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See detailKarstic Systems in Eastern Belgium: Remouchamps and Noû Bleû
Peeters, Alexandre ULiege; Ek, Camille ULiege

in Demoulin, Alain (Ed.) Landscapes and Landforms of Belgium and Luxembourg (2018)

Belgium is characterised by a wide variety of rocks, including carbonate formations, which are significantly represented in eastern Belgium. Among those formations, Devonian and Carboniferous carbonates ... [more ▼]

Belgium is characterised by a wide variety of rocks, including carbonate formations, which are significantly represented in eastern Belgium. Among those formations, Devonian and Carboniferous carbonates display the most developed karstic features, as illustrated by the two cave systems presented in this chapter. Although both systems are water caves, they differ in many ways. The Remouchamps Cave, developed in the Upper Devonian limestones, is a touristic cave, while the Noû Bleû Cave, developed in the Carboniferous carbonates, is a brand new discovery still under exploration. The two systems are of scientific interest and contain many deposits (speleothems and detrital sediments) providing records of past environmental changes and paleoclimates. Beside the Quaternary dynamics, the present-day dynamics can be highlighted within the karstic basins that encompass the two cave systems. The generation or reactivation of sinkholes and swallow holes is often favoured or triggered by human activity. Furthermore, the two basins offer several good examples of human interaction with karst environments, not only in terms of karstic constraints for humans but also as a resource that must be preserved. [less ▲]

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See detailA fully coupled hydro-mechanical model for the modeling of coalbed methane recovery
Bertrand, François ULiege; Cerfontaine, Benjamin ULiege; Collin, Frédéric ULiege

in Natural Gas science and Engineering (2018)

Most coal seams hold important quantities of methane which is recognized as a valuable energy resource. Coal reservoir is considered not conventional because methane is held adsorbed on the coal surface ... [more ▼]

Most coal seams hold important quantities of methane which is recognized as a valuable energy resource. Coal reservoir is considered not conventional because methane is held adsorbed on the coal surface. Coal is naturally fractured, it is a dual-porosity system made of matrix blocks and cleats (i.e fractures). In general, cleats are initially water saturated with the hydrostatic pressure maintaining the gas adsorbed in the coal matrix. Production of coalbed methane (CBM) first requires the mobilization of water in the cleats to reduce the reservoir pressure. Changes of coal properties during methane production are a critical issue in coalbed methane recovery. Indeed, any change of the cleat network will likely translate into modifications of the reservoir permeability. This work consists in the formulation of a consistent hydro-mechanical model for the CBM production modeling. Due to the particular structure of coal, the model is based on a dual-continuum approach to enrich the macroscale with microscale considerations. Shape factors are employed to take into account the geometry of the matrix blocks in the mass exchange between matrix and fractures. The hydro-mechanical model is fully coupled. For example, it captures the sorption-induced volumetric strain or the dependence of permeability on fracture aperture, which evolves with the stress state. The model is implemented in the finite element code Lagamine and is used for the modeling of one production well. A synthetic reservoir and then a real production case are considered. To date, attention has focused on a series of parametric analyses that can highlight the influence of the production scenario or key parameters related to the reservoir. [less ▲]

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See detailInfluence of different hydrocolloids on dough thermo-mechanical properties and in vitro starch digestibility of gluten-free steamed bread based on potato flour
Liu, Xingli ULiege; Mu, Taihua; Sun, Hongnan et al

in Food Chemistry (2018), 239

The effects of hydrocolloids (Hydroxypropylmethylcellulose (HPMC), Carboxymethylcellulose (CMC), Xanthan gum (XG), and Apple pectin (AP)) at different concentrations on dough thermo-mechanical properties ... [more ▼]

The effects of hydrocolloids (Hydroxypropylmethylcellulose (HPMC), Carboxymethylcellulose (CMC), Xanthan gum (XG), and Apple pectin (AP)) at different concentrations on dough thermo-mechanical properties and in vitro starch digestibility of gluten-free potato steamed bread were investigated. Results showed that hydrocolloids addition significantly increased the gelatinization temperature (from 52.0 to 64.2 °C) and water absorption (from 56.22 to 66.50 %) of potato dough. Moreover, hydrocolloids may be interacted with protein and starch, the density of potato protein bands was decreased by hydrocolloids addition, the reason might be that higher molecular weight complexes might be formed between proteins-hydrocolloids or proteins-proteins, thus change the protein solubility. Furthermore, steamed breads with hydrocolloids presented higher specific volume and lower hardness, and the rapidly digestible starch and estimated glycemic index were significantly decreased from 45.51 to 20.64, from 69.54 to 55.17, respectively. In conclusion, HPMC and XG could be used as improvers in the gluten-free potato steamed bread. [less ▲]

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See detailDiscovering Routers in Load-balanced Paths
Grailet, Jean-François ULiege; Donnet, Benoît ULiege

in 13th International Conference on emerging Networking EXperiments and Technologies Student Workshop (2017, December 12)

Usually, a set of Traceroute measurements collected for a large amount of target IPs contain one or several route hops at which the IP interfaces vary from one measurement to another. These variations ... [more ▼]

Usually, a set of Traceroute measurements collected for a large amount of target IPs contain one or several route hops at which the IP interfaces vary from one measurement to another. These variations occur even if several measurements share the same length and the same last hops. This is likely a consequence of load balancing, a traffic engineering policy which aims at sharing the load to ensure quality of service. In this paper, we consider the problem of conducting alias resolution on IP interfaces discovered via Traceroute and which are involved in load balancing. By conducting alias resolution in such a context, we want to verify if the IP interfaces involved in load balancing belong to unique routers, and more broadly, how relevant is alias resolution in this context. To do so, we use a slightly edited version of TreeNET, a topology discovery tool which relies on a tree-like structure based on Traceroute measurements to map a target domain. The upgraded TreeNET along the measurements described in this paper are both freely available online. [less ▲]

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See detailAn Observation-Based Middlebox Policy Taxonomy
Edeline, Korian ULiege; Donnet, Benoît ULiege

in 13th International Conference on emerging Networking EXperiments and Technologies Student Workshop (2017, December 12)

Recent years have seen the rise of middleboxes, such as NATs, firewalls, or TCP accelerators. Those middleboxes play an important role in today's Internet, including enterprise networks and cellular ... [more ▼]

Recent years have seen the rise of middleboxes, such as NATs, firewalls, or TCP accelerators. Those middleboxes play an important role in today's Internet, including enterprise networks and cellular networks. However, despite their undisputable success in modern network architecture, their actual impact on packets, traffic, and network performance is not that much understood. In this paper, we propose a path impairment oriented middlebox classification that aims at categorizing the initial purpose of a middlebox policy as well as its potential complications. [less ▲]

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See detailCoding of papers submitted to the 14th Congresso Brasileiro de Medicina de Família e Comunidade
Knupp, Daniel Augusto; Rebolho, Ricardo; Jamoulle, Marc ULiege et al

Conference (2017, December 05)

Introduction: The intention of codifying the 14th CBMFC's work with the use of 3CGP (Core Concept Classification in General Practice Family Medicine) appeared during the 21st WONCA World Conference of ... [more ▼]

Introduction: The intention of codifying the 14th CBMFC's work with the use of 3CGP (Core Concept Classification in General Practice Family Medicine) appeared during the 21st WONCA World Conference of Family Physicians, when members of the organizing committee of the 14th CBMFC were able to participate in an activity given by Dr Marc Jamoulle on the subject and realized how important it could be to use 3CGP. It consists of using the International Classification of Primary Care (CIAP-2) and the Q-Codes to classify the contents of abstracts submitted to the congress. CBMFCs are large events, which usually receive a substantial number of abstracts. The experience of using 3CGP in an event of this magnitude can have a great impact for the development of the specialty in the country, besides having a pioneering character, contributing for 3CGP to become an international standard in the congresses of family and community medicine. Objectives: Assist the author in the choice of theme; Teaching how to index; Contribute to updating the Q Codes; Manage the congress; Contribute in the management of knowledge in family and community medicine. Method: This is an action research experiment that will consist of the coding of all abstracts submitted to the 14th CBMFC with the use of 3CGP. Authors will be introduced to the classification system by means of an introductory text and should submit their work on the event site using a system that already allows them to perform the encoding of the abstract. The data obtained in this process will be evaluated by members of the organizing committee of the 14th CBMFC, who will be in charge of synthesizing it. [less ▲]

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See detailThe LBTI Fizeau imager - I. Fundamental gain in high-contrast imaging
Patru, F.; Esposito, S.; Puglisi, A. et al

in Monthly Notices of the Royal Astronomical Society (2017), 472

We show by numerical simulations a fundamental gain in contrast when combining coherently monochromatic light from two adaptive optics (AO) telescopes instead of using a single stand-alone AO telescope ... [more ▼]

We show by numerical simulations a fundamental gain in contrast when combining coherently monochromatic light from two adaptive optics (AO) telescopes instead of using a single stand-alone AO telescope, assuming efficient control and acquisition systems at high speed. A contrast gain map is defined as the normalized point spread functions (PSFs) ratio of a single Large Binocular Telescope (LBT) aperture over the dual Large Binocular Telescope Interferometer (LBTI) aperture in Fizeau mode. The global gain averaged across the AO-corrected field of view is improved by a factor of 2 in contrast in long exposures and by a factor of 10 in contrast in short exposures (i.e. in exposures, respectively, longer or shorter than the coherence time). The fringed speckle halo in short exposures contains not only high-angular resolution information, as stated by speckle imaging and speckle interferometry, but also high-contrast imaging information. A high-gain zone is further produced in the valleys of the PSF formed by the dark Airy rings and/or the dark fringes. Earth rotation allows us to exploit various areas in the contrast gain map. A huge-contrast gain in narrow zones can be achieved when both a dark fringe and a dark ring overlap on to an exoplanet. Compared to a single 8-m LBT aperture, the 23-m LBTI Fizeau imager can provide a gain in sensitivity (by a factor of 4), a gain in angular resolution (by a factor of 3) and, as well, a gain in raw contrast (by a factor of 2-1000 varying over the AO-corrected field of view). [less ▲]

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See detailAlbertina, más viva que muerta
Dubois, Jacques ULiege; Mogollon Zapata, Juan Manuel ULiege

in Revista Linguística y Literatura (2017), 72(38), 272-287

El siguiente texto hace parte de un reciente libro que Jacques Dubois tituló Figuras del deseo. Por una crítica amorosa (Les Impressions Nouvelles, 2011). A Dubois lo conocemos hoy en día como fundador ... [more ▼]

El siguiente texto hace parte de un reciente libro que Jacques Dubois tituló Figuras del deseo. Por una crítica amorosa (Les Impressions Nouvelles, 2011). A Dubois lo conocemos hoy en día como fundador del famoso Grupo μ, al que le debemos la Retórica general (1970), como autor en 1978 de una obra fundamental para la sociología de la literatura, La institución de la literatura, y como especialista de Georges Simenon y de la literatura francesa de los siglos xix y xx. En su último libro, el científico riguroso cede la palabra al lector ferviente, crítico-amoroso desconcertante y lleno de imaginación, pero que no deja de sorprendernos con una nueva propuesta metodológica que bien podría calificarse como «una lectura activa del deseo». ¿En qué consiste esta «crítica amorosa»? ¿Cómo definirla? Se trata, ante todo, de una lectura en la que el crítico, animado por su deseo, rehúsa desempeñar un rol pasivo para intervenir así en la narración que le da vida a los personajes, dejando al mismo tiempo que estos se inmiscuyan en el relato de su propia vida. ¡Y su intervención resulta reveladora! Habitado por el mundo de la novela, el crítico «activo e imaginativo» que es Dubois termina por colaborar con el novelista, o por lo menos con el narrador, para desentrañar los posibles significados del universo narrativo, pero también para encontrar allí posibles fisuras en las que pueda deslizar su potente acción creadora, abriendo así «la perspectiva de una novela que pudo haber sido otra cosa de lo que es» (Dubois, 2011, p. 8). Nos encontramos pues frente a una «lectura activa» que se erige entre las exigencias de significación impuestas por el texto y el deseo que este genera de prolongarlo, de transformarlo. Los vectores de dicho deseo serán los personajes mismos, que el crítico-amoroso acompaña y hace brillar en todas sus potencialidades significativas, dotándolos de una vida segunda. De ahí que, como lo señala el mismo Dubois, «la lectura activa, en su versión amorosa, adquiera derechos sobre la ficción» (p. 10) sin que esto signifique por lo tanto que se traicione el texto, pues se trata más bien de hacerlo explotar. Y es en esta explosión que surge la pregunta, latente en la nueva propuesta que nos hace Dubois, por el acto de la lectura: «¿Qué significa amar un personaje?» ¿Cómo se desarrolla una lectura crítica y creadora? La respuesta nos llevará a lo que podríamos llamar desde ya una lectura social del deseo en la que se opera «un deslizamiento progresivo del placer y de lo sexual hacia lo social», como lo muestra el autor en el siguiente capítulo. [less ▲]

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See detailNon-renewable and intermittent renewable energy sources: friends and foes?
Jacqmin, Julien ULiege; Barranes, Edmond; Poudou, Jean-christophe

in Energy Policy (2017), 111

This paper studies the links between non-renewable and intermittent renewable energy sources in the production of electricity. Using U.S. state-level data from 1998 to 2015, we find that the relationship ... [more ▼]

This paper studies the links between non-renewable and intermittent renewable energy sources in the production of electricity. Using U.S. state-level data from 1998 to 2015, we find that the relationship between the price of natural gas and investments in solar and wind capacity is non-linear and can be represented by an inverted U-shape. Hence, for relatively low natural gas prices, the two modes of production are substitutes. After a price threshold is reached, the two are complementary. A theoretical explanation argues that this stylized fact is the result of a trade-off between two characteristics of these modes of production: the high degree of flexibility of electricity production using natural gas as an input and the low marginal cost of renewable energy sources. [less ▲]

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See detailSepsis prediction in critically ill patients by platelet activation markers on ICU admission: a prospective pilot study
LAYIOS, Nathalie ULiege; Delierneux, Céline ULiege; Hego, Alexandre ULiege et al

in Intensive Care Medicine Experimental (2017), 5(1), 32

Background: Platelets have been involved in both surveillance and host defense against severe infection. To date, whether platelet phenotype or other hemostasis components could be associated with ... [more ▼]

Background: Platelets have been involved in both surveillance and host defense against severe infection. To date, whether platelet phenotype or other hemostasis components could be associated with predisposition to sepsis in critical illness remains unknown. The aim of this work was to identify platelet markers that could predict sepsis occurrence in critically ill injured patients. Results: This single-center, prospective, observational, 7-month study was based on a cohort of 99 non-infected adult patients admitted to ICUs for elective cardiac surgery, trauma, acute brain injury and post-operative prolonged ventilation and followed up during ICU stay. Clinical characteristics and severity score (SOFA) were recorded on admission. Platelet activation markers, including fibrinogen binding to platelets, platelet membrane P-selectin expression, plasma soluble CD40L, and platelet-leukocytes aggregates were assayed by flow cytometry at admission and 48h later, and also at the time of sepsis diagnosis (Sepsis-3 criteria) and 7 days later for sepsis patients. Hospitalization data and outcomes were also recorded. Of the 99 patients, 19 developed sepsis after a median time of 5 days. SOFA at admission was higher; their levels of fibrinogen binding to platelets (platelet-Fg) and of D-dimers were significantly increased compared to the other patients. Levels 48h after ICU admission were no longer significant. Platelet-Fg % was an independent predictor of sepsis (P = 0.030). By ROC curve analysis cutoff points for SOFA (AUC=0.85) and Platelet-Fg (AUC=0.75) were 8 and 50%, respectively. The prior risk of sepsis (19%) increased to 50% when SOFA was above 8, to 46% when Platelet-Fg was above 50%, and to 87% when both SOFA and Platelet-Fg were above their cutoff values. By contrast, when the two parameters were below their cutoffs, the risk of sepsis was negligible (3.8%). Patients with sepsis had longer ICU and hospital stays and higher death rate. Conclusion: In addition to SOFA, platelet-bound fibrinogen levels assayed by flow cytometry within 24h of ICU admission help identifying critically ill patients at risk of developing sepsis. [less ▲]

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See detailA Methodology to Determine the Potential of Urban Densification through Roof Stacking
Amer, Mohamed ULiege; Mustafa, Ahmed; Teller, Jacques ULiege et al

in Sustainable Cities and Society (2017), 35

Facing the need to accommodate a growing number of inhabitants in major European cities, this research aimed to establish a methodology that facilitates decision making on urban densification through roof ... [more ▼]

Facing the need to accommodate a growing number of inhabitants in major European cities, this research aimed to establish a methodology that facilitates decision making on urban densification through roof stacking. The methodology adopts a systematic approach on three consecutive levels: urban, engineering, and social. Multiple criteria are identified to assess and map the roof stacking potential in terms of location and number of added floors. The Brussels Capital Region was chosen as a case study to experiment with the developed workflow chart and validate the proposed approach, using ArcGIS software, by creating a map of the urban densification potential through roof stacking of Brussels at the city scale. The results show a realistic potential of accommodating 30% of the expected population increase in Brussels by the year 2040 using only roof stacking, provided that the current urban regulations are respected. In addition, a theoretical potential to accommodate more than the expected population increase by the same year is proposed provided that urban planning regulations are relaxed in relation to the height of buildings. Further applications to other cities in Europe would help create additional opportunities to develop an automated tool for estimating such potentials on a wider scope. [less ▲]

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See detailPratiques d’évaluation des acquis, ancienneté et attitudes face à l’évaluation
Romainville, Marc; Detroz, Pascal ULiege; Auquière, Amélie ULiege et al

Conference (2017, November 16)

La présente communication est issue d’une recherche plus globale visant à identifier et à mieux comprendre les pratiques d’évaluation des acquis des étudiants auxquelles recourent les enseignants de ... [more ▼]

La présente communication est issue d’une recherche plus globale visant à identifier et à mieux comprendre les pratiques d’évaluation des acquis des étudiants auxquelles recourent les enseignants de l’enseignement supérieur et en particulier les facteurs personnels (ancienneté, attitudes vis-à-vis de l’évaluation…) et contextuels (année d’étude, taille du groupe, disciplines…) qui influencent ces pratiques. Les données ont été recueillies en 2016, d’une part, via une enquête en ligne (élaborée à l’aide du logiciel d’enquêtes Qualtrics) auprès d’enseignants de l’enseignement supérieur belge francophone que ce soit à l’Université ou en Hautes écoles (2292 réponses) et, d’autre part, via 37 entretiens semi-structurés individuels réalisés auprès d’un échantillon de ces mêmes enseignants dans des filières d’études contrastées. Les résultats présentés dans le cadre de cette communication ont trait à l’impact de deux variables personnelles : l’ancienneté des enseignants et leurs attitudes vis-à-vis de l’évaluation. Autrement dit, on cherchera à savoir si l’ancienneté et le développement professionnel qui l’accompagne traditionnellement ont des incidences sur le type de pratiques d’évaluation des acquis des enseignants. En particulier, recourent-ils à des outils de plus en plus diversifiés ou ont-ils tendance à se spécialiser dans l’un ou l’autre ? Et si oui, pourquoi ? Accentuent-ils par ailleurs le recours à l’évaluation continue par rapport au poids du contrôle terminal ? On cherchera ensuite à comprendre comment les pratiques se reconfigurent en fonction des attitudes des enseignants vis-à-vis de l’évaluation et en particulier vis-à-vis de sa fonction et de son rapport à l’apprentissage : dans quel sens une conception davantage intégrative de l’évaluation colore-t-elle les pratiques déclarées d’évaluation ? [less ▲]

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See detailOverview and future challenges of nearly Zero Energy Buildings (nZEB) design in Southern Europe
Attia, Shady ULiege; Polyvios, Eleftheriou; Xeni, Flouris et al

in Energy and Buildings (2017), 155

In times of great transition of the European construction sector to energy efficient and nearly zero energy buildings (nZEB), a market observation containing qualitative and quantitative indications ... [more ▼]

In times of great transition of the European construction sector to energy efficient and nearly zero energy buildings (nZEB), a market observation containing qualitative and quantitative indications should help to fill out some of the current gaps concerning the EU 2020 carbon targets. Next to the economic challenges, there are equally important factors that hinder renovating the existing residential building stock and adding newly constructed high performance buildings. Under these circumstances this paper summarises the findings of a cross-comparative study of the societal and technical barriers of nZEB implementation in 7 Southern European countries. The study analyses the present situation and provides an overview on future prospects for nZEB in Southern Europe. The result presents an overview of challenges and provides recommendations based on available empirical evidence to further lower those barriers in the European construction sector. The paper finds that the most Southern European countries are poorly prepared for nZEB implementation and especially to the challenge/opportunity of retrofitting existing buildings. Creating a common approach to further develop nZEB targets, concepts and definitions in synergy with the climatic, societal and technical state of progress in Southern Europe is essential. The paper provides recommendations for actions to shift the identified gaps into opportunities for future development of climate adaptive high performance buildings. [less ▲]

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See detailX-ray study of bow shocks in runaway stars
De Becker, Michaël ULiege; del Valle, M.V.; Romero, G.E. et al

in Monthly Notices of the Royal Astronomical Society (2017), 471(4), 4452-4464

Massive runaway stars produce bow shocks through the interaction of their winds with the interstellar medium, with the prospect for particle acceleration by the shocks. These objects are consequently ... [more ▼]

Massive runaway stars produce bow shocks through the interaction of their winds with the interstellar medium, with the prospect for particle acceleration by the shocks. These objects are consequently candidates for non-thermal emission. Our aim is to investigate the X-ray emission from these sources. We observed with XMM-Newton a sample of 5 bow shock runaways, which constitutes a significant improvement of the sample of bow shock runaways studied in X-rays so far. A careful analysis of the data did not reveal any X-ray emission related to the bow shocks. However, X-ray emission from the stars is detected, in agreement with the expected thermal emission from stellar winds. On the basis of background measurements we derive conservative upper limits between 0.3 and 10 keV on the bow shocks emission. Using a simple radiation model, these limits together with radio upper limits allow us to constrain some of the main physical quantities involved in the non-thermal emission processes, such as the magnetic field strength and the amount of incident infrared photons. The reasons likely responsible for the non-detection of non-thermal radiation are discussed. Finally, using energy budget arguments, we investigate the detectability of inverse Compton X-rays in a more extended sample of catalogued runaway star bow shocks. From our analysis we conclude that a clear identification of non-thermal X-rays from massive runaway bow shocks requires one order of magnitude (or higher) sensitivity improvement with respect to present observatories. [less ▲]

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See detailImproving fungal disease forecasts in winter wheat: A critical role of intra-day variations of meteorological conditions in the development of Septoria leaf blotch
El Jarroudi, Moussa ULiege; kOUADIO, Louis; EL JARROUDI, Mustapha et al

in Field Crops Research (2017), 213

Meteorological conditions are important factors in the development of fungal diseases in winter wheat and are the main inputs of the decision support systems used to forecast disease and thus determine ... [more ▼]

Meteorological conditions are important factors in the development of fungal diseases in winter wheat and are the main inputs of the decision support systems used to forecast disease and thus determine timing for efficacious fungicide application. This study uses the Fourier transform method (FTM) to characterize temporal patterns of meteorological conditions between two neighbouring experimental sites used in a regional fungal disease monitoring and forecasting experiment in Luxembourg. Three meteorological variables (air temperature, relative humidity, and precipitation) were included, all conducive to infection of wheat by Zymoseptoria tritici cause of Septoria leaf blotch (STB) in winter wheat, from 2006 to 2009. The intraday, diurnal, dekadal and intra-seasonal variations of the meteorological variables were assessed using FTM, and the impact of existing contrasts between sites on the development of STB was analyzed. Although STB severities varied between sites and years (P ≤ 0.0003), the results indicated that the two sites presented the same patterns of meteorological conditions when compared at larger temporal scales (diurnal to intra-seasonal scales, with time periods >11 h). However, the intraday variations of all the variables were well discriminated between the sites and were highly correlated to STB severities. Our findings highlight and confirm the importance of intraday meteorological variation in the development of STB in winter wheat fields. Furthermore, the FTM approach has potential for identifying microclimatic conditions prevailing at given sites and could help in improving the prediction of disease forecast models used in regional warning systems. [less ▲]

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See detailTwenty-year tracking of lighting savings and power density in the residential sector
Attia, Shady ULiege; Hamdy, Mohamed; Ezzeldin, Sherif

in Energy and Buildings (2017), 154

Lighting energy consumption represents a significant percentage of total energy consumption in residential building sector. During the last 20 years, advanced energy-efficient lighting fixtures have been ... [more ▼]

Lighting energy consumption represents a significant percentage of total energy consumption in residential building sector. During the last 20 years, advanced energy-efficient lighting fixtures have been introduced worldwide to conserve the energy consumption in residences. In the Middle East and North Africa (MENA) region, very few studies have been conducted to evaluate the association between the introduced lighting fixtures and the resulted energy savings using valid measurements and verification techniques. This study evaluates the techno-economic impact of replacing new energy efficient lighting in residences in Egypt (a representative MENA region country). A quantitative analysis is applied by tracking the utility bills of 150 residential apartments in Cairo. The average measured power consumption before (1993-1998) and after (2009-2014) installation energy efficient lighting fixtures is analyzed. A building performance simulation model is developed to back the findings. The findings indicate a significant disparity between the estimated savings based on simulation and the real measured savings due to penetration, rebound effect and low quality lamps. Moreover, the findings present an example of quantified benefits of energy efficient lighting, which is very important to inform the decision making of public policy makers, investors and building occupants. [less ▲]

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See detailEvaluation of adaptive facades: The case study of Al Bahr Towers in the UAE
Attia, Shady ULiege

in Shaping Qatar’s Sustainable Built Environment (2017), 2(6), 1-13

The assessment of adaptive facades presents a barrier as there is no established assessment technique. Many of the available facade performance evaluation systems or frameworks have limited applicability ... [more ▼]

The assessment of adaptive facades presents a barrier as there is no established assessment technique. Many of the available facade performance evaluation systems or frameworks have limited applicability for such advanced building facades. The complexity of adaptive or dynamic facades’ evaluation is related to the performance evaluation of facade elements, systems, and overall building performance coupled with occupant behavior and occupant satisfaction. In this context, this paper presents a case study of an adaptive sunscreen facade and evaluation of its performance and occupant behavior. The evaluation mainly focuses on pre- and post-construction phases of adaptive facades: the design assist phase (including the durability test, visual mockup, onsite mashrabiya mounting, and weather stripping), the commissioning phase (field verification and performance testing), and the monitoring phase. The selected project is a 150-meter-high twin tower that stands with a honeycombinspired structure and automated dynamic solar screen that responds to the sun’s movement. These solar screens respond dynamically and automatically to the angle of the sun, which improves the control over energy consumption, solar radiation, and glare with the ability to allow natural light into the building. This paper is part of the research activities of working group 3 of the European COST Action 1403 on “Adaptive Facades”. Different methods were used for evaluation and these include the following: interviews with the architect, facade engineer, technical control specialist and occupants, reviews of standards and codes, review of energy models, and a systematic design process mapping. A documentation of the case study describing the post-construction occupant comfort and facade operation was prepared. This paper’s audience comprises mainly project managers, architects, and building facade engineers together with facility managers who are concerned with the process of design, construction, and operation of adaptive sunscreens facades. The outcome of this study identifies quantifiable performance indicators and effective strategies for the design and performance evaluation of optimal adaptive facades. [less ▲]

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See detailMeasuring brain synaptic vesicle protein 2A with positron emission tomography and [18F]UCB-H.
Bahri, Mohamed Ali ULiege; Plenevaux, Alain ULiege; Aerts, Joël ULiege et al

in Alzheimer’s & Dementia: Translational Research & Clinical Interventions (2017), 4(4), 481-486

Introduction: Brain distribution of synaptic vesicle protein 2Awas measured with fluorine-18 UCBH ([18F]UCB-H) and positron emission tomography (PET). Methods: Images of synaptic density were acquired in ... [more ▼]

Introduction: Brain distribution of synaptic vesicle protein 2Awas measured with fluorine-18 UCBH ([18F]UCB-H) and positron emission tomography (PET). Methods: Images of synaptic density were acquired in healthy volunteers (two young participants and two seniors). Input function was measured by arterial blood sampling (arterial input function) and derived from PET images using carotid activity (image-derived input function). Logan graphical analysis was used to estimate regional synaptic vesicle protein 2A distribution volume. Results: [18F]UCB-H uptake was ubiquitous in cortical and subcortical gray matter. Arterial input function and image-derived input function provided regional distribution volume with a high linear relationship. Discussion: The cerebral distribution of [18F]UCB-H is similar to that recently observed with carbon-11 UCB-J ([11C]UCB-J). An accurate [18F]UCB-H quantification can be performed without invasive arterial blood sampling when no suitable reference region is available, using dynamic PET carotid activity. Brain synaptic density can be studied in vivo in normal and pathological aging. [less ▲]

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See detailImproving QoE Prediction in Mobile Video through Machine Learning
Casas, Pedro; Wassermann, Sarah ULiege

in Proc. 8th International Conference on Network of the Future (2017, November)

Despite the massive adoption of HTTP adaptive streaming technology, buffering is still the most harmful event for QoE in video streaming. Previous studies have shown that buffering is not only detrimental ... [more ▼]

Despite the massive adoption of HTTP adaptive streaming technology, buffering is still the most harmful event for QoE in video streaming. Previous studies have shown that buffering is not only detrimental for the overall user experience, but is also highly correlated to viewer engagement. The occurrence of buffering is particularly critical in cellular networks and mobile video deployments, as network conditions are less stable and network resources more limited. In this context, monitoring and properly predicting the QoE of video streaming services becomes paramount to cellular network operators, who need to offer high quality levels to reduce the risks of customers churning for quality dissatisfaction. In this paper, we present a novel approach to multi-dimensional QoE prediction in mobile video using machine learning models. Contrary to previous models for QoE prediction in video streaming, which are generally uni- or low-dimensional and model the impact of single video descriptors independently, we use a high-dimensional input space to model the impact of buffering and initial delay on QoE.We train and test the proposed models on a publicly available mobile video dataset, generated from subjective QoE tests with real viewers. Besides improving prediction performance, the proposed models show that there is a clear influence of other buffering pattern descriptors generally neglected in previous models - in particular those linked to the occurrence of the last stalling event, shedding light on new KPIs to monitor for better QoE assessment in video streaming. [less ▲]

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See detailThrough the Wormhole: Tracking Invisible MPLS Tunnels
Vanaubel, Yves ULiege; Mérindol, Pascal; Pansiot, Jean-Jacques et al

in ACM Internet Measurement Conference (2017, November)

For years, Internet topology research has been conducted through active measurement. For instance, CAIDA builds router level topologies on top of IP level traces obtained with traceroute. The resulting ... [more ▼]

For years, Internet topology research has been conducted through active measurement. For instance, CAIDA builds router level topologies on top of IP level traces obtained with traceroute. The resulting graphs contain a significant amount of nodes with a very large degree, often exceeding the actual number of interfaces of a router. Although this property may result from inaccurate alias resolution, we believe that opaque MPLS clouds made of invisible tunnels are the main cause. Using Layer-2 technologies such as MPLS, routers can be configured to hide internal IP hops from traceroute. Consequently, an entry point of an MPLS network appears as the neighbor of all exit points and the whole Layer-3 network turns into a dense mesh of high degree nodes. This paper tackles three problems: the revelation of IP hops hidden by MPLS tunnels, the MPLS deployment underestimation, and the overestimation of high degree nodes. We develop new measurement techniques able to reveal the presence and content of invisible MPLS tunnels. We assess them through emulation and cross-validation and perform a large-scale measurement campaign targeting suspicious networks on which we apply statistical analysis. Finally, based on our dataset, we look at basic graph properties impacted by invisible tunnels. [less ▲]

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