Data-driven Flood Emulation: Speeding up Urban Flood Predictions by Deep Convolutional Neural Networks

Computational complexity has been the bottleneck of applying physically-based simulations on large urban areas with high spatial resolution for efficient and systematic flooding analyses and risk assessments. To address this issue of long computational time, this paper proposes that the prediction of maximum water depth rasters can be considered as an image-to-image translation problem where the results are generated from input elevation rasters using the information learned from data rather than by conducting simulations, which can significantly accelerate the prediction process. The proposed approach was implemented by a deep convolutional neural network trained on flood simulation data of 18 designed hyetographs on three selected catchments. Multiple tests with both designed and real rainfall events were performed and the results show that the flood predictions by neural network uses only 0.5 % of time comparing with physically-based approaches, with promising accuracy and ability of generalizations. The proposed neural network can also potentially be applied to different but relevant problems including flood predictions for urban layout planning

Sampling motif-constrained ensembles of networks

The statistical significance of network properties is conditioned on null models which satisfy spec- ified properties but that are otherwise random. Exponential random graph models are a principled theoretical framework to generate such constrained ensembles, but which often fail in practice, either due to model inconsistency, or due to the impossibility to sample networks from them. These problems affect the important case of networks with prescribed clustering coefficient or number of small connected subgraphs (motifs). In this paper we use the Wang-Landau method to obtain a multicanonical sampling that overcomes both these problems. We sample, in polynomial time, net- works with arbitrary degree sequences from ensembles with imposed motifs counts. Applying this method to social networks, we investigate the relation between transitivity and homophily, and we quantify the correlation between different types of motifs, finding that single motifs can explain up to 60% of the variation of motif profiles.Comment: Updated version, as published in the journal. 7 pages, 5 figures, one Supplemental Materia

Comparison Of Statistical Failure Models To Support Sewer System Operation

Currently, achieving appropriate operative performance of water infrastructure has become a high priority in urbanized areas. Particularly, providing reliable sewerage service is central for human well-being and its development (Kleidorfer, et al. 2013). Having that wastewater system management is an increasingly complex task due to a number of hardly predictable factors (e.g. deterioration of system components and climate variability), recent research efforts have been focusing on developing methods to identify optimum proactive rehabilitation and maintenance strategies, some of which are based on the identification of the sewerage structures in most need of attention. To meet such a goal, different forecast failure models for urban water infrastructure have been recently developed. These models are able to assess the future behavior of water supply and sewer system structures. This study presents the comparison of two different failure statistical packages for urban water systems: (a) The FAIL software that calculates failure predictions based on two alternative stochastic processes, the single-variate Poisson process and the Linear Extended Yule process (LEYP) (see Martins et al., 2013) and (b) The SIMA software that, trough out a series of statistical tests, selects a failure model that is based either on an homogeneous Poisson process (HPP), a renewal process or a non-homogeneous Poisson process (NHPP), which allows changes of trend in the failure intensity (see Rodríguez, et al. 2012). Those different statistical models are applied to two contrasting urban wastewater systems: Bogotá (Colombia, 7.5 million inhabitants) and Oeiras e Amadora (Portugal, 10.000 inhabitants). Customer complaints and failure databases were gathered in order to analyze two different types of sewer failures named sediment-related blockages and structural failures. Multiple analyses are carried out in order to assess the impact of sewer system characteristics, system complexity, spatial resolution and data availability onto models forecasting efficiency

The effectiveness of two grammar treatment procedures for children with SLI: A randomized clinical trial

Purpose: This study compared the effectiveness of two grammar treatment procedures for children with specific language impairment. Method: A double-blind superiority trial with cluster randomization was used to compare a cueing procedure, designed to elicit a correct production following an initial error, to a recasting procedure, which required no further production. Thirty-one 5-year-old children with specific language impairment participated in 8 small group, classroom-based treatment sessions. Fourteen children received the cueing approach and 17 received the recasting approach. Results: The cueing group made significantly more progress over the 8-week treatment period than the recasting group. There was a medium–large treatment effect in the cueing group and a negligible effect size in the recasting group. The groups did not differ in maintenance of treatment effects 8 weeks after treatment. In single-subject analyses, 50% of children in the cueing group and 12% in the recasting group showed a significant treatment effect. Half of these children maintained the treatment effect 8 weeks later. Conclusion: Treatment that used a structured cueing hierarchy designed to elicit a correct production following a child’s error resulted in significantly greater improvement in expressive grammar than treatment that provided a recast following an error

Reflecting on the Physics of Notations applied to a visualisation case study

This paper presents a critical reflection upon the concept of 'physics of notations' proposed by Moody. This is based upon the post hoc application of the concept in the analysis of a visualisation tool developed for a common place mathematics tool. Although this is not the intended design and development approach presumed or preferred by the physics of notations, there are benefits to analysing an extant visualisation. In particular, our analysis benefits from the visualisation having been developed and refined employing graphic design professionals and extensive formative user feedback. Hence the rationale for specific visualisation features is to some extent traceable. This reflective analysis shines a light on features of both the visualisation and domain visualised, illustrating that it could have been analysed more thoroughly at design time. However the same analysis raises a variety of interesting questions about the viability of scoping practical visualisation design in the framework proposed by the physics of notations