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See detailContributions to deep reinforcement learning and its applications in smartgrids
François-Lavet, Vincent ULiege

Doctoral thesis (2017)

Reinforcement learning and its extension with deep learning have led to a field of research called deep reinforcement learning. Applications of that research have recently shown the possibility to solve ... [more ▼]

Reinforcement learning and its extension with deep learning have led to a field of research called deep reinforcement learning. Applications of that research have recently shown the possibility to solve complex decision-making tasks that were previously believed extremely difficult for a computer. Yet, deep reinforcement learning requires caution and understanding of its inner mechanisms in order to be applied successfully in the different settings. As an introduction, we provide a general overview of the field of deep reinforcement learning. In the first part of this thesis, we provide an analysis of reinforcement learning in the particular setting of a limited amount of data and in the general context of partial observability. In this setting, we focus on the tradeoff between asymptotic bias (suboptimality with unlimited data) and overfitting (additional suboptimality due to limited data), and theoretically show that while potentially increasing the asymptotic bias, a smaller state representation decreases the risk of overfitting. An original theoretical contribution relies on expressing the quality of a state representation by bounding $L_1$ error terms of the associated belief states. We also discuss and empirically illustrate the role of other parameters to optimize the bias-overfitting tradeoff: the function approximator (in particular deep learning) and the discount factor. In addition, we investigate the specific case of the discount factor in the deep reinforcement learning setting case where additional data can be gathered through learning. In the second part of this thesis, we focus on a smartgrids application that falls in the context of a partially observable problem and where a limited amount of data is available (as studied in the first part of the thesis). We consider the case of microgrids featuring photovoltaic panels (PV) associated with both long-term (hydrogen) and short-term (batteries) storage devices. We propose a novel formalization of the problem of building and operating microgrids interacting with their surrounding environment. In the deterministic assumption, we show how to optimally operate and size microgrids using linear programming techniques. We then show how to use deep reinforcement learning to solve the operation of microgrids under uncertainty where, at every time-step, the uncertainty comes from the lack of knowledge about future electricity consumption and weather dependent PV production. [less ▲]

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See detailContent Working Group Report 2016-2017
Renaville, François ULiege; Varjabedian, Kathy

Conference (2017, September 11)

Report on the activities in 2016-2017 of the Content Working Group (previously Knowledge Base Advisory Board [KBAB]).

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See detailPreliminary Phytochemical Content and Antidiabetic Potential Investigations of Panda oleosa (Pierre) Used in Kisangani Areas
Katemo Muhoya, Frédéric; Kadima Ntokamunda, Justin; Njakarinala Ranarivelo et al

in American Journal of Analytical Chemistry (2017), 8

Panda oleosa Pierre (POP), a tropical plant tree, has been used in traditional medicine in Kisangani city and around to treat various diseases including diabètes and HIV/AIDs. This study aims to evaluate ... [more ▼]

Panda oleosa Pierre (POP), a tropical plant tree, has been used in traditional medicine in Kisangani city and around to treat various diseases including diabètes and HIV/AIDs. This study aims to evaluate the chemical composition of POP extracts while setting up chromatographic fingerprints for their quality control, and the anti-hyperglycemic potential of trunk bark aqueous extracts of POP. Common chemical reactions were used for identification of main secondary metabolic groups. Thin layer chromatography was used to set up several chromatographic fingerprints of water and alcoholic extracts while evaluating chemical composition. Oral glucose tolerance test served to induce hyperglycemia in a rabbit model. The extracts were given as 25 mg/kg, 50 mg/kg, and 100 mg/kg body weight, 30 minutes before loading animals with glucose 4 g/kg. Blood samples were collected at various times: just before extracts (T-30), before (T0) and after glucose load (T30, T60, T120, and T180). Blood glucose levels were measured with One Touch Glucometer. The identification tests revealed the presence of saponins (3.58%), tannins (5%); alkaloids, quinones, flavonoids, and terpenes sterols could not be formerly detected by the reagents used. Interesting chromatographic spots were observed whose behaviors are of catechic tannin proanthocyanes. The extract significantly reduced glucose levels in dose dependent manner as compared to control and glibenclamide reference groups. The average of mean percentage of reduction in glucose level at T120 with the extract 100 mg/kg was close to that of glibenclamide 0.25 mg/kg (49% and 40.2%). These findings back the traditional use of the plant to treat diabetic patients and constitute a foundation for an extensive study to find a new antidiabetic phythomedicine. [less ▲]

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See detailBuckling of steel plates at elevated temperatures: Theory of perfect plates vs finite element analysis
Maraveas, Chrysanthos ULiege; Gernay, Thomas ULiege; Franssen, Jean-Marc ULiege

in Proceedings of CONFAB'17 Conference (2017, September 11)

The local buckling capacity of fire exposed thin-walled steel cross sections is affected by the reduction in strength and stiffness due to elevated temperatures and the amplitude of the initial local ... [more ▼]

The local buckling capacity of fire exposed thin-walled steel cross sections is affected by the reduction in strength and stiffness due to elevated temperatures and the amplitude of the initial local imperfections. Several researchers have proposed design methods to calculate the capacity of the plates (i.e. web and flanges) that compose these steel members at elevated temperatures, but they used different shapes of steel plates (sides ratio a/b) and different amplitudes of local imperfections. This variability in hypotheses happens because there is no clear provision defining the numerical modeling procedure for fire design of steel plates in the codes (European or US). According to the theory of perfect plates, the critical load depends of the shape of the rectangular plate (e.g. the sides ratio a/b) and the corresponding buckling mode (number of half waves), the boundary and the loading conditions. This paper reviews the existing code provisions and compares the existing design models and their assumptions for thin-walled steel cross sections. Elements of the theory of perfect plates are presented. Parametric finite element analyses are then conducted on isolated steel plates at elevated temperatures to investigate the effect of the plate shape (a/b ratio) and imperfections (amplitude and number of half wave lengths). From the analysis, the governing parameter will be estimated (a/b vs imperfections) for simulation of isolated flanges and webs. Finally, recommendations for the numerical modeling of steel plates at elevated temperatures are proposed. [less ▲]

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See detailIdentification et analyse fonctionnelle de nouveaux variants d’épissage du CD46 des bovidés, le (co)-récepteur du virus BVD/MD
Alzamel, Nidal ULiege

Doctoral thesis (2017)

The pestivirus bovine viral diarrhea virus (BVDV) is known to bind to the CD46 molecule, which subsequently promotes entry of the virus. Mapping of the BVD-virion-binding site has shown that two peptides ... [more ▼]

The pestivirus bovine viral diarrhea virus (BVDV) is known to bind to the CD46 molecule, which subsequently promotes entry of the virus. Mapping of the BVD-virion-binding site has shown that two peptides, 66EQIV69 and 82GQVLAL87, located on antiparallel beta sheets in the most distal complement control protein module (CCP1), provide the attachment platform. In the present study, we reveal new CD46-encoding transcripts that are predicted to encode CCP1-containing soluble forms. Further, we show that the serum of most adult cattle contains soluble CD46 (sCD46) and that a recombinant soluble isoform neutralizes BVDV infectivity in an in vitro assay. We have then established an ELISA for determination of plasma sCD46 in a large cohort of animals. Overall, serum sCD46 amounts to 8 ± 18 ng/mL (mean ± SD, n = 543), with a IC [95-105] ranging from 6,4 to 9,8 ng/mL and extreme values between 0 and 178 ng/mL. We found that sCD46 is not detectable in fetal and neonatal sera and that its plasma concentration increases progressively up to adulthood. We also detected high- and low-sCD46 performers and show that this phenotype does not depend of environment. As modern rearing techniques make it possible to disseminate genetically-determined phenotypes very quickly in a population, a large-scale study examining whether high-sCD46 animals provide epidemiological protection against BVDV infection and transmission should be undertaken [less ▲]

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See detailExtracting oscillating components from nonstationary time series: A wavelet-induced method
Deliège, Adrien ULiege; Nicolay, Samuel ULiege

in Physical Review. E : Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics (2017), 96

This paper consists in the description and application of a method called wavelet-induced mode extraction (WIME) in the context of time-frequency analysis. WIME aims to extract the oscillating components ... [more ▼]

This paper consists in the description and application of a method called wavelet-induced mode extraction (WIME) in the context of time-frequency analysis. WIME aims to extract the oscillating components that build amplitude modulated-frequency modulated signals. The essence of this technique relies on the successive extractions of the dominant ridges of wavelet-based time-frequency representations of the signal under consideration. Our tests on simulated examples indicate strong decomposition and reconstruction skills, trouble-free handling of crossing trajectories in the time-frequency plane, sharp performances in frequency detection in the case of mode-mixing problems, and a natural tolerance to noise. These results are compared with those obtained with empirical mode decomposition. We also show that WIME still gives meaningful results with real-life data, namely, the Oceanic Niño Index. [less ▲]

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See detailAn update on ozone profile trends for the period 2000 to 2016
Steinbrecht, Wolfgang; Froidevaux, Lucien; Fuller, Ryan et al

in Atmospheric Chemistry and Physics (2017), 17(17), 10675-10690

Ozone profile trends over the period 2000 to 2016 from several merged satellite ozone data sets and from ground-based data by four techniques at stations of the Network for the Detection of Atmospheric ... [more ▼]

Ozone profile trends over the period 2000 to 2016 from several merged satellite ozone data sets and from ground-based data by four techniques at stations of the Network for the Detection of Atmospheric Composition Change indicate significant ozone increases in the upper stratosphere, between 35 and 48 km altitude (5 and 1 hPa). Near 2 hPa (42 km), ozone has been increasing by about 1.5 % per decade in the tropics (20°S to 20°N), and by 2 to 2.5 % per decade in the 35° to 60° latitude bands of both hemispheres. At levels below 35 km (5 hPa), 2000 to 2016 ozone trends are smaller and not statistically significant. The observed trend profiles are consistent with expectations from chemistry climate model simulations. Using three to four more years of observations and updated data sets, this study confirms positive trends of upper stratospheric ozone already reported, e.g., in the WMO/UNEP Ozone Assessment 2014, or by Harris et al. (2015). The additional years, and the fact that nearly all individual data sets indicate these increases, give enhanced confidence. Nevertheless, a thorough analysis of possible drifts and differences between various data sources is still required, as is a detailed attribution of the observed increases to declining ozone depleting substances and to stratospheric cooling. Ongoing quality observations from multiple independent platforms are key for verifying that recovery of the ozone layer continues as expected. [less ▲]

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See detailBelgique: quelle responsabilité pour le citoyen?
Verjans, Pierre ULiege

Conference given outside the academic context (2017)

Le système politique actuel vit une séparation entre les citoyens et les décideurs. Les citoyens ont les moyens de participer à la décision politique non seulement par le vote mais aussi par l'association ... [more ▼]

Le système politique actuel vit une séparation entre les citoyens et les décideurs. Les citoyens ont les moyens de participer à la décision politique non seulement par le vote mais aussi par l'association, la manifestation, l'expression et désormais par la consultation populaire d'initiative citoyenne. [less ▲]

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See detailDiscours en hommage à François Bovesse
Behrendt, Christian ULiege

Speech/Talk (2017)

Discours d'Hommage prononcé le 11 septembre 2017 au Palais provincial de Namur

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See detailA tiny magic drawing board to track the penetration of magnetic flux in superconductors
Silhanek, Alejandro ULiege

Conference (2017, September 11)

Local polarization of a magnetic layer, a well-known method for storing information, has found its place in numerous applications such as the popular magnetic drawing board toy or the widespread credit ... [more ▼]

Local polarization of a magnetic layer, a well-known method for storing information, has found its place in numerous applications such as the popular magnetic drawing board toy or the widespread credit cards and computer hard drives. Here we experimentally show that a similar principle can be applied for imprinting the trajectory of quantum units of flux (vortices), travelling in a superconducting film (Nb), into a soft magnetic layer of permalloy (Py). In full analogy with the magnetic drawing board, vortices act as tiny magnetic scribers leaving a wake of polarized magnetic media in the Py board. The mutual interaction between superconducting vortices and ferromagnetic domains has been investigated by the magneto-optical imaging technique. For thick Py layers, the stripe magnetic domain pattern guides both the smooth magnetic flux penetration as well as the abrupt vortex avalanches in the Nb film. It is however in thin Py layers without stripe domains where superconducting vortices leave the clearest imprints of locally polarized magnetic moment along their paths. In all cases, we observe that the flux is delayed at the border of the magnetic layer. Our findings open the quest for optimizing magnetic recording of superconducting vortex trajectories. [less ▲]

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See detailNos cours d'eau, une source d'énergie renouvelable passée, présente et future
Erpicum, Sébastien ULiege

Conference given outside the academic context (2017)

L’exploitation de l’énergie hydraulique, verte & renouvelable, a façonné au fil des siècles nombre de nos cours d’eau. Dans le contexte actuel de décentralisation de la production électrique ... [more ▼]

L’exploitation de l’énergie hydraulique, verte & renouvelable, a façonné au fil des siècles nombre de nos cours d’eau. Dans le contexte actuel de décentralisation de la production électrique & d’exploitation des sources non polluantes, l’hydroélectricité trouve un regain d’intérêt qui peut souvent s’accompagner de la remise en valeur d’un patrimoine bâti d’exception. La conférence détaillera ces points & les illustrera par de nombreux exemples. Parmi ceux-ci, la turbine hydroélectrique récemment mise en service au centre de Comblain-au-Pont, avec l’aide de la Région Wallonne, pour assurer l’autonomie énergétique de la Maison communale. [less ▲]

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See detailUsing IPCAPS to identify fine-scale population structure
Chaichoompu, Kridsadakorn ULiege; Fentaw Abegaz, Yazew ULiege; Tongsima, Sissades et al

Poster (2017, September 09)

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See detailWho are “the people” in populist rhetoric? The case of the “Front National” (FN) and the “Freiheitliche Partei Österreichs” (FPÖ)
Debras, François ULiege

Conference (2017, September 09)

In recent years, the “Front National” (FN) in France has claimed to be the “defender of the people” and “guarantor of their interests”. In 2017, the campaign slogan of Marine Le Pen, party leader and ... [more ▼]

In recent years, the “Front National” (FN) in France has claimed to be the “defender of the people” and “guarantor of their interests”. In 2017, the campaign slogan of Marine Le Pen, party leader and candidate in the presidential election, was “in the name of the people”. In Austria, the “Freiheitliche Partei Österreichs” (FPÖ) stood as the “voice of the oppressed majority”. The party is demanding “a direct democracy in order to let the people speak”. These elements lead us to question the notion of “the people”. How should we define “the people”? What reality does it refer to? What are the underlying political and ideological issues? Firstly, to answer this question, I aim to clarify the term “the people” in populist rhetoric. The FN and the FPÖ are often described as “far-right parties”. However, many scholars also refer to them as “populist parties”. These terms clearly need explaining. Secondly, this work will analyse the political discourse of the FN and the FPÖ. The focus will be on the political programmes and oral communication coming from their principal representatives. This analysis is discursive. It isn’t an examination of the work performed by party supporters or members (parliamentary work, action in local authorities, etc.). Apparently, the rhetoric from both parties is structured around two dichotomies: 1) the removal of social boundaries in favour of a people/elite opposition; 2) the affirmation of cultural boundaries in favour of an opposition between natives to a country and foreigners. I will explain why these notions of social and cultural boundaries have a prominent place in rhetoric in line with populist theory. The desire to suppress social boundaries, allows us to identity a first issue: sovereignty. The affirmation of cultural boundaries illustrates a second issue: unity. Finally, a third issue is transmitted through the notion of sovereignty and unity: identity. To conclude, I will return to the classification of the “Front National” and the “Freiheitliche Partei Österreichs” as “right-wing-populist” parties. I will end by answering the question: “who are ‘the people’”? This will explain why populist rhetoric responds to a feeling of unease within society and, more generally, within Western democracies. [less ▲]

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See detailRound table. Quaternary Prevention(P4) or first do not harm.
Jamoulle, Marc ULiege; Widmer, Daniel; La Valle, Ricardo et al

Conference (2017, September 09)

Quaternary prevention (P4), born from a reflection on the doctor-patient relationship, began as an answer of family doctors facing overmedicalization. It aims to protect the patient or population against ... [more ▼]

Quaternary prevention (P4), born from a reflection on the doctor-patient relationship, began as an answer of family doctors facing overmedicalization. It aims to protect the patient or population against the danger of medicine. Harmful effects can appear with preventive activities (example: prostate cancer screening by PSA) as well as by therapeutic interventions (example: disruptive medicine). P4 promoted by the World Organization of Family Doctors (WONCA) is practiced in different ways around the world through the activity of the WONCA Special Interest Group on Quaternary Prevention and Overmedicalisation (P4&O). There are multiple initiatives and backgrounds of P4. All these multiple initiatives that lead to P4 have their origin in denouncing the inadequacies of the Hegemonic Medical Model and the excesses perpetrated in the pursuit of profit. There are many schools of thought that try to solve this situation, such as "Medicines Based on ..." These contributions are valuable but usually point to a single dimension of the problem so they do not change the situation too much. The P4, however, have understood the centrality of the political and economic dimensions and, that is why, P4 has become a movement. P4 has understood that the root causes far exceed the limits of medicine, have understood that the problem includes ethical, political, economic and epistemological aspects of medicine. It is for this reason that the definition of P4 has shifted to the function of foundational idea since the movement that has been generated around this concept has surpassed this initial definition centered in a, yet complex, but still medical vision. P4 has understood that a new model of medicine and a new pact with society is necessary. P4 is a counter-hegemonic movement with predominant development in peripheral countries. This movement includes many other perspectives developed in the central countries but is the only one that has an ideological position that discusses the current paradigm of medicine that legitimates the same causes that give rise to P4, proposing to think a new way of practice the medicine that includes Ethical values, other forms of knowledge and the return to human medicine for humans with place for uncertainty, compassion, the encounter between people and non-commodified. Justice in health care is a central aspect of this new way of conceiving the medicine that we propose. Remember what Rudolf Virchow said in the nineteenth century "Physicians are the natural advocates of the poor and social problems fall largely under their jurisdiction. Medicine is a social science, and politics is nothing more than medicine in large scale". We must reformulate our contract with society and for this we must be very clear that our loyalty must always be with the sick, the poor and those who are weak. For this new contract we must also take into account the magnitude of the power that has been given to us and to live up to such responsibility. In the Rio manifesto (2016) we propose to “Avoid and denounce the naturalization of: hunger, exclusion, manipulation, inequality, violence, racism, exploitation, which harm health more than "diseases"” . There is a better and fairer world, let's fight to get it! More about P4 on www.ph3c.org/p4 [less ▲]

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See detailInscription, iteration, transformation
De Winter, Mélanie ULiege; Slomian, Cynthia ULiege

Conference (2017, September 09)

In “Knowledge in policy”, Freeman and Sturdy propose a phenomenology with the aim of “knowing knowledge” (Freeman & Sturdy, 2014, p. 2). Knowledge can have different forms called “inscribed”, “embodied” ... [more ▼]

In “Knowledge in policy”, Freeman and Sturdy propose a phenomenology with the aim of “knowing knowledge” (Freeman & Sturdy, 2014, p. 2). Knowledge can have different forms called “inscribed”, “embodied” and “enacted”. This framework is presented as a way to categorize and describe the form, the circulation and the transformation of knowledge in policymaking. In this paper, we intend to focus on inscribed knowledge, and particularly on documents conceived as essential artefacts of public policies (Freeman & Maybin, 2011). Freeman and Sturdy defined inscribed knowledge as “written down in texts, or represented in pictures and diagrams; or it may be incorporated into instruments, tools and machines, among other things”(Freeman & Sturdy, 2014, p. 10). This form of knowledge is particularly “stable”, “easily reproducible” and “highly mobile” so “it can be communicated or made available to many different individuals separated in time and/or space”(Freeman & Sturdy, 2014, p. 10). This statement draws from works in sociology of science and technology. These works, especially Latour’s (1987) studies of the laboratory work and Law's (1986) analysis of control at distance particularly emphasize the power of inscriptions in constraining social action over time and space. Through the analysis of the implementation of two policy plans in the Belgian healthcare sector, we question and put the role of inscriptions in perspective with moments of enactment, by focusing on meetings. We intend to show that some documents are crucial at particular moments and lose value at other moments. In the same vein, we also aim to show the importance of iteration, moments, duration, and rhythms in public action. By doing so, we show how the public policy itself is transformed through time, documents and meetings. We address this issue by drawing on two PhD researches focusing on the devising and implementation of the policy plans mentioned above. By relying on interviews, observations and document analysis, we describe the policy strategies inscribed in documents as well as key moments of both documents’ trajectories. In so doing, we emphasise that documents and meetings articulate with each other in an iterative process that in turn transforms the public policies themselves. [less ▲]

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See detailTowards a web-based platform for plotting, visualizing and enriching diachronic semantic maps: With a case study on the Greek and Egyptian temporal semantic field
Georgakopoulos, Athanasios ULiege; Polis, Stéphane ULiege

Conference (2017, September 09)

Semantic maps aim at detecting cross-linguistic regularities and recurrent patterns in semantic structure (Haspelmath 2003). This method was initially applied to the grammatical domain, mostly in a ... [more ▼]

Semantic maps aim at detecting cross-linguistic regularities and recurrent patterns in semantic structure (Haspelmath 2003). This method was initially applied to the grammatical domain, mostly in a synchronic perspective (with some exceptions, see, e.g., van der Auwera & Plungian 1998). Recent research, however, has drawn attention to the lexical domain, showing that the model can also include lexical semantics (see, e.g., François 2008). Intimately related to the semantic map method has been the issue of finding appropriate ways of creating those maps and of capturing visually the semantic regularities. Up until recently, the maps were plotted and drawn manually. However, Regier et al. (2013) showed that a good approximation algorithm exists for inferring semantic maps based on polysemy data. Elaborating on their method, this paper aims to demonstrate that information about the directionality and the weight of the edges can be automatically added, thereby providing valuable information regarding the paths of semantic extensions and their frequency. In order to illustrate the method, we take the example of the semantic extension of time-related lexemes (e.g. TIME, HOUR, SEASON, DAY) in Ancient Greek (8th – 1st c. BC) and Ancient Egyptian – Coptic (26th c. BC – 10th c. AD). Both languages give access to significant diachronic material, allowing us to trace long term processes of semantic change. The results of our diachronic investigations are then checked against databases giving information on synchronic polysemies (e.g., List et al. 2014). In doing so, we also assess the adequacy of the use of polysemy as a tool to investigate semantic change. [less ▲]

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See detailExploring insulin resistance in migraine: a population-based study
Streel, Sylvie ULiege; Donneau, Anne-Françoise ULiege; Schoenen, Jean ULiege et al

Poster (2017, September 09)

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See detailA method for hybrid fire testing: Development, implementation and numerical application
Sauca, Ana ULiege; Mergny, Elke ULiege; Gernay, Thomas ULiege et al

in Gillie, Martin; Wang, Yong (Eds.) Proceedings of ASFE 2017 Conference (2017, September 08)

Hybrid Fire Testing (HFT) is a technique that allows assessing experimentally the fire performance of a structural element under real boundary conditions that capture the effect of the surrounding ... [more ▼]

Hybrid Fire Testing (HFT) is a technique that allows assessing experimentally the fire performance of a structural element under real boundary conditions that capture the effect of the surrounding structure. To enable HFT, there is a need for a method that is unconditionally stable, ensures equilibrium and compatibility at the interface and captures the global behaviour of the analysed structure. A few attempts at conducting HFT have been described in the literature, but it can be shown, based on the analytical study of a simple one degree-of-freedom elastic system, that the considered method was fundamentally unstable in certain configurations which depend on the relative stiffness between the two substructures, but which cannot be easily predicted in advance. In this paper, a new method is introduced to overcome the stability problem and it is shown through analytical developments and applicative examples that the stability of the new method does not depend on the stiffness ratio between the two substructures. The new method is applied in a virtual hybrid test on a 2D reinforced concrete beam part of a moment resisting frame, showing that stability, equilibrium and compatibility are ensured on the considered multiple degree-of-freedom system. Besides, the virtual HFT succeeds in reproducing the global behaviour of the analysed structure. The method development and implementation in a virtual (numerical) setting is described, the next step being its implementation in a real (laboratory) hybrid test. [less ▲]

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