Hydraulic Characterization of Porous Media for Remediation Applications in Geo-Environmental Engineering: Laboratory Experiment and Numerical Modeling

Hydraulic properties of porous media are very important characters for various geotechnical and geo-environmental applications. In this study, multi-step outflow experiments and numerical modeling were performed for homogeneous and layered column conditions with fine to coarse sands to investigate water flow mechanisms and better predict water flow and solute transport with the van Genuchten-Mualem (VGM) hydraulic model. Inversed modeling under HYDRUS-1D was performed to estimate six VGM soil hydraulic parameters. Forward modeling was conducted to evaluate the impacts of VGM hydraulic parameters along with saturated hydraulic conductivity to solute transport. Scaling effects such as column length, time, and chemical parameters were also examined. The samples tested showed that hydraulic conductivity varied between 0.88-1.06 cm/min (fine sand) and 2.54-3.84 cm/min (coarse sand), which is greater than subsurface soil (0.03-0.9 cm/min) under field condition. In addition, the sensitivity analysis was also performed to investigate the influence of input parameters. The effects of VGM hydraulics parameters and measurement accuracy on concentration breakthrough curves were examined. The coefficient of variation (CV) results showed that the two most influential parameters were the hydraulic conductivity (53-93%) and saturated water content (46-53%)

User-Aware Dialogue Management Policies over Attributed Bi-Automata

Designing dialogue policies that take user behavior into account is complicated due to user vari- ability and behavioral uncertainty. Attributed Prob- abilistic Finite State Bi-Automata (A-PFSBA) have proven to be a promising framework to develop dia- logue managers that capture the users’ actions in its structure and adapt to them online, yet developing poli- cies robust to high user uncertainty is still challenging. In this paper, the theoretical A-PFSBA dialogue man- agement framework is augmented by formally defining the notation of exploitation policies over its structure. Under such definition, multiple path based policies are implemented, those that take into account external in- formation and those which do not. These policies are evaluated on the Let’s Go corpus, before and after an online learning process whose goal is to update the ini- tial model through the interaction with end-users. In these experiments the impact of user uncertainty and the model structural learning is thoroughly analyzedSpanish Minister of Science under grants TIN2014-54288-C4- 4-R and TIN2017-85854-C4-3-R European Commission H2020 SC1-PM15 EMPATHIC project, RIA grant 69872

A proposal to manage multi-task dialogs in conversational interfaces

The emergence of smart devices and recent advances in spoken language technology are currently extending the use of conversational interfaces and spoken interaction to perform many tasks. The dialog management task of a conversational interface consists of selecting the next system response considering the user's actions, the dialog history, and the results of accessing the data repositories. In this paper we describe a dialog management technique adapted to multi-task conversational systems. In our proposal, specialized dialog models are used to deal with each specific subtask of dialog objective for which the dialog system has been designed. The practical application of the proposed technique to develop a dialog system acting as a customer support service shows that the use of these specialized dialog models increases the quality and number of successful interactions with the system in comparison with developing a single dialog model

Four-in-One: A Joint Approach to Inverse Text Normalization, Punctuation, Capitalization, and Disfluency for Automatic Speech Recognition

Features such as punctuation, capitalization, and formatting of entities are important for readability, understanding, and natural language processing tasks. However, Automatic Speech Recognition (ASR) systems produce spoken-form text devoid of formatting, and tagging approaches to formatting address just one or two features at a time. In this paper, we unify spoken-to-written text conversion via a two-stage process: First, we use a single transformer tagging model to jointly produce token-level tags for inverse text normalization (ITN), punctuation, capitalization, and disfluencies. Then, we apply the tags to generate written-form text and use weighted finite state transducer (WFST) grammars to format tagged ITN entity spans. Despite joining four models into one, our unified tagging approach matches or outperforms task-specific models across all four tasks on benchmark test sets across several domains

Design of a Wearable Ultrasound System

Ultrasound imaging is a safe and powerful tool for providing detailed still and moving images of the human body. Most of today’s ultrasound systems are housed on a movable cart and designed for use within a clinical setting, such as in a hospital or doctor’s office. This configuration hinders its use in locations lacking controlled environments and stable power sources. Example locations include ambulances, disaster sights, war zones and rural medicine. A wearable ultrasound system, in the form of a vest worn by a sonographer, has been developed as a complete solution for performing untethered ultrasound examinations. The heart of the system is an enclosure containing an embedded computer running the Windows XP operating system, and a custom power supply. The power supply integrates a battery charger, a switching regulator, two linear regulators, a variable speed fan controller and a microcontroller providing an interface for monitoring and control to the embedded computer. Operation of the system is generally accomplished through the use of voice commands, but it may also be operated using a hand-held mouse. It is capable of operating for a full day, using two batteries contained in the vest. In addition, the system has the capability to wirelessly share live images with remote viewers in real-time, while also permitting full duplex voice communication. An integrated web-server also provides for the wireless retrieval of stored images, image loops and other information using a web-browser