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See detailElectric Power Network State Tracking from Multirate Measurements
Alcaide-Moreno, Boris; Fuerte-Esquivel, Claudio; Glavic, Mevludin ULiege et al

in IEEE Transactions on Instrumentation and Measurement (in press)

This paper proposes a novel tracking state estimator to process both fast-rate synchronized phasor and slow rate SCADA measurements. The former are assumed to be in limited number. The latter are ... [more ▼]

This paper proposes a novel tracking state estimator to process both fast-rate synchronized phasor and slow rate SCADA measurements. The former are assumed to be in limited number. The latter are exploited as and when they arrive to the control center. In order to restore observability, after each execution of the tracking state estimator, forecasted SCADA measurements are used as pseudo-measurements in the next estimation. An event detection analysis allows assessing if the system is in quasi steady-state. If so, an innovation analysis is performed to identify and eliminate erroneous SCADA measurements. The system state is computed by Hachtel’s augmented matrix method. The option of exploiting time-tagged SCADA measurements is also considered. The method is illustrated through detailed dynamic simulations of a test system evolving towards voltage collapse, with and without emergency control. [less ▲]

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See detailInvestigating the impact of river floods on travel demand based on an agent-based modeling approach: The case of Liège, Belgium
Saadi, Ismaïl ULiege; El Saeid Mustafa, Ahmed Mohamed ULiege; Teller, Jacques ULiege et al

in Transport Policy (in press)

In Belgium, river floods are among the most frequent natural disasters and they may have important consequences on travel demand. In order to better understand how the travel patterns vary, we propose to ... [more ▼]

In Belgium, river floods are among the most frequent natural disasters and they may have important consequences on travel demand. In order to better understand how the travel patterns vary, we propose to set up a large scale scenario based on MATSim for guarantying an accurate assessment of the impact of river floods on the transportation system. As inputs, the current agent-based model requires a base year population. A synthetic population with 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 MATSim. Regarding data, households travel surveys, OD matrix of Belgium have been used to set up the demand. For simulating river floods effects, a steady-state inundation map has been integrated within MATSim. In the current study, five scenarios have been tested where critical links are associated various levels of service, i.e. 10%, 25%, 50%, 75% and 100% (base case scenario). They are systematically compared to the standard scenario to estimate the deviations in terms of traffic patterns and travel times. The results suggest that compared to the standard scenario, the average trip travel time increased by 16.36%, 44.44%, 126.77% and 144.44% with respect to scenarios 75%, 50%, 25% and 10% respectively. Also, the traffic flows have been re-distributed more uniformly across the transportation network. Roads with important traffic volumes are subjected to a decrease of activity on the contrary of roads with low traffic volumes. A very few studies have focused on how river floods affect transportation systems, this paper provided new insights in term of methodology and traffic patterns analysis under disruptions. [less ▲]

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See detailDifferential contributions of default and dorsal attention networks to remembering thoughts and external stimuli from real-life events
Stawarczyk, David ULiege; Jeunehomme, Olivier ULiege; D'Argembeau, Arnaud ULiege

in Cerebral Cortex (in press)

Episodic memories are typically composed of perceptual information derived from the external environment and representations of internal states (e.g., one’s thoughts during prior episodes). To date ... [more ▼]

Episodic memories are typically composed of perceptual information derived from the external environment and representations of internal states (e.g., one’s thoughts during prior episodes). To date, however, research has mostly focused on the remembrance of external stimuli, such that little is known about how internal mentation is represented within episodic memory. In the present fMRI study, we examined the neural correlates of these two components of episodic memories using a novel method of cuing memories from photographs taken during real-life events. We found that, compared to corresponding semantic memory tasks, memories for internal thoughts and external elements were associated with activity in brain areas supporting episodic recollection. Most importantly, however, the two kinds of memories also showed differential activation in large-scale brain networks: the remembrance of external elements was associated with greater activity in the dorsal attention network, whereas memories of internal thoughts mainly recruited default network areas. These findings shed new light on the representation of internal and external aspects of prior experience within episodic memory. The default network may contribute to the reinstatement of thoughts experienced during past events, whereas the dorsal attention network may support the allocation of attention to visuo-spatial features within episodic memory representations. [less ▲]

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See detailEffect of Voltage Constraints on the Exchange of Flexibility Services in Distribution Networks
Mathieu, Sébastien ULiege; Olivier, Frédéric ULiege; Ernst, Damien ULiege et al

in Proceedings of the 9th Conference on Innovative Smart Grid Technology North America (ISGT 2018) (in press)

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See detailComparative assessment of phytochemical profiles and antioxidant properties of Tunisian and Egyptian anise (Pimpinella anisum L.) seeds
Bettaieb ép Rebey, Ines ULiege; Bourgou, Soumaya; Aidi Wannes, Wissem et al

in Plant Biosystems (in press)

Anis (Pimpinella anisum L.) seeds obtained from two geographic origins Tunisia (TAS) and Egypte (EAS) were studied regarding their biochemical composition and the antioxidant potential of their extracts ... [more ▼]

Anis (Pimpinella anisum L.) seeds obtained from two geographic origins Tunisia (TAS) and Egypte (EAS) were studied regarding their biochemical composition and the antioxidant potential of their extracts. The results showed that the highest value of oil was detected with TAS compared to that of EAS ones. Ten (10) fatty acids were identified for the two locations and petroselinic acid was the most prevalent in oil seeds and interestingly, TAS displayed a significantly higher level of this acid than EAS. Besides, TAS exhibited slightly higher essential oil yield than the Egyptian variety and that trans-anethole was the dominant for the two provenances. In both accessions, the highest total phenolic, flavonoid and tannin content was obtained with ethyl acetate fraction. Therefore, TAS exhibited higher chelating and reducing powers than EAS which may be due to a slightly different phenolic composition between the two accession seed extracts. The phenolic compositions of TAS and EAS revealed that ethyl acetate extracts showed higher proportions of naringin, chlorogenic acid and rosmarinic acid. However, ethanol extracts were richer in larcitrin, rosmarinic acid and cirsimartin. The overall results revealed that aniseeds might constitute a novel source of natural antioxidants and could be used as food additive. [less ▲]

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See detailSalinity impact on seed yield, polyphenols composition and antioxidant activity of Fennel (Foeniculum vulgarae Mill) extracts
Bettaieb ép Rebey, Ines ULiege; Bourgou, S.; Marzouk, B. et al

in Journal of new sciences (in press)

Recently, medicinal and aromatic plants have received much attention in several fields such agroalimentary, perfumes, pharmaceutical industries and natural cosmetic products. The consumption of herbal ... [more ▼]

Recently, medicinal and aromatic plants have received much attention in several fields such agroalimentary, perfumes, pharmaceutical industries and natural cosmetic products. The consumption of herbal medicines is widespread and is continuously increasing worldwide. Although, secondary metabolites in the medicinal and aromatic plants were fundamentally produced by genetic processing but, their biosynthesis is strongly influenced by environmental factors. Salinity is one of the major factors that affect essential oil biosynthesis and secretion (Heuer et al. 2002). In Tunisia, salt-affected soils cover about 10% of the total area of the country. Salinity led to biochemical disorders and can change plant behaviour regarding the biosynthesis of primary and secondary metabolites. Among all the secondary metabolites synthesized by plants, phenolic compounds are some of the most widespread. In this context, this research evaluated the effect of salinity on total and individual polyphenols contents as well as the antioxidant activities of fennel (Foeniculum vulgarae Mill.) seeds of two geographic origins, Tunisia (TFS) and Egypt (EFS). This plant is one of the most common aromatics in the Mediterranean kitchen. Plants were treated with different concentrations of NaCl treatment: 0, 50, and 75 mmoL. Plant growth was significantly reduced with the severity of saline treatment. This also caused important reductions in the seed yield and yield components. Besides, total polyphenol content was higher in treated seeds, and salinity improved the amount of individual phenolic compounds. Moreover, antioxidant activities of the extracts were determined by four different test systems, namely 2,2-diphenyl-1-picrylhydrazyl, β-carotene/linoleic acid chelating, and reducing power assays. The highest antioxidant activities were reveled in severe stressed plants for both TFS and EFS. In this case, fennel seeds produced under saline conditions may function as a potential source of antioxidant compounds, which could support the utilization of this plant in a large field of applications such as food industry. [less ▲]

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See detailPaper Formats of the Mamluk Period: The Contribution of Mamluk Chancery Paper
Bauden, Frédéric ULiege

in Journal of Islamic Manuscripts (in press)

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See detailLes motifs budgétaires dans le contentieux constitutionnel
Behrendt, Christian ULiege; Miny, Xavier ULiege

in Velandia Canosa, Eduardo Andres (Ed.) Proceedings and Works of the Third Wold Congress of International Justice (in press)

Research paper presented at the Third World Congress of Constitutional Justice, Bologna, Italy, October 10-12, 2017.

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See detailCharleroi, the 'placerelle'
Bianchi, Michaël ULiege

in Masterclass Bridges (in press)

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See detailEléments de réflexions à propos de l’occupation de la parcelle de la Schola del Traiano (IV, V, 15-16)
Morard, Thomas ULiege

in De Ruyt, Claire; Morard, Thomas; Van Haeperen, Françoise (Eds.) Ostia Antica. Nouvelles études et confrontation des recherches sur les quartiers occidentaux de la cité (in press)

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See detailTwo-loop-induced neutrino masses: A model-independent perspective
Aristizabal Sierra, Diego ULiege

in PoS - Proceedings of Science (in press)

We disucuss Majorana neutrino mass generation mechanisms at the two-loop order. After briefly reviewing the systematic classification of one-loop realizations, we then focus on a general two-loop ... [more ▼]

We disucuss Majorana neutrino mass generation mechanisms at the two-loop order. After briefly reviewing the systematic classification of one-loop realizations, we then focus on a general two-loop classification scheme which provides a model-independent catalog for neutrino mass models at the two-loop order [less ▲]

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See detailLe IIe style en reliefs : les ensembles de stucs de la Domus aux Bucranes à Ostia Antica
Morard, Thomas ULiege; Girard, Thibault

in Bragantini, Irene; Flazone, Stella; Fortini, Patrizia (Eds.) et al Pitture frammentarie di epoca romana da Roma e dal Lazio : nuove ricerche (in press)

The publication of the book Nani in Festa. Iconografia, religione e politica in Ostia durante il secondo triumvirato (C. Bocherens ed., Edipuglia, 2012) was the occasion to highlight the exceptional ... [more ▼]

The publication of the book Nani in Festa. Iconografia, religione e politica in Ostia durante il secondo triumvirato (C. Bocherens ed., Edipuglia, 2012) was the occasion to highlight the exceptional decorative system of the “Domus aux Bucranes” and, especially, to put forward the frieze of dwarfs and its interpretation. With the discovery of these paintings, in the œcus, we have discovered a remarkable collection of stuccos, until today remains unpublished. This article gives a first description and an initial analysis of the fragments of stucco. Their placement on the wall and their relationship with pavements, frescoes and painted ceilings are studied, as well as the iconography they carrying, in close relation with the context of the domus, and, more generally, with Ostia in the late-republican period. [less ▲]

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See detailL’emblématique de Louise de Savoie
Fagnart, Laure ULiege; Girault, Pierre-Gilles

in Armas e Troféus. Rivista de Historia, Heraldica, Genealogia (in press)

A l'occasion de cette étude, à la suite des travaux d'Anne-Marie Lecoq (1987), nous sommes revenus sur le discours héraldique de la comtesse et duchesse d'Angoulême, Louise de Savoie, l'influente mère de ... [more ▼]

A l'occasion de cette étude, à la suite des travaux d'Anne-Marie Lecoq (1987), nous sommes revenus sur le discours héraldique de la comtesse et duchesse d'Angoulême, Louise de Savoie, l'influente mère de François Ier. Nous avons présenté et explicité ses devises favorites, à savoir la cordelière, qui évoque autant le nœud de Savoie que la cordelière franciscaine, le vol, sans doute choisi puisque l’aile évoque le L de Louise par homophonie, le bouquet de lis ou le cygne « navré », mais aussi les écus et les monogrammes qui lui sont associés et qui ponctuent enluminures, tapisseries, bas-reliefs et éléments sculptés de l’architecture. Notre intention a été de montrer d’une part comment Louise de Savoie manifeste, par l’intermédiaire de ces signes emblématiques, son identité et son pouvoir, d’autre part comment elle construit, par leur biais, un patrimoine, mental, susceptible de renforcer son clan et ses héritiers. [less ▲]

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See detailConscience interne et connaissance de soi. Descartes et Brentano
Dewalque, Arnaud ULiege

in Pradelle, Dominique; Riquier, Camille (Eds.) Descartes et la phénoménologie (in press)

J'examine ici l’approche cartésiano-brentanienne de la conscience. Cette approche comporte une thèse psychologique ("tout ce qui est mental est conscient") et une double thèse épistémologique ("toute ... [more ▼]

J'examine ici l’approche cartésiano-brentanienne de la conscience. Cette approche comporte une thèse psychologique ("tout ce qui est mental est conscient") et une double thèse épistémologique ("toute conscience interne est évidente"/'aucune perception externe n'est évidente"). On a souvent considéré que ces thèses se heurtaient à d’imposantes difficultés et rendaient l’approche cartésiano-brentanienne de la conscience particulièrement problématique. Contre ces critiques, certains commentateurs ont récemment suggéré qu’on pouvait toutefois donner un sens acceptable à la thèse psychologique. Je voudrais suggérer, pour ma part, qu’on peut aussi donner un sens acceptable à la double thèse épistémologique. Dans la section 2, je reconstruit la position cartésiano-brentanienne en termes d'asymétrie épistémique entre perception interne et perception externe. Dans les sections 3 et 4, je discute les objections soulevées par Husserl et par Ryle, et je suggère que la théorie brentaniexnne permet de réfuter ces objections. [less ▲]

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See detailDetermining astrophysical parameters of quasars within the Gaia mission
Delchambre, Ludovic ULiege

Doctoral thesis (2018)

Quasars are one of the most peculiar types of objects in astronomy. The supermassive black hole these harbour effectively makes the surrounding matter radiates an enormous amount of energy before getting ... [more ▼]

Quasars are one of the most peculiar types of objects in astronomy. The supermassive black hole these harbour effectively makes the surrounding matter radiates an enormous amount of energy before getting in the vicinity of the black hole horizon out of which it will never escape. This ironically leads to the most luminous phenomenon in the Universe while being non-transient. It is hence quite natural to rely on these cosmic headlights, visible up to ages when the Universe was still very young, so as to achieve some of the currently most important cosmological applications, notably regarding the determination of the cosmological parameters $H_0$, $\Omega_\Lambda$ and $\Omega_m$. The Gaia mission, on its side, is one of a kind given the one billion of celestial objects it is intended to observe, among which more than half a million quasars are expected. Furthermore, owing to its exceptional astrometric precision, Gaia stands out to be extremely well suited for the detection of gravitational lens (GL) systems. In the latter, light rays coming from a distant background quasar are deflected by the presence of a massive galaxy being in the line-of-sight that leads to the production of multiple images of this background quasar upon a favourable alignment between the quasar, the galaxy and the observer. Supplemental constraints on the aforementioned cosmological parameters being then gained based on these GLs. Gaia hence provides an unprecedented opportunity to detect and characterize quasars as well as to identify GLs which ultimately bring a better understanding of the Universe we live in. This thesis is accordingly concerned with the development of software solutions dedicated to the determination of the astrophysical parameters (APs) of the quasars that Gaia will observe, on one hand, and to the recognition of the GLs among the billion of sources it will uncover, on the other hand. Although Gaia provides state-of-the-art astrometric and photometric observations, its capability in characterizing these celestial objects remains however restricted by the relatively low spectral resolution of the blue and red spectrophotometers upon which it is based as well as by the limited signal-to-noise ratio that is associated with faint objects, including quasars. In addition, the overwhelming amount of data that Gaia has to process translates into a stringent need for algorithms having both low numerical complexities as well as low memory usages. These restrictions and shortcomings along with the requirement for reliable APs were at the heart of this research that led to the development of two specifically designed methods that are the weighted principal components analysis and the weighted phase correlation method. The former of these methods allowed us to extract the most significant patterns out of quasars with a view of using these in the production of a spectral library of quasars as observed by Gaia. These were subsequently used in a fast and automated procedure designed to guess the redshift of the quasars within the Gaia mission through the latter mentioned method. Other APs that are the slope of the quasar continua, the total equivalent width of their emission lines and whether these encompass broad absorption lines or not, being then concurrently derived based on the results of these methods. Finally, the identification of GL candidates relies on the recognition of the structures and symmetries that are observed within lensed images through supervised learning methods. The specific method we choose to use, based on extremely randomized trees, was shown to yield a low contamination rate on simulated configurations composed of three images as well as a very high probability of detection in cases of four image configurations. Real observations out of the first Gaia data release were processed and resulted in the identification of candidates having three potentially lensed images which are currently waiting for confirmation using ground-based facilities. [less ▲]

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See detailRiparian characterization from remote sensing in a multiple scale perspectives. A few examples
Piégay, Hervé; Michez, Adrien ULiege; Raepple, Bianca et al

Conference (2018, October 18)

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See detailAdaptive Facades Performance Assessment, interviews with facade experts
Attia, Shady ULiege; Bilir, Senem; Safy, Taha

Report (2018)

Adaptive facades can ensure step-change progresses in the energy efficiency and the use of renewable energy while improving the comfort of the occupants. Therefore, the purpose of this structured ... [more ▼]

Adaptive facades can ensure step-change progresses in the energy efficiency and the use of renewable energy while improving the comfort of the occupants. Therefore, the purpose of this structured interview is to assess advantages, disadvantages and future expectations considering the adaptive facades. This work is a part of actions of The COST Action TU1403 Adaptive Façade Network. The objective of this report is to gain an understanding of how experts currently define adaptive façade systems, which simulation tools they use, the major strengths, weaknesses, opportunities and treats of adaptive façade systems, key performance indicators they use and their vision for the future of adaptive facades. With this information gathered, it is anticipated that adaptive façade professionals will carry on assessment of adaptive facades. A qualitative study design was employed, using semi-structured interviews. Interviewees working in academia and practice were selected. The interviewees represented the range of possible adaptive facade professionals, from researchers and designers considered optimization in the assessment of adaptive facades. Also, every interviewed expert was asked to approve their responses and add any additional comment to their answers. [less ▲]

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See detailEvaluation of Adaptive Facades: A case study of the Swiss School in Dubai
Bilir, Senem; Attia, Shady ULiege

in Luible, Andreas (Ed.) Adaptive Facades (2018, October)

Adaptive facades are performance based envelopes that are able to respond dynamically to climatic conditions. One of the recognized adaptive façade technologies is electrochromic glazing. However, very ... [more ▼]

Adaptive facades are performance based envelopes that are able to respond dynamically to climatic conditions. One of the recognized adaptive façade technologies is electrochromic glazing. However, very few studies evaluated the performance of electrochromic glazing on the building level. Therefore, we selected a case study of a certified educational building with a nearly zero energy building performance that includes an electrochromic facade. The overall aim of the research is to understand the performance requirements of electrochromic glazing and its overall contribution to energy saving s and thermal and visual comfort improvement. The performance of the Swiss International School in Dubai was analyzed based on interviews with the design and build team, monitored data and post occupancy evaluation. A systematic process mapping took place to review the performance indicators, simulation tools and team responsibilities during the design, construction and operation stages of the building. The paper identifies the key performance criteria of electrochromic glazing in relation to energy and comfort. Finally, we assess the significance of using electrochromic glazing from a technical point of view and share the learned lessons for architects and facade engineers [less ▲]

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See detailAn Optimal Control Formulation of Pulse-Based Control Using Koopman Operator
Sootla, Aivar; Mauroy, Alexandre; Ernst, Damien ULiege

E-print/Working paper (2018)

In many applications, and in systems/synthetic biology in particular, it is desirable to compute control policies that force the trajectory of a bistable system from one equilibrium (the initial point) to ... [more ▼]

In many applications, and in systems/synthetic biology in particular, it is desirable to compute control policies that force the trajectory of a bistable system from one equilibrium (the initial point) to another equilibrium (the target point), or in other words to solve the switching problem. It was recently shown that, for monotone bistable systems, this problem admits easyto-implement open-loop solutions in terms of temporal pulses (i.e., step functions of fixed length and fixed magnitude). In this paper, we develop this idea further and formulate a problem of convergence to an equilibrium from an arbitrary initial point. We show that this problem can be solved using a static optimization problem in the case of monotone systems. Changing the initial point to an arbitrary state allows to build closed-loop, event-based or open-loop policies for the switching/convergence problems. In our derivations we exploit the Koopman operator, which offers a linear infinite-dimensional representation of an autonomous nonlinear system. One of the main advantages of using the Koopman operator is the powerful computational tools developed for this framework. Besides the presence of numerical solutions, the switching/convergence problem can also serve as a building block for solving more complicated control problems and can potentially be applied to non-monotone systems. We illustrate this argument on the problem of synchronizing cardiac cells by defibrillation. Potentially, our approach can be extended to problems with different parametrizations of control signals since the only fundamental limitation is the finite time application of the control signal. [less ▲]

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See detailDissolved Si export: Impact of increased water fluxes through soil
Ronchi, Bénédicta; Dassargues, Alain ULiege; Batelaan, Okke

in Geoderma (2018), 312

Intense deforestation over large areas is an important component of global models which aim to quantify the transfer of terrestrial siliceous material from the continent to the coast. Hence, there is a ... [more ▼]

Intense deforestation over large areas is an important component of global models which aim to quantify the transfer of terrestrial siliceous material from the continent to the coast. Hence, there is a need for improved understanding of land use impact on Si export. We present a model that simulates the kinetic dissolution of biogenic Si in a forest soil. A kinetic equation was calibrated based on leaching experiments of soil columns at constant water flux. The calibrated equation was then used to simulate the Si export from a forest soil under varying atmospheric conditions and provided realistic Si concentrations in soil water. The same model was used to simulate the impact of reduced evapotranspiration due to deforestation and consequently increased soil water fluxes on the Si export. Results showed that lower amounts of biogenic silicon dissolved and higher Si fluxes were released to the system once water flux increased. The use of the kinetic dissolution equation for biogenic Si improves our understanding and the modelling of the Si release from soils towards the hydrographic system. [less ▲]

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