohamed ULg; Saadi, Ismaïl ULg; Cools, Mario ULg et al

in Proceedings of GEOProcessing 2016 (2016, April 24)

Most existing spatio-temporal urban expansion models consider urban land-use as a binary process, through the identification of urban versus non-urban areas. The main aim of this study is to analyze and ... [more ▼]

Most existing spatio-temporal urban expansion models consider urban land-use as a binary process, through the identification of urban versus non-urban areas. The main aim of this study is to analyze and model the expansion of multiple urban densities in Wallonia, Belgium. To this end, this study employs a multinomial logistic regression model that enables to visualize the consequence of different urban densities expansion. Cadastral datasets of years 2000 and 2010 are used to set four urban classes (non-urban, low-density, medium-density and high-density urban). Besides, several socio-economic, geographic and political driving forces dealing with urban development were operationalized to create maps of urban expansion probability for each urban density class. These probability maps are then utilized to predict future urban expansions for years 2020 and 2030. The model is validated using relative operating characteristic method for different urban classes. Our results suggest that different urban densities expansions are mainly linked to zoning status, neighboring areas that are urban and accessibility. Most importantly, this study highlights that the contribution of different driving forces to urban expansion process varies along with urban density. [less ▲]

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See detailContribution of future urbanisation expansion to flood risk changes
Bruwier, Martin ULg; Mustafa, Ahmed; Archambeau, Pierre ULg et al

Conference (2016, April)

The flood risk is expected to increase in the future due to climate change and urban development. Climate change modifies flood hazard and urban development influences exposure and vulnerability to floods ... [more ▼]

The flood risk is expected to increase in the future due to climate change and urban development. Climate change modifies flood hazard and urban development influences exposure and vulnerability to floods. While the influence of climate change on flood risk has been studied widely, the impact of urban development also needs to be considered in a sustainable flood risk management approach. The main goal of this study is the determination of the sensitivity of future flood risk to different urban devel~ opment scenarios at a relatively short-time horizon in the River Meuse basin in Wallonia (Belgium). From the different scenarios, the expected impact of urban development on flood risk is assessed. Three urban expansion scenarios are developed up to 2030 based on a coupled cellular automata (CA) and agent-based (AB) urban expansion model: (i) business-as-usual, (ii) restrictive and (m) extreme expansion scenarios. The main factor controlling these scenarios is the future urban land demand. Each urban expansion scenario is developed by considering or not high and/or medium flood hazard zones as a constraint for urban development. To assess the model's performance, it is calibrated for the Meuse River valley (Belgium) to simulate urban expansion between i990 and 2000. Calibration results are then assessed by comparing the 2000 simulated land-use map and the actual 2000 land-use map. The flood damage estimation for each urban expansion scenario is determined for five flood discharges by overlaying the inundation map resulting from a hydraulic computation and tlte urban expansion map and by using damage curves and specific prices. The hydraulic model Wolt‘2D has been extensively validated by comparisons between observations and computational results during flood event .This study focuses only on mobile and immobile prices for urban lands, which are associated to the most severe damages caused by floods along the River Meuse. These findings of this study offers tools to drive urban expansion based on numerous policies visions to mitigate future flood risk along the Meuse River. In particular, we assess the impacts on future flood risk of the prohibition of urban development in high and/or medium flood hazard zones. [less ▲]

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See detailUncertainty quantification in profile Hidden Markov Models (pHMM)-based activity sequences characterization
Saadi, Ismaïl ULg; Liu, Feng; El Saeid Mustafa, Ahmed Mohamed ULg et al

Poster (2016, April)

Recently, Liu et al. (2015) proposed a method to characterize activity sequences stemming from activity-travel diaries. The framework is structured as follows: from an extracted set of activity sequences ... [more ▼]

Recently, Liu et al. (2015) proposed a method to characterize activity sequences stemming from activity-travel diaries. The framework is structured as follows: from an extracted set of activity sequences, (a) the occurrence probabilities of the different activities are determined as well as their sequential order for aligning the activity sequences. Then, (b) profile Hidden Markov Models (pHMM) are defined based on the previous output. This technique is interesting given the fact that it is also able to include the irregular activities and, as a result, their derived trips. In this context, thinking about integration with an agent-based micro-simulation model requires, as a preliminary step, an uncertainty quantification analysis in order to measure the variability of the outcome. This approach is all the more necessary when agent-based micro-simulation is used to predict mid- and long-term system states. [less ▲]

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See detailAssessment of thermal comfort in existing pre-1945 residential building stock
Singh, M.K.; Attia, Shady ULg; Mahapatra, Sadha et al

in Energy (2016), 98(March), 122-134

The building sector is the third-largest consumer of primary energy in Belgium. This is partly because of the high percentage of old buildings (buildings constructed before 1945) in its building stock ... [more ▼]

The building sector is the third-largest consumer of primary energy in Belgium. This is partly because of the high percentage of old buildings (buildings constructed before 1945) in its building stock. Existing international standards on thermal comfort focus primarily on new construction and commercial buildings but tend to overlook old buildings. This study involves a thermal comfort assessment of fully functional (in use) residential buildings constructed before 1945 in Liège (Belgium). The research methodology is based on continuous long term monitoring of the indoor environment (November 2011 to May 2012) and followed by comfort surveys for selected houses in the city. The analysis of the collected data shows that family composition, envelope performance and the occupants' interaction with the indoor environment greatly affected occupant preferences and functioning of the indoor thermal environment. This study reveals that the occupants' interaction with the indoor thermal environment to restore comfortable thermal conditions varies throughout the day, by adjusting the temperature in different rooms of the house at different times of the day. This study argues that modern comfort standards have failed to estimate the comfort level in these old buildings and, if applied, they would lead to under estimation of their thermal comfort. [less ▲]

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See detailColor in the urban environment: A user-oriented protocol for chromatic characterization and the development of a parametric typology
Nguyen, Ngoc Luan ULg; Teller, Jacques ULg

in Color Research and Application (2016)

This article presents a user-oriented protocol that can be used to characterize chromatic attributes of an urban area. A need for both affordable and reliable assessment method of color has been observed ... [more ▼]

This article presents a user-oriented protocol that can be used to characterize chromatic attributes of an urban area. A need for both affordable and reliable assessment method of color has been observed in the field of urban design. The challenge is to provide statistical answers to these two questions: how is color organized, how does it develop its own structure in the city? The main purpose of the research is hence to investigate mean color types within the city via the implementation of a characterization tool; an urban area of the four main classes (historic center, periurban housing districts, working-class neighborhoods, and commercial zones) being characterized by a specific color palette, or a layout of specific color types. The developed instrumentation allows the assessment of the homogeneous and consistent features of an urban district. Their characterization protocol was tested through an application to several streets of the city of Liège (Belgium). [less ▲]

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See detailCharacterizing the morphology of suburban settlements: a method based on a semi-automatic classification of building clusters
de Smet, Fabian; Teller, Jacques ULg

in Landscape Research (2016), 41(1), 113-130

Urban sprawl is transforming our landscapes and rural areas at a spectacular pace. Measuring the strength of the phenomenon and proposing dynamic ways to delineate suburban areas have been the object of ... [more ▼]

Urban sprawl is transforming our landscapes and rural areas at a spectacular pace. Measuring the strength of the phenomenon and proposing dynamic ways to delineate suburban areas have been the object of much debate amongst scientists. The present article takes the view that, beyond measuring and delineating suburban areas, more efforts should be directed to qualifying the morphology of built settlements within these areas. Therefore it proposes a method based on a semi-automatic classification system of building clusters, designed to describe and interpret the phenomenon from a morphological perspective. This method is based on a combination of field surveys with numerical analyses of digital land cadastre maps. The application of this classification system to the suburban area around Liege reveals that, far from developing in a complete indifference of local conditions, contemporary suburban settlements are influenced by landscape structures inherited from the past. [less ▲]

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See detailImpacts of urban expansion on future flood damage: A case study in the River Meuse basin, Belgium
Mustafa, Ahmed; Bruwier, Martin ULg; Teller, Jacques ULg et al

in Erpicum, Sébastien; Dewals, Benjamin; Archambeau, Pierre (Eds.) et al Sustainable Hydraulics in the Era of Global Change: Advances in Water Engineering and Research (2016)

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See detailTrends in regional jobs-housing proximity based on the minimum commute: The case of Belgium
Saadi, Ismaïl ULg; Boussauw, Kobe; Teller, Jacques ULg et al

in Journal of Transport Geography (2016), 57

This paper investigates recent trends in the efficiency of the Belgian territorial structure in terms of commuting, at both the urban and regional scales. The minimum commute distance (MCD) and excess ... [more ▼]

This paper investigates recent trends in the efficiency of the Belgian territorial structure in terms of commuting, at both the urban and regional scales. The minimum commute distance (MCD) and excess rate (ER) are used to compare observed home-to-work trip lengths with an “optimal” alternative commuter pattern in which the sum of the distance traveled by the working population is minimized. The MCD is a proximity indicator that measures the spatial match between the labor market and the housing stock, which can also be regarded as an interesting indicator of potential border effects on travel behavior, especially in the inter-regional context of Belgium. An MCD calculation requires an origin–destination (OD) matrix and a distance matrix. In our Belgian case study, we employ a recent OD matrix (2010) originating from Social Security (ONSS) data. We compare this matrix with data from the 2001 and 1991 census surveys. In addition to identifying trends in jobs-housing proximity, the article assesses methodological implications regarding geographical scale arising from the use of the two data sources mentioned. Based on the available data, it was found that average actual commuting distance increased over both periods studied, while in general, growth rates of MCD are considerably lower than growth rates of the actual commuting distance. This indicates that the spatial proximity between the labor market and the housing stock in Belgium has declined over all periods studied, although this loss of spatial proximity only explains a small part of the increase of the actual commuting distance. Furthermore, we found that the comparison of excess commuting metrics between regions and time periods sets high standards on data requirements, in which uniformity in data collection and spatial level of aggregation is of great importance. Finally, as the main contribution of this study, the results demonstrate, through a statistical approach, that municipalities that are experiencing a higher-than-average increase in MCD and ER in one of the considered time frames are more likely to continue to exhibit a higher-than-average increase in the subsequent period. Therefore, the observed trends appear to be consistent over time. [less ▲]

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See detailCalibration of MATSim in the context of natural hazards in Liège (Belgium): Preliminary results
Saadi, Ismaïl ULg; El Saeid Mustafa, Ahmed Mohamed ULg; Teller, Jacques ULg et al

in Proceedings of the 12th Conference on Transport Engineering (2016)

In Belgium, river floods are among the most frequent natural disasters and they may cause important changes on travel demand. In this regard, we propose to set up a large scale scenario using MATSim for ... [more ▼]

In Belgium, river floods are among the most frequent natural disasters and they may cause important changes on travel demand. In this regard, we propose to set up a large scale scenario using MATSim for guarantying an accurate assessment of the river floods impact on the transportation systems. In terms of inputs, agent-based models require a base year population. In this context, a synthetic population with a respective set of attributes is generated as a key input. Afterwards, agents are assigned activity chains through an activity-based generation process. Finally, the synthetic population and the transportation network are integrated into the dynamic traffic assignment simulator, i.e. MATSim. With respect to data, households travel surveys are the main inputs for synthesizing the populations. Besides, a steady-state inundation map is integrated within MATSim for simulating river floods. To our knowledge, very few studies have focused on how river floods affect transportation systems. In this regard, this research will undoubtedly provide new insights in term of methodology and traffic pattern analysis under disruptions, especially with regard to spatial scale effects. The results indicate that at the municipality level, it is possible to capture the effects of disruptions on travel behavior. In this context, further disaggregation is needed in future studies for identifying to what extent results are sensitive to disaggregation. In addition, results also suggest that the target sub-population exposed to flood risk should be isolated from the rest of the travel demand to reach have more sensitive effects. [less ▲]

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See detailA framework to identify housing location patterns using profile Hidden Markov Models
Saadi, Ismaïl ULg; Liu, Feng; El Saeid Mustafa, Ahmed Mohamed ULg et al

in Advanced Science Letters (2016), 22(9), 2117-2121

The determination of comprehensive activity-travel patterns is important in the context of agent-based micro-simulation modelling. This paper presents an improved method based on profile Hidden Markov ... [more ▼]

The determination of comprehensive activity-travel patterns is important in the context of agent-based micro-simulation modelling. This paper presents an improved method based on profile Hidden Markov Models (pHMMs) able to include information related to the agents’ residential locations. As proposed in the framework of Liu et al. (2015), pHMMs only characterize activity-travel patterns from the activity sequences perspective. In this context, information related to the primary activity locations (e.g. home, work) is not available and, as a result, it cannot be extracted from the pHMMs themselves. With respect to this limitation, we propose to apply the framework of Liu et al. (2015) with an extension to include characterization of residential locations. Following the established guidelines, the activity sequences and their related residential locations are extracted from the activity-travel diaries in order to estimate the regularity of the activities as well as their sequential order. Subsequently, within each residential activity, we include a categorization at an aggregate level (provinces). The methodology is powerful as it characterizes any length of sequence, allowing the generation of unlimited agent plans with information about residential location. Regarding data collection, the activity-travel diaries are provided by the Belgian Household Daily Travel Survey (2010). The results obtained after the simulations indicate a good match between the predicted and observed residential locations at both the national and provincial levels. [less ▲]

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See detailcolour in the urban environment: a tool for the chromatic analysis of spatial coherence
Nguyen, Ngoc Luan ULg; Teller, Jacques ULg

in XII Conferenza del Colore : Book of Abstracts (2016)

Colour is an essential component of urban landscapes that inform us about the status and history of a place, through relations of dominance, integration or uniformity that can be observed between its ... [more ▼]

Colour is an essential component of urban landscapes that inform us about the status and history of a place, through relations of dominance, integration or uniformity that can be observed between its built components. It can be shown that many traditional cities appear to be « chromatically polynuclear » in Europe and that each epoch, each type of urban area, each city is characterized by its own colour palette, which can be more or less homogeneous. Still the urban mutations observed in the second part of the 20th century generated a significant increase in the entropy of contemporary extentions of cities, which induced a loss of meaning and coherence by dislocating permanent structures set up in the past that maintained some integrity of urban landscapes. City entrances for instance, where old buildings mix with commercial equipment, show an unprecedented heterogeneity in their colour palettes. Few studies have focused on the description of these emerging configurations. Their complexity both in formal and chromatic aspects is certainly a difficulty from the perspective of their characterization. This can be explained by the lack of tools for an objective analysis of colour palettes in an urban environment. Given this lack of both affordable and reliable assessment method of colour that has been observed in the field of urban design, the research presents the implementation of a tool that can be used to characterize chromatic attributes of an urban area. The challenge is to provide statistical and quantitative answers to these questions: how is colour organized, how does it develop its own structure in the city? How can colour appear as an indicator of homogeneity and spatial coherence? As colour can be represented in a tri-dimensional space, we use a k-means statistical clustering technique, based on a data partitioning algorithm, to produce a chromatic classification of building facades. Once the chromatic categories are defined through the developed assessment method, the question of spatial coherence is investigated using Shannon entropy. Our method was tested through an application to several urban fragments of the city of Liège (Belgium) and the research highlights the differences between historic urban areas (historic center, 19th century developments) with new urban configurations (city entrances, commercial and periurban zones). [less ▲]

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See detailBelgium: The Use of MATSim within an Estimation Framework for Assessing Economic Impacts of River Floods
Saadi, Ismaïl ULg; Teller, Jacques ULg; Cools, Mario ULg

in Horni, Andreas; Nagel, Kai; Axhausen, Kay W. (Eds.) The Multi-Agent Transport Simulation MATSim (2016)

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See detailModelling children’s mobility and school commuting: a review and key challenges for further research
Marique, Anne-Françoise ULg; Teller, Jacques ULg; Cools, Mario ULg

Poster (2016)

Children’s mobility and school travelling are relatively underdeveloped in transport research, especially when compared with commuting to work. Despite it is often argued that a profound analysis of ... [more ▼]

Children’s mobility and school travelling are relatively underdeveloped in transport research, especially when compared with commuting to work. Despite it is often argued that a profound analysis of school-travel patterns has the potential to generate many important insights that may impact transport-system policy and management, the modelling of children mobility, is still in an early stage of development and children are often only considered as constraints to adults’ mobility. In this paper, we argue that innovative modelling frameworks that were recently developed in the field of transportation could be adapted and applied to the mobility of children in order to develop both novel scientific insights and inform the development of policies aiming at increasing active and independent mobility of children, in a broader vision of sustainability. [less ▲]

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See detailÉvaluation des impacts économiques indirects selon un scénario de risque d’inondation
Saadi, Ismaïl ULg; El Saeid Mustafa, Ahmed Mohamed ULg; Teller, Jacques ULg et al

in Recueil des articles des 34èmes Rencontres Universitaires de Génie Civil de l'AUGC (2016)

In this paper, we propose an integrated framework to estimate the indirect economic impact due to flood risk in Belgium. By taking into account the land-use change and different scenarios of climate ... [more ▼]

In this paper, we propose an integrated framework to estimate the indirect economic impact due to flood risk in Belgium. By taking into account the land-use change and different scenarios of climate change, the economic impact can be estimated at the micro-scale level using an Input-Output (I-O) approach. I-O is an econometric model that represents the structure of an economy in the form of a Production-Consumption (P-C) matrix. From a physical point of view, it corresponds to commodity flows between different sectors classified according to the NACE code. This approach is implemented to describe and to better understand the propagation of higher order damage through the entire economic structure. This tool can be used to take strategic decisions in the case of transport and land-use policies within vulnerable areas. [less ▲]

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See detailHidden Markov Model-based population synthesis
Saadi, Ismaïl ULg; El Saeid Mustafa, Ahmed Mohamed ULg; Teller, Jacques ULg et al

in Transportation Research. Part B : Methodological (2016), 90

Micro-simulation travel demand and land use models require a synthetic population, which consists of a set of agents characterized by demographic and socio-economic attributes. Two main families of ... [more ▼]

Micro-simulation travel demand and land use models require a synthetic population, which consists of a set of agents characterized by demographic and socio-economic attributes. Two main families of population synthesis techniques can be distinguished: (a) fitting methods (iterative proportional fitting, updating) and (b) combinatorial optimization methods. During the last few years, a third outperforming family of population synthesis procedures has emerged, i.e., Markov process-based methods such as Monte Carlo Markov Chain (MCMC) simulations. In this paper, an extended Hidden Markov Model (HMM)-based approach is presented, which can serve as a better alternative than the existing methods. The approach is characterized by a great flexibility and efficiency in terms of data preparation and model training. The HMM is able to reproduce the structural configuration of a given population from an unlimited number of micro-samples and a marginal distribution. Only one marginal distribution of the considered population can be used as a boundary condition to “guide” the synthesis of the whole population. Model training and testing are performed using the Survey on the Workforce of 2013 and the Belgian National Household Travel Survey of 2010. Results indicate that the HMM method captures the complete heterogeneity of the micro-data contrary to standard fitting approaches. The method provides accurate results as it is able to reproduce the marginal distributions and their corresponding multivariate joint distributions with an acceptable error rate (i.e., SRSME=0.54 for 6 synthesized attributes). Furthermore, the HMM outperforms IPF for small sample sizes, even though the amount of input data is less than that for IPF. Finally, simulations show that the HMM can merge information provided by multiple data sources to allow good population estimates. [less ▲]

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See detailAn integrated framework for forecasting travel behavior using Markov Chain Monte-Carlo simulation and profile Hidden Markov Models
Saadi, Ismaïl ULg; El Saeid Mustafa, Ahmed Mohamed ULg; Teller, Jacques ULg et al

in Proceedings of the 95th Annual Meeting of the Transportation Research Board (2016)

Recent advances in agent-based micro-simulation modelling have further underlined the importance of a thorough full synthetic population procedure to guarantee a correct characterization of the true ... [more ▼]

Recent advances in agent-based micro-simulation modelling have further underlined the importance of a thorough full synthetic population procedure to guarantee a correct characterization of the true population. We propose an integrated approach including Markov Chain Monte Carlo (MCMC) simulation and profiling based methods to catch the complexity and the diversity of agents of the true population through representative micro samples. The population synthesis method is capable of building the joint distribution of a given population with its corresponding marginal distributions (e.g. age, gender, socio-professional status etc.) using complete, partial conditional probabilities or both of them at the same time. Particularly, the estimation of socio-demographic variables and characterization of daily activity-travel patterns are included within the framework. Data stemming from the 2010 Belgian Household Daily Travel Survey (BELDAM) are used to calibrate the modelling framework. We illustrate that this framework catches in an efficient way the behavioral heterogeneity of travelers. Furthermore, we show that the proposed framework is adequately adapted to build large scale micro-simulation scenarios of transportation and urban systems. [less ▲]

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See detailFiscalité et Aménagement du Territoire
Bianchet, Bruno ULg; Xhignesse, Guillaume ULg; Copée, Pierre ULg et al

Report (2015)

Cette recherche consiste en une réflexion sur la fiscalité en tant qu'outil d'aménagement du territoire et en tant que moyen de recontrer les défis du développement territorial, dans le contexte wallon ... [more ▼]

Cette recherche consiste en une réflexion sur la fiscalité en tant qu'outil d'aménagement du territoire et en tant que moyen de recontrer les défis du développement territorial, dans le contexte wallon. Elle s'intègre dans le contexte des débats qui entourent la sixième réforme de l'Etat belge. Elle a pour objectif l'établissement d'un cadre utilisable pour l'évaluation de certains effets territoriaux suite à la mise en oeuvre ou à la modification de politiques fiscales. In fine, elle aboutira à des propositions d'adaptation ou de mise au point de nouvelles mesures en vue de rencontrer les défis territoriaux. Afin d'atteindre ces objectifs, elle se concentre également sur la mise en évidence des liens existants entre le système fiscal en place et certains défis territoriaux. Son objet est restreint au logement et à l'aménagement en lien avec le logement. [less ▲]

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See detailModelling Agents’ Behavior in the Context of River Floods: An Ant Colony based Approach
Saadi, Ismaïl ULg; El Saeid Mustafa, Ahmed Mohamed ULg; Teller, Jacques ULg et al

Conference (2015, September)

This paper presents a model for understanding short-term travelers’ behavior in the context of river floods. In several cities, river floods are considerably affecting urban transportation systems. In ... [more ▼]

This paper presents a model for understanding short-term travelers’ behavior in the context of river floods. In several cities, river floods are considerably affecting urban transportation systems. In this regard, decision makers need comprehensive models to define efficient risk management strategies. The dynamic nature of this problem requires an algorithm able to deal with traffic redirecting during the micro-simulation process. Furthermore, a transportation network contains a significant number of links and nodes which lead to large computation times. In this regard, an Ant Colony Optimization (ACO) algorithm is proposed to solve such combinatorial problems. In a basic ACO, some ants/agents might push the algorithm to converge toward non-optimal solutions. In this context, a MAX-MIN Ant System (AS) approach is included in the algorithm to stimulate the best solutions. In addition, the discrete choice model is adapted to allow more behavioral reactions regarding simulated river floods. [less ▲]

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