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See detailIncorporating trip chaining within online demand estimation
Cantelmo, Guido; Qurashi, Moeid; Prakash, Arun et al

in Transportation Research Procedia (2019), 38

Time-dependent Origin–Destination (OD) demand flows are fundamental inputs for Dynamic Traffic Assignment (DTA) systems and real-time traffic management. This work introduces a novel state-space framework ... [more ▼]

Time-dependent Origin–Destination (OD) demand flows are fundamental inputs for Dynamic Traffic Assignment (DTA) systems and real-time traffic management. This work introduces a novel state-space framework to estimate these demand flows in an online context. Specifically, we propose to explicitly include trip-chaining behavior within the state-space formulation, which is solved using the well-established Kalman Filtering technique. While existing works already consider structural information and recursive behavior within the online demand estimation problem, this information has been always considered at the OD level. In this study, we introduce this structural information by explicitly representing trip-chaining within the estimation framework. The advantage is twofold. First, all trips belonging to the same tour can be jointly calibrated. Second, given the estimation during a certain time interval, a prediction of the structural deviation over the whole day can be obtained without the need to run additional simulations. The effectiveness of the proposed methodology is demonstrated first on a toy network and then on a large real-world network. Results show that the model improves the prediction performance with respect to a conventional Kalman Filtering approach. We also show that, on the basis of the estimation of the morning commute, the model can be used to predict the evening commute without need of running additional simulations. [less ▲]

Detailed reference viewed: 91 (3 UL)
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See detailIncorporating trip chaining within online demand estimation
Cantelmo, Guido; Qurashi, Moeid; Prakash, Arun et al

in Transportation Research. Part B, Methodological (2019)

Time-dependent Origin–Destination (OD) demand flows are fundamental inputs for Dy- namic Traffic Assignment (DTA) systems and real-time traffic management. This work in- troduces a novel state-space ... [more ▼]

Time-dependent Origin–Destination (OD) demand flows are fundamental inputs for Dy- namic Traffic Assignment (DTA) systems and real-time traffic management. This work in- troduces a novel state-space framework to estimate these demand flows in an online con- text. Specifically, we propose to explicitly include trip-chaining behavior within the state- space formulation, which is solved using the well-established Kalman Filtering technique. While existing works already consider structural information and recursive behavior within the online demand estimation problem, this information has been always considered at the OD level. In this study, we introduce this structural information by explicitly representing trip-chaining within the estimation framework. The advantage is twofold. First, all trips belonging to the same tour can be jointly calibrated. Second, given the estimation during a certain time interval, a prediction of the structural deviation over the whole day can be obtained without the need to run additional simulations. The effectiveness of the proposed methodology is demonstrated first on a toy network and then on a large real-world net- work. Results show that the model improves the prediction performance with respect to a conventional Kalman Filtering approach. We also show that, on the basis of the estimation of the morning commute, the model can be used to predict the evening commute without need of running additional simulations. [less ▲]

Detailed reference viewed: 60 (2 UL)
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See detailIndoor positioning and floor plan based ground truth: Can you really click where you are?
Popleteev, Andrei UL

in 15th International Conference on Mobile and Ubiquitious Multimedia (MUM-2016) (2016, December)

The increasing accuracy of indoor positioning systems requires an appropriately accurate evaluation, which compares system outputs with the known coordinates of test locations --- the ground truth ... [more ▼]

The increasing accuracy of indoor positioning systems requires an appropriately accurate evaluation, which compares system outputs with the known coordinates of test locations --- the ground truth. Although ground truth data are rarely (if ever) tested, they are traditionally assumed to be perfectly accurate. However, even small errors introduced by inaccurate ground truth need to be taken into account for fair evaluation and comparison between modern high-resolution positioning systems. In this paper we analyze the quality of ground truth data provided by clicking on an interactive floor plan (a method employed by such classical systems as RADAR and Horus). Experimental results show that this method has high precision but low accuracy, and high systematic errors make it unsuitable for evaluation of fine-grained localization systems. [less ▲]

Detailed reference viewed: 147 (3 UL)
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See detailIndustry 4.0 – Implementation of an automated assembly line in a wooden modular house production plant: The case Leko Labs
de Vincenzo, Vincenzo UL; Hichri, Bassem UL; Plapper, Peter UL

in De vincenzo, Vincenzo; Hichri, Bassem; Plapper, Peter (Eds.) Robotix-Academy Conference for Industrial Robotics (RACIR) 2018 (2018, November)

Detailed reference viewed: 201 (10 UL)
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See detailInference of switched biochemical reaction networks using sparse bayesian learning
Pan, Wei UL; Yuan, Y.; Sootla, A. et al

in The proceedings of the 7th European Conference on Machine Learning and Principles and Practice of Knowledge Discovery in Databases (ECML/PKDD) (2014)

This paper proposes an algorithm to identify biochemical reaction networks with time-varying kinetics. We formulate the problem as a nonconvex optimisation problem casted in a sparse Bayesian learning ... [more ▼]

This paper proposes an algorithm to identify biochemical reaction networks with time-varying kinetics. We formulate the problem as a nonconvex optimisation problem casted in a sparse Bayesian learning framework. The nonconvex problem can be efficiently solved using Convex-Concave programming. We test the effectiveness of the method on a simulated example of DNA circuit realising a switched chaotic Lorenz oscillator. [less ▲]

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See detailThe influence of fracture geometry variation on non-Darcy flow in fractures under confining stresses
Chen, Yuedu; Lian, Haojie UL; Liang, Weiguo et al

in International Journal of Rock Mechanics and Mining Sciences (2018), 113

To investigate the influence of geometric characteristics of deformable rough fractures under confining stresses on the behaviors of non-Darcy flow, four fractured sandstone specimens were used for ... [more ▼]

To investigate the influence of geometric characteristics of deformable rough fractures under confining stresses on the behaviors of non-Darcy flow, four fractured sandstone specimens were used for hydraulic tests in the experiments. According to the experimental results of the relationships between the hydraulic gradient and the flow rate, it is demonstrated that the Forchheimer's equation can offer a good description of the non-Darcy flow in rough fractures. In addition, the coefficients A and B in Forchheimer's equation are sensitive to the fracture geometric characteristics, and their values also increase as the confining stress rises, mainly owing to the reduction of the hydraulic aperture and the heterogeneous distribution of the interconnected void areas with the confining stress rising. Then, the surface and interior geometric properties of rough fractures were quantitatively characterized with the peak asperity height and the box-counting fractal dimension of the heterogeneous distribution of the interconnected void areas, respectively. Furthermore, an empirical relationship between the fractal dimension D and the fracture apertures was constructed according to the experimental results. Lastly, a quantitative model was proposed to represent the relationship between the fracture geometric characteristics and the non-Darcy coefficient . This model was further used to link the non-linear coefficient of Forchheimer's equation and the critical Reynold number with the fracture geometric characteristics. The proposed models were validated by the experimental data and would be helpful to characterize the non-Darcy flow behavior in rough fractures under various confining stresses. [less ▲]

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See detailINFLUENCE OF PISTON DISPLACEMENT ON THE SCAVENGING AND SWIRLING FLOW IN TWO-STROKE DIESEL ENGINES
Obeidat, Anas UL; Haider, Sajjad; Ingvorsen, K.M. et al

in 23rd Nordic Seminar on Computational Mechanics NSCM-23 (2010)

Detailed reference viewed: 45 (3 UL)
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See detailInfluence of piston position on the scavenging and swirling flow in two-stroke Diesel engines
Obeidat, Anas UL; Haider, S.; Meyer, K.E. et al

in EUROMECH Colloquium 525 - Instabilities and transition in three-dimensional flows with rotation (2011, June 21)

Detailed reference viewed: 38 (8 UL)
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See detailThe influence of the Design Task Description on the course and outcome of idea generation meetings
Gericke, Kilian UL; Schmidt-Kretschmer, Michael; Blessing, Lucienne UL

in McDonnell, Janet; Lloyd, Peter (Eds.) About: Designing - Analysing Design Meetings (2009)

This paper presents the results of an explorative, comparative protocol analysis of two design meetings that focused on identifying how the style of the Design Task Description influences the course and ... [more ▼]

This paper presents the results of an explorative, comparative protocol analysis of two design meetings that focused on identifying how the style of the Design Task Description influences the course and the outcome of an idea generation meeting. A framework is used to allocate potential influencing factors, including the DTD, and to discuss the various relationships and influences in order to understand the differences in course and outcome of the meetings. The style of the DTD was found to influence the length of the analysis phase and lead to differences in the course of the two idea generation meetings and to a higher idea generation rate. [less ▲]

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See detailInfluence of the microstructure on the stress state of solder joints dusing thermal cycling
Menk, A.; Bordas, Stéphane UL

in Proceedings of 10th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems, EuroSimE 2009 (2009)

The lifetime of a solder joint is mainly determined by its creep behaviour. Creep arises from the stresses inside the solder joints as a consequence of the thermomechanical mismatch of the board and the ... [more ▼]

The lifetime of a solder joint is mainly determined by its creep behaviour. Creep arises from the stresses inside the solder joints as a consequence of the thermomechanical mismatch of the board and the substrate. The stress state is heavily influenced by the anisotropy of tin. To understand the damage process in solder joints, the influence of the anisotropic microstructure must be understood. In this paper the influence of different grain sizes, shapes and orientations on the stress state is evaluated, based on numerical experiments. [less ▲]

Detailed reference viewed: 39 (2 UL)
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See detailInsider Threats to Information Security, Digital Espionage, and Counter-Intelligence
You, Ilsun; Lenzini, Gabriele UL; De Santis, Alfredo

in IEEE Systems Journal (2017), 11(2),

Detailed reference viewed: 100 (19 UL)
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See detailAn integrated approach to adaptive anticipatory traffic control and parameter estimation
Huang, Wei; Tampere, Chris M.J.; Viti, Francesco UL

in Proceedings of the MT-ITS Conference (2015, June)

Detailed reference viewed: 50 (0 UL)
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See detailAn integrated approach to apdative anticipatory traffic control and parameter estimation
Huang, Wei; Tampere, Chris M.J.; Viti, Francesco UL

in Proceedings of the MT-ITS Conference (2015, June)

Detailed reference viewed: 80 (1 UL)
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See detailAn integrated design-analysis framework for three dimensional composite panels
Nguyen, Vinh-Phu; Kerfriden, Pierre; Bordas, Stéphane UL et al

in Computer-Aided Design (2014)

We present an integrated design-analysis framework for three dimensional composite panels. The main components of the proposed framework consist of (1) a new curve/surface offset algorithm and (2) the ... [more ▼]

We present an integrated design-analysis framework for three dimensional composite panels. The main components of the proposed framework consist of (1) a new curve/surface offset algorithm and (2) the isogeometric concept recently emerged in the computational mechanics community. Using the presented approach, finite element analysis of composite panels can be performed with the only input is the geometry representation of the composite surface. In this paper, non-uniform rational B-splines (NURBS) are used to represent the panel surfaces. A stress analysis of curved composite panel with stiffeners is provided to demonstrate the proposed framework. [less ▲]

Detailed reference viewed: 277 (6 UL)
See detailDer Integrated Function Modelling (IFM) Framework
Eisenbart, Boris UL; Gericke, Kilian UL; Blessing, Lucienne UL

Article for general public (2013)

Detailed reference viewed: 89 (5 UL)
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See detailAn Integrated Perspective on Traffic Management and Logistic Optimization
Amaral, R. R.; Aghezzaf, E.-H.; Rinaldi, Marco UL et al

in Proceedings of the 18th IEEE International Conference on Intelligent Transportation Systems, ITSC 2015 (2015)

Traffic Management and Logistic Optimization have been extensively studied as two separate classes of problems, for which numerous methodologies, mathematical models and algorithmic solutions were made ... [more ▼]

Traffic Management and Logistic Optimization have been extensively studied as two separate classes of problems, for which numerous methodologies, mathematical models and algorithmic solutions were made available in literature. However, little attention has been devoted to the interactions between the variables involved in these problems and the consequences of the decision making processes carried independently by Traffic Managers and Logistic Players. We believe this to be of considerable importance, since partial or incomplete knowledge on one another's decisions might yield sub-optimality for either or both of them. In this work, we propose an integrated view on both classes of problems, providing mathematical formulations to support the assessment of the impact which the two players may have on each other. © 2015 IEEE. [less ▲]

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See detailIntegrating Different Functional Modeling Perspectives
Eisenbart, Boris UL; Qureshi, Ahmed Jawad UL; Gericke, Kilian UL et al

in Charkrabarti, Amaresh; Prakash, Raghu (Eds.) ICoRD'13, Global Product Development (2013)

The paper proposes a modular functional modeling framework, which aims at integrating the different functional modeling perspectives, relevant to different disciplines. The results of two extensive ... [more ▼]

The paper proposes a modular functional modeling framework, which aims at integrating the different functional modeling perspectives, relevant to different disciplines. The results of two extensive literature studies on diverse functional modeling approaches proposed in a variety of disciplines are consolidated. These studies identified specific needs for an integrated functional modeling approach to support interdisciplinary conceptual design. The presented framework aims at fulfilling these needs. It consists of a variety of associated views, represented through different matrices. This matrix-based representation facilitates the analysis of different functional modeling perspectives and their interdependencies. Finally, the implications of the presented approach are discussed. [less ▲]

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See detailIntegrating strong and weak discontinuities without integration subcells and example applications in an XFEM/GFEM framework
Natarajan, S.; Roy Mahapatra, D.; Bordas, Stéphane UL

in International Journal for Numerical Methods in Engineering (2010), 83(3), 269-294

Partition of unity methods, such as the extended finite element method, allows discontinuities to be simulated independently of the mesh (Int. J. Numer. Meth. Engng. 1999; 45:601-620). This eliminates the ... [more ▼]

Partition of unity methods, such as the extended finite element method, allows discontinuities to be simulated independently of the mesh (Int. J. Numer. Meth. Engng. 1999; 45:601-620). This eliminates the need for the mesh to be aligned with the discontinuity or cumbersome re-meshing, as the discontinuity evolves. However, to compute the stiffness matrix of the elements intersected by the discontinuity, a subdivision of the elements into quadrature subcells aligned with the discontinuity is commonly adopted. In this paper, we use a simple integration technique, proposed for polygonal domains (Int. J. Numer. Meth. Engng 2009; 80(1):103-134. DOI: 10.1002/nme.2589) to suppress the need for element subdivision. Numerical results presented for a few benchmark problems in the context of linear elastic fracture mechanics and a multi-material problem show that the proposed method yields accurate results. Owing to its simplicity, the proposed integration technique can be easily integrated in any existing code. © 2010 John Wiley & Sons, Ltd. [less ▲]

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See detailInteractions between residential and daily mobility: Luxembourg case study in the MOEBIUS project (extended abstract)
Gerber, Philippe; Caruso, Geoffrey UL; Cornélis, Eric et al

in Hesse, Markus; Caruso, Geoffrey; Gerber, Philippe (Eds.) et al Proceedings of the BIVEC-GIBET Transport Research Days 2013 (2013)

We present the modelling strategy of the research project MOEBIUS, which aims at simulating future urbanisation and commuting mobility, including modal split, under various planning conditions. MOEBIUS is ... [more ▼]

We present the modelling strategy of the research project MOEBIUS, which aims at simulating future urbanisation and commuting mobility, including modal split, under various planning conditions. MOEBIUS is similar in its objectives to a Land Use and Transport Interaction (LUTI) model, although very modular in its implementation and with ability to deal with very fine spatial resolution inputs and outputs. We simulate (i) the future potential urbanisation in Luxembourg, (ii) the population and its spatial distribution, and (iii) the daily mobility (commuting pattern and travel mode choice) at a disaggregated level. [less ▲]

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See detailInteraktive Transitionsforschung und Wissensgenerierung im Bereich nachhaltiges Bauen
JUNG ép. PRELLER, Bérénice UL; Affolderbach, Julia UL; Schulz, Christian UL et al

in PND online (2014), 2014(2), 1-14

Basierend auf den Erfahrungen eines internationalen Forschungsprojekts zu den institutionellen Rahmenbedingungen für Innovativität im nachhaltigen Bauen illustriert der Beitrag das Potenzial interaktiver ... [more ▼]

Basierend auf den Erfahrungen eines internationalen Forschungsprojekts zu den institutionellen Rahmenbedingungen für Innovativität im nachhaltigen Bauen illustriert der Beitrag das Potenzial interaktiver Methoden für die Produktion von »Transitionswissen«. Die frühe Einbindung von lokalen Praktikern, Unternehmern, Wissenschaftlern, politischen Entscheidungsträgern und Vertretern von Nichtregierungsorganisationen dient dabei nicht nur den Forschenden zur Exploration des jeweiligen Forschungskontexts, sondern schafft eine Plattform für produktiven Austausch von Wissen. Methodisch unterstützt durch interaktive Workshops sowie Delphi-basierte Feedback- und Validierungsrunden entsteht über die Projektlaufzeit ein wechselseitiger Lernprozess, der zusätzlich durch den Austausch von Erfahrungen aus vier Fallstudienregionen in Europa, Australien und Kanada inspiriert wird. Er liefert für alle Beteiligten wichtige Erkenntnisse über die Gestaltbarkeit von nachhaltigkeitsorientierten Transitionsprozessen im Baubereich. [less ▲]

Detailed reference viewed: 206 (12 UL)