Integrated methods and scenario development for urban groundwater management and protection during tunnel road construction: a case study of urban hydrogeology in the city of Basel, Switzerland

In the northwestern area of Basel, Switzerland, a tunnel highway connects the French highway A35 (Mulhouse-Basel) with the Swiss A2 (Basel-Gotthard-Milano). The subsurface highway construction was associated with significant impacts on the urban groundwater system. Parts of this area were formerly contaminated by industrial wastes, and groundwater resources are extensively used by industry. During some construction phases, considerable groundwater drawdown was necessary, leading to major changes in the groundwater flow regime. Sufficient groundwater supply for industrial users and possible groundwater pollution due to interactions with contaminated areas had to be taken into account. A groundwater management system is presented, comprising extensive groundwater monitoring, high-resolution numerical groundwater modeling, and the development and evaluation of different scenarios. This integrated approach facilitated the evaluation of the sum of impacts, and their interaction in time and space with changing hydrological boundary conditions. For all project phases, changes of the groundwater system had to be evaluated in terms of the various goals and requirements. Although the results of this study are case-specific, the overall conceptual approach and methodologies applied may be directly transferred to other urban area

Reinforcement Learning in Sparse-Reward Environments with Hindsight Policy Gradients

A reinforcement learning agent that needs to pursue different goals across episodes requires a goal-conditional policy. In addition to their potential to generalize desirable behavior to unseen goals, such policies may also enable higher-level planning based on subgoals. In sparse-reward environments, the capacity to exploit information about the degree to which an arbitrary goal has been achieved while another goal was intended appears crucial to enabling sample efficient learning. However, reinforcement learning agents have only recently been endowed with such capacity for hindsight. In this letter, we demonstrate how hindsight can be introduced to policy gradient methods, generalizing this idea to a broad class of successful algorithms. Our experiments on a diverse selection of sparse-reward environments show that hindsight leads to a remarkable increase in sample efficiency

Recurrent Neural-Linear Posterior Sampling for Nonstationary Contextual Bandits

An agent in a nonstationary contextual bandit problem should balance between exploration and the exploitation of (periodic or structured) patterns present in its previous experiences. Handcrafting an appropriate historical context is an attractive alternative to transform a nonstationary problem into a stationary problem that can be solved efficiently. However, even a carefully designed historical context may introduce spurious relationships or lack a convenient representation of crucial information. In order to address these issues, we propose an approach that learns to represent the relevant context for a decision based solely on the raw history of interactions between the agent and the environment. This approach relies on a combination of features extracted by recurrent neural networks with a contextual linear bandit algorithm based on posterior sampling. Our experiments on a diverse selection of contextual and noncontextual nonstationary problems show that our recurrent approach consistently outperforms its feedforward counterpart, which requires handcrafted historical contexts, while being more widely applicable than conventional nonstationary bandit algorithms. Although it is very difficult to provide theoretical performance guarantees for our new approach, we also prove a novel regret bound for linear posterior sampling with measurement error that may serve as a foundation for future theoretical work

Hindsight policy gradients

A reinforcement learning agent that needs to pursue different goals across episodes requires a goal-conditional policy. In addition to their potential to generalize desirable behavior to unseen goals, such policies may also enable higher-level planning based on subgoals. In sparse-reward environments, the capacity to exploit information about the degree to which an arbitrary goal has been achieved while another goal was intended appears crucial to enable sample efficient learning. However, reinforcement learning agents have only recently been endowed with such capacity for hindsight. In this paper, we demonstrate how hindsight can be introduced to policy gradient methods, generalizing this idea to a broad class of successful algorithms. Our experiments on a diverse selection of sparse-reward environments show that hindsight leads to a remarkable increase in sample efficiency.Comment: Accepted to ICLR 201

The interplay of phonology and orthography in visual cognate word recognition: an ERP study

This study examined the role of phonological and orthographic overlap in the recognition of cognate words by recording electrophysiological and behavioral data. One hundred and ninety-two words were selected: 96 cognate words listed according to their phonological and orthographic overlap vs. 96 noncognate words. Twenty-four proficient European Portuguese-English bilinguals performed a silent reading task with a masked priming paradigm. The results showed that phonology interacts with semantic activation at N400 modulations. Phonological priming effects were dependent on the orthographic overlap of cognate words. Thus, the distinctive processing of cognate words seems to be due to their cross-linguistic similarity, which is consistent with a localist connectionist account on cognate representation and processing.The research reported in this paper wasfunded by FCT (Foundation for Science and Technology), by NSRF (National Strategic Reference Framework), by COMPETE (Operational Agenda for Competitiveness Factors), a program created by the EU as part of the European Regional Development Fund (ERDF), (PTDC/PSI-PCO/104671/2008) and by the Spanish Ministry of Education and Science (PSI2009–12616) and Plan E

Abnormal processing of emotional prosody in Williams syndrome: an event-related potentials study

Williams syndrome (WS), a neurodevelopmental genetic disorder due to a microdeletion in chromosome 7, is described as displaying an intriguing socio-cognitive phenotype. Deficits in prosody production and comprehension have been consistently reported in behavioral studies. It remains, however, to be clarified the neurobiological processes underlying prosody processing in WS. This study aimed at characterizing the electrophysiological response to neutral, happy, and angry prosody in WS, and examining if this response was dependent on the semantic content of the utterance. A group of 12 participants (5 female and 7male), diagnosed with WS, with age range between 9 and 31 years, was compared with a group of typically developing participants, individually matched for chronological age, gender and laterality. After inspection of EEG artifacts, data from 9 participants with WS and 10 controls were included in ERP analyses. Participants were presented with neutral, positive and negative sentences, in two conditions: (1) with intelligible semantic and syntactic information; (2) with unintelligible semantic and syntactic information (‘pure prosody’ condition). They were asked to decide which emotion was underlying the auditory sentence. Atypical event-related potentials (ERP) components were related with prosodic processing (N100, P200, N300) in WS. In particular, reduced N100 was observed for prosody sentences with semantic content; more positive P200 for sentences with semantic content, in particular for happy and angry intonations; and reduced N300 for both types of sentence conditions. These findings suggest abnormalities in early auditory processing, indicating a bottomup contribution to the impairment in emotional prosody processing and comprehension. Also, at least for N100 and P200, they suggest the top-down contributions of semantic processes in the sensory processing of speech. This study showed, for the first time, that abnormalities in ERP measures of early auditory processing in WS are also present during the processing of emotional vocal information. This may represent a physiological signature of underlying impaired on-line language and socio-emotional processing.This work was supported by a Doctoral Grant (SFRH/BD/35882/2007) awarded to APP, as well as by the grant PIC/IC/83290/2007Fundação para a Ciência e a Tecnologia (FCT

Effects of Cationic Species in Salts on the Electrical Conductivity of Doped PEDOT:PSS Films

The electrical conductivity of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) films with four salts that have various cations but the same bis(trifluoromethanesulfonyl)amide (TFSI) anion was studied. We found that doping salts of small-sized cations led to better conductivity because of the improved crystalline order and p-doped level of PEDOT, as revealed by the grazing-incidence wide-angle X-ray scattering (GIWAXS) and UV-vis spectrum. This phenomenon can be rationalized with the fact that small-sized cations with stronger Coulombic interactions can lead to high doping and rearrangement of PEDOT:PSS. These findings will help to develop recipes based on the PEDOT:PSS/salt composite toward the applications for printed flexible electronics