5,019 research outputs found
Predicting Landslides Using Locally Aligned Convolutional Neural Networks
Landslides, movement of soil and rock under the influence of gravity, are
common phenomena that cause significant human and economic losses every year.
Experts use heterogeneous features such as slope, elevation, land cover,
lithology, rock age, and rock family to predict landslides. To work with such
features, we adapted convolutional neural networks to consider relative spatial
information for the prediction task. Traditional filters in these networks
either have a fixed orientation or are rotationally invariant. Intuitively, the
filters should orient uphill, but there is not enough data to learn the concept
of uphill; instead, it can be provided as prior knowledge. We propose a model
called Locally Aligned Convolutional Neural Network, LACNN, that follows the
ground surface at multiple scales to predict possible landslide occurrence for
a single point. To validate our method, we created a standardized dataset of
georeferenced images consisting of the heterogeneous features as inputs, and
compared our method to several baselines, including linear regression, a neural
network, and a convolutional network, using log-likelihood error and Receiver
Operating Characteristic curves on the test set. Our model achieves 2-7%
improvement in terms of accuracy and 2-15% boost in terms of log likelihood
compared to the other proposed baselines.Comment: Published in IJCAI 202
Copy mechanism and tailored training for character-based data-to-text generation
In the last few years, many different methods have been focusing on using
deep recurrent neural networks for natural language generation. The most widely
used sequence-to-sequence neural methods are word-based: as such, they need a
pre-processing step called delexicalization (conversely, relexicalization) to
deal with uncommon or unknown words. These forms of processing, however, give
rise to models that depend on the vocabulary used and are not completely
neural.
In this work, we present an end-to-end sequence-to-sequence model with
attention mechanism which reads and generates at a character level, no longer
requiring delexicalization, tokenization, nor even lowercasing. Moreover, since
characters constitute the common "building blocks" of every text, it also
allows a more general approach to text generation, enabling the possibility to
exploit transfer learning for training. These skills are obtained thanks to two
major features: (i) the possibility to alternate between the standard
generation mechanism and a copy one, which allows to directly copy input facts
to produce outputs, and (ii) the use of an original training pipeline that
further improves the quality of the generated texts.
We also introduce a new dataset called E2E+, designed to highlight the
copying capabilities of character-based models, that is a modified version of
the well-known E2E dataset used in the E2E Challenge. We tested our model
according to five broadly accepted metrics (including the widely used BLEU),
showing that it yields competitive performance with respect to both
character-based and word-based approaches.Comment: ECML-PKDD 2019 (Camera ready version
Lobbying in a multidimensional policy space with salient issues
We present a citizen-candidate model on a multidimensional policy space with lobbying, where citizens regard some issues more salient than others. We find that special interest groups that lobby on less salient topics move the implemented policy closer to their preferred policy, compared to the ones that lobby on more salient issues. When we introduce two types of citizens, who differ with respect to the salience of issues, we find pooling equilibria where voters are not able to offset the effect of lobbying on the implemented policy. This result is in sharp contrast with previous work on unidimensional citizen-candidate models that predict the irrelevance of lobbying on the implemented policy. In an extension of the model we provide citizens with the possibility of giving monetary contributions to lobbies in order to increase their power. With more than one lobby per dimension we have two findings. First, under some conditions only the most extreme lobbies receive contributions. Second, the effectiveness of a lobby is maximized when the salience of an issue is low in the population and high for a small group of citizens
Steady-state Modelling of a Vapor Compression Refrigeration Cycle
In this work a steady-state model of a simple vapor compression refrigeration cycle is presented. All the fundamental components of this system are modeled separately in order to consider them as black boxes that take inputs and convert them into output variables. The heat exchangers are treated as a set of multiple zones, identified by the refrigerant's state, connected in series, in which the heat transfer coefficient (HTC) is constant. A non-linear system of equations is obtained applying the energy balances and the ε-NTU method for each zone in the heat exchangers. A study on the HTC correlations used to connect the length of the zones with the value of the respective HTC is developed. The compressor is modeled using a polynomial function. Some iterative methods for the resolution in Matlab of the models of the components and the machine are presented, focusing on the strategy to decrease the execution time and to increase the accuracy of the results. Finally, all the models are validated through a set of experimental data and the global model is used to make some considerations about the efficiency and the exergy destruction in the plant
Sirplus - A Task Management System for Individuals with Executive Dysfunction
A significant portion of the population struggles with executive functioning and task management. This project explores the pain points for organizing, initiating, and finishing tasks and proposes a design to address these problems. The objective of this project is to relieve the stress and anxiety people with executive dysfunction often experience with tasks. The design process for this project considered different product and interface strategies to help users with their tasks through positive motivation and rewards. Initial user testing showed that information overload and forgetfulness were barriers to setting and managing tasks. Furthermore, the act of crossing an item off of a list was found to be satisfying and encouraged users to keep completing tasks. The final solution employs a three-part internet of things (IoT) system which incorporates a device for building the habit of setting daily tasks, a user interface (UI) which prevents users from being overwhelmed or overstimulated, and a gratifying, tactile task completion action
Medical SLAM in an autonomous robotic system
One of the main challenges for computer-assisted surgery (CAS) is to determine the intra-operative morphology and motion of soft-tissues. This information is prerequisite to the registration of multi-modal patient-specific data for enhancing the surgeon’s navigation capabilities by observing beyond exposed tissue surfaces and for providing intelligent control of robotic-assisted instruments. In minimally invasive surgery (MIS), optical techniques are an increasingly attractive approach for in vivo 3D reconstruction of the soft-tissue surface geometry. This thesis addresses the ambitious goal of achieving surgical autonomy, through the study of the anatomical environment by Initially studying the technology present and what is needed to analyze the scene: vision sensors. A novel endoscope for autonomous surgical task execution is presented in the first part of this thesis. Which combines a standard stereo camera with a depth sensor. This solution introduces several key advantages, such as the possibility of reconstructing the 3D at a greater distance than traditional endoscopes. Then the problem of hand-eye calibration is tackled, which unites the vision system and the robot in a single reference system. Increasing the accuracy in the surgical work plan. In the second part of the thesis the problem of the 3D reconstruction and the algorithms currently in use were addressed. In MIS, simultaneous localization and mapping (SLAM) can be used to localize the pose of the endoscopic camera and build ta 3D model of the tissue surface. Another key element for MIS is to have real-time knowledge of the pose of surgical tools with respect to the surgical camera and underlying anatomy. Starting from the ORB-SLAM algorithm we have modified the architecture to make it usable in an anatomical environment by adding the registration of the pre-operative information of the intervention to the map obtained from the SLAM. Once it has been proven that the slam algorithm is usable in an anatomical environment, it has been improved by adding semantic segmentation to be able to distinguish dynamic features from static ones. All the results in this thesis are validated on training setups, which mimics some of the challenges of real surgery and on setups that simulate the human body within Autonomous Robotic Surgery (ARS) and Smart Autonomous Robotic Assistant Surgeon (SARAS) projects
Medical SLAM in an autonomous robotic system
One of the main challenges for computer-assisted surgery (CAS) is to determine the intra-operative morphology and motion of soft-tissues. This information is prerequisite to the registration of multi-modal patient-specific data for enhancing the surgeon’s navigation capabilities by observing beyond exposed tissue surfaces and for providing intelligent control of robotic-assisted instruments. In minimally invasive surgery (MIS), optical techniques are an increasingly attractive approach for in vivo 3D reconstruction of the soft-tissue surface geometry. This thesis addresses the ambitious goal of achieving surgical autonomy, through the study of the anatomical environment by Initially studying the technology present and what is needed to analyze the scene: vision sensors. A novel endoscope for autonomous surgical task execution is presented in the first part of this thesis. Which combines a standard stereo camera with a depth sensor. This solution introduces several key advantages, such as the possibility of reconstructing the 3D at a greater distance than traditional endoscopes. Then the problem of hand-eye calibration is tackled, which unites the vision system and the robot in a single reference system. Increasing the accuracy in the surgical work plan. In the second part of the thesis the problem of the 3D reconstruction and the algorithms currently in use were addressed. In MIS, simultaneous localization and mapping (SLAM) can be used to localize the pose of the endoscopic camera and build ta 3D model of the tissue surface. Another key element for MIS is to have real-time knowledge of the pose of surgical tools with respect to the surgical camera and underlying anatomy. Starting from the ORB-SLAM algorithm we have modified the architecture to make it usable in an anatomical environment by adding the registration of the pre-operative information of the intervention to the map obtained from the SLAM. Once it has been proven that the slam algorithm is usable in an anatomical environment, it has been improved by adding semantic segmentation to be able to distinguish dynamic features from static ones. All the results in this thesis are validated on training setups, which mimics some of the challenges of real surgery and on setups that simulate the human body within Autonomous Robotic Surgery (ARS) and Smart Autonomous Robotic Assistant Surgeon (SARAS) projects
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