Documents found
-
371.More information
We developed an automated methodology for real-time validation of hydrometric data in a sewer network. Our methodology uses real-time validated data to optimise system management and non-real-time data to evaluate day-to-day performance.Two approaches can be used to validate and correct hydrometric data; the choice depends on the number of level gauges present in a system. In single gauge systems, univariate filtering is used to smooth data. For example, frequency filtering systematically eliminates values corresponding to frequencies higher than a predetermined threshold frequency. In systems with several gauging stations-duplex, triplex, or multiplex systems-the multivariate filtering method proposed here can be used to validate data series from each gauge. Material redundancy in duplex or higher order systems makes it possible to detect a deficient gauge, using a decision rule to set aside erroneous readings before averaging accepted values. Part of the underlying principle of this methodology is heavier reliance on gauges that give readings consistent with previous and subsequent validated values in a given series. Thus isolated positive or negative variations within a series are eliminated if corresponding variation values at other gauges are more consistent. To evaluate persistence, a reading is compared to a value predicted by an autoregressive (AR) model calibrated by the previous validated reading.This filtering technique constitutes an intelligent alternative to the frequency filtering method mentioned above. In more practical terms, it compares the deviation of an AR model prediction from a measured value with the deviation of the same AR model prediction from a value estimated by a regressive model at other stations in the network. Among the values measured and estimated by the regressive model, the one nearest the AR model prediction is retained.Our methodology also relies on analytical redundancy generated by direct measurement of flow and hydrological simulation. More precisely, the deviation of the AR model prediction from the measured value is compared with the deviation of the same AR model prediction from a value obtained from a hydrological simulation model. Among measured and simulated values, the one nearest the AR model prediction is retained. To allow consideration of nonstationary models and to avoid the well-known bias of the least squares method, the Kalman filter is used to identify the parameters of the AR model.The methodology we propose employs three models. The first generates analytical redundancy using hydrological modelling. An autoregressive model is then used to predict future runoff rate values. Finally, a voting process model is used to compare measured and simulated values.The proposed methodology was tested on the Verdun sewer system in Quebec with successful results. Two types of artificial disturbance of the measured hydrograph were created: white noise was added to measured values and disturbances of large amplitude and various forms were introduced. The methodology produced the initial values and performance criteria were conclusive. Thus on-site testing confirms that this approach allows completely automated detection and correction of most anomalies. Flood peaks were neither underestimated nor overestimated, and total runoff volumes were retained.
Keywords: Validation, redondance, débit, mesure, filtre de Kalman, autorégressif, temps réel, assainissement, Validation, redundancy, flow, measurement, Kalman filter, autoregressive, real time, sewer
-
373.More information
This article analyzes the functions and motivations of literary code-switching and code-mixing in ten contemporary heterolingual novels. A microanalysis is followed by a more general typology. Thousands of instances of code-switching or mixing were coded according to form and function variables using a grid provided by software program Sphinx-Eurêka. A cross-referencing of these variables revealed the main characteristics of each novel, which led to a typology of heterolingual writing at the end of the 20th century. This typology places the the ten novels along the levels of a three-part pyramid. At the base is a “realistic” or mimetic approach which, doubled with irony, becomes parody, and finally, at the top, is the creative approach.
Keywords: hétérolinguisme, romans plurilingues, alternances de langues, Sphinx-Eurêka, heterolingual novels, codes-switching, code-mixing, Sphinx-Eurêka
-
374.More information
Recently, many high schools in Quebec, particularly private schools, have made purchasing an iPad compulsory for all students. By doing this, these institutions have been trying to systematize tablet technology in the classroom. Nevertheless, it seems that the results of empirical research remain rather rare on the use of digital tablets in the classroom. In this article, we present some reflections on the use of iPads for the teaching of reading and writing based on a case study in which a French teacher, currently uses this technology in her classroom.
Keywords: iPad, didactique de la lecture et de l'écriture, pratiques pédagogiques, iPad, teaching reading, teaching writing, teaching practices
-
375.More information
The Hesbaye area is located in the northeastern part of Belgium. The aquifer formations consist of chalk deposits. Groundwater provides about 80,000 m3 d-1. Despite 5 to 20 meters of superficial loess deposits, the groundwater quality is threatened by increasing nitrate concentrations of 0.35 mg×L-1 per year in the semi-confined part of the aquifer to 0.7 mg×L-1 in the unconfined aquifer. Presently, nitrate concentrations are between 15 and 25 mg×L-1 in the semi-confined part of the aquifer but are more than 35 mg×L-1 (reaching locally 150 mg×L-1) in the unconfined part that covers 95% of the area. Nitrate concentrations have such a high spatial variation that various statistical treatments (such as kriging used to draw iso-concentration maps) have failed. This failure is due to the fact that the concentrations are highly influenced by surface land use (grass land, culture land, villages, point source pollutants, etc.). In addition, nitrate content in the aquifer varies vertically with decreasing values at depth (gradient of 0.7 mg×L-1 ×m-1).Aquifer parameters were determined by 38 pumping and tracer tests conducted in radial convergent or cylindrical flow at 11 sites. Results showed that hydraulic conductivity values ranged from 1 × 10-6 m×s-1 to 4 × 10-2 m×s-1 and effective porosities from 0.5% to 7%, showing that the aquifer was heterogeneous. Dispersivity values were affected by scale effects and varied according to chalk weathering or fracture zones. They ranged from less than 5 m in fractures to more than 60 m in weathered chalk (as in the upper part of the aquifer) and in the chalk matrix. In the chalk, transport processes were influenced by the immobile water effect due to diffusive transfer from the moving to the non-moving fluid. Non-effective porosity filled by non-moving fluid was estimated between 8 to 42%. The transfer constant ranged from 0.98 × 10-7 s-1 to 10 × 10-7 s-1.The determination of the transport parameters allowed simulation of nitrate transport at a regional scale. The SUFT3D (Saturated and Unsaturated Flow and Transport Model), developed by the Hydrogeology Section of the Georesources, Geotechnologies and Building Materials Department of Liege University was used. The modelled groundwater zone was defined as a 2.0 x 4.5 km rectangle of 10 km2. The aquifer was subdivided into 6 layers of 3350 cells (50 x 50 m wide and 3 to 15 m thick). Boundary flow conditions were defined as a prescribed head (Dirichlet conditions) to the north and the south of the area modelled. As the model simulations run for a time period of 30 years, the northern Dirichlet conditions had to be adapted to the regional and seasonal water table fluctuations that were observed during this period. At the south boundary, as the aquifer is drained by the river Geer, the water table is fixed at the river bed altitude. The eastern and western boundaries were, according to the regional piezometry, assumed to be impermeable. For the transport boundary conditions, prescribed flux (Cauchy conditions) was used for the aquifer top. Elsewhere Neumann conditions were usedSimulations were run for the period from 1963 to 1992. Nitrate inputs were averaged yearly and estimated according to actual input conditions. These conditions were calculated by simulation of nitrate flows through the non-saturated part of the aquifer using the EPIC-Model and taking into account the amount of nitrate fertilisers used by farmers (given by the Belgian government Statistical Institute). Initial conditions were calculated according to the 1963 nitrate inputs.Simulations demonstrated that it is important to distinguish the origin of the pollution as either point or non-point (diffuse) sources. For point source pollutants (such as contaminated infiltration basins), aquifer nitrate concentrations increased during low water level periods due to weaker dilution linked with a poor regional water gradient. During high groundwater levels, dilution is more important and the nitrate concentration decreases. If a point source pollutant is suppressed, aquifer quality is improved within one to two years. This demonstrates the importance of protective actions that could be applied within the framework of the protection zones around collecting galleries and pumping fields.For diffuse contamination the mean input over the area (10 m depth below cropped areas) increased from 1.32 × 10-7 mg×m-2 ×s-1 in 1963 to 5.14 × 10-7 mg×m-2 ×s-1 (i.e., a factor of four). According to these values, concentrations ranged from 11 mg×L-1 to 22 mg×L-1 (i.e., increasing by 0.5 mg×L-1 per year) between 1963 and 1992. Predictive simulations, using 1992 input, show that it will take more or less 30 years for the aquifer to be in equilibrium with the 1992 input. At that time the mean concentration value will be around 30 mg×L-1.The main results of the simulations clearly show that if actions are taken to decrease nitrate inputs, even if the aquifer nitrate contents rapidly react to the new input, nitrate levels will decrease slowly and take about 30 years to be in equilibrium with the new inputs. This long delay is due to the immobile water effect that is characteristic of the chalk aquifer. Thus it is important to inform environmentalists who work on action programs (such as the water directive imposed by the European Community in the vulnerable zones) that the effects of their actions must be based on 10 to 20 year scenarios. To this estimation, based on the reaction time of the aquifer to a new input, one must also add the time transfer of the pollutant through the unsaturated part of the aquifer.
Keywords: Nappe aquifère de Hesbaye, Craie, Contamination par les nitrates, Modélisation, Effet d'eau immobile, Hebaye aquifer, Chalk, Nitrate contamination, Groundwater modelling, Immobile water effect
-
376.More information
A survey of the people who frequently use homeless shelters or hot meal distribution services (l’enquête auprès des personnes fréquentant les services d’hébergement ou les distributions de repas chauds) ended with a deliberately vague question in order to give the homeless the rare opportunity to make their opinions heard. Half of the homeless people surveyed seized this chance for various reasons, and their responses were equally varied, both in terms of the issues raised and their expression. One fi fth of those surveyed talked about the survey itself, generally to rate its quality, but also to criticise it for being too long or for containing redundant questions, questionning its overall usefulness. A third focused on their diffi culties in fi nding housing or work, or even both, criticising the vicious circle in which they are trapped: they need to have a job to access housing, and vice versa. One fi fth used the opportunity to give their opinion about homeless shelters, either to praise them as part of the reintegration process, or to critisize the living conditions there. One in ten criticized the support services in general or directly criticised the support workers they had had contact with, such as social workers, whilst eight out of ten stated that they were satisfi ed with the contact they had had with the different services in other questions in the survey. Other issues were raised, but to a lesser extent, such as family, whether this be parents and confl icting relationships or the nuclear family and the diffi culty of preserving it in their circumstances, long-winded administrative procedures, life on the streets and the future. The responses to this fi nal question not only suggest new ways in which such questionnaires could be improved, but also report on the persistent problems which people without offi cial documents, couples, families and even young people face. Do the Users Have Anything to Add?
-
377.More information
A digital ethic (Rosati, 2012) is applied in education, covering topics such as respect for copyright, cyberbullying and netiquette. But where do we stand in terms of an emerging digital ethic as new forms of action arise from this specific context? To answer this question, we attempt to identify, through the hacker character, this key digital player, ethical orientations and forms of action which, while respecting the purposes of education, would change the relationship with technology. The work of hackers consists partly of understanding and modifying what Feenberg (2013) calls the codes of technology, which are made up of functions and meanings. Coding, decoding and recoding technology with an ethical aim promiting the richness of existence for oneself and others is the basis of three proposals that could foster the emergence of a digital ethic in education: hackerspaces in schools, learning the computer code, and the emergence of education on the codes of technology.
-
378.More information
In this study of interaction in a public forum and interconnection with other media on the Internet, the authors show the practical constitution of asynchronous written interaction mediated by electronic networks. The forum alone is not a framework of participation, for other network resources are mobilised during or around interactions. Personal pages and collective sites can be used as a guide, in relation to an interlocutor, and e- mail or direct conversation tools can be used in parallel or successively for private interaction. To account for the particular nature of mediated interaction, the analysis explores the types of activity in a forum, the constitution of identities and the way in which relations are built up on the network.
-
379.More information
The discourse of demands and action in [french] trade union press editorials (1966-1998)The analysis of a corpus of trade union press editorials (1996-1998) highlights the main controversies that oppose or unite the various labor federations (CGT, CFDT, FO). Using a textual analysis methodology (Alceste protocol), certain types of utterances are interpreted so as to reveal on one hand the underlying conceptual logics, and on the other, the constraints imposed by the authors' trade union positions. Demands are simultaneously themes constructed by union discourse in controversies and quasi-performatives : to demand is to update a semantic form and to seek to register it in the world of « things ». The shaping of demands is also inevitably a call to action. The analysis shows that this double thematization, characteristic of trade union discourse, produces massive effects on the « surface » of the discourses marked out by textual analysis.