Fast Graph-Based Object Segmentation for RGB-D Images

Object segmentation is an important capability for robotic systems, in particular for grasping. We present a graph- based approach for the segmentation of simple objects from RGB-D images. We are interested in segmenting objects with large variety in appearance, from lack of texture to strong textures, for the task of robotic grasping. The algorithm does not rely on image features or machine learning. We propose a modified Canny edge detector for extracting robust edges by using depth information and two simple cost functions for combining color and depth cues. The cost functions are used to build an undirected graph, which is partitioned using the concept of internal and external differences between graph regions. The partitioning is fast with O(NlogN) complexity. We also discuss ways to deal with missing depth information. We test the approach on different publicly available RGB-D object datasets, such as the Rutgers APC RGB-D dataset and the RGB-D Object Dataset, and compare the results with other existing methods

Strutture portanti - Aspetti progettuali e normativi

Comitato tecnico scientifico in materia di rischio sismico (istituito con Delibera Giunta Regionale n. 606 del 21/6/2010) Orientamenti interpretativi in merito a interventi locali o di riparazione in edifici esistenti (modifica e sostituisce quello ratificato nella seduta CTS del 21.7.2010. Aggiornamento del 3/10/2012 - Parte 1/

Equivalent-Circuit Models for the Design of Metamaterials Based on Artificial Magnetic Inclusions

Cataloged from PDF version of article.In this paper, we derive quasi-static equivalent-circuit models for the analysis and design of different types of artificial magnetic resonators-i.e., the multiple split-ring resonator, spiral resonator, and labyrinth resonator-which represent popular inclusions to synthesize artificial materials and metamaterials with anomalous values of the permeability in the microwave and millimeter-wave frequency ranges. The proposed models, derived in terms of RLC equivalent circuits, represent an extension of the models presented in a recent publication. In particular, the extended models take into account the presence of a dielectric substrate hosting the metallic inclusions and the losses due to the finite conductivity of the conductors and the finite resistivity of the dielectrics. Exploiting these circuit models, it is possible to accurately predict not only the resonant frequency of the individual inclusions, but also their quality factor and the relative permeability of metamaterial samples made by given arrangements of such inclusions. Finally, the three models have been tested against full-wave simulations and measurements, showing a good accuracy. This result opens the door to a quick and accurate design of the artificial magnetic inclusions to fabricate real-life metamaterial samples with anomalous values of the permeability

Análisis del impacto de heurísticas en la toma de decisiones en condiciones de incertidumbre en PyMEs

Las decisiones y la incertidumbre son parte de la vida. Dentro de las teorías clásicas de la elección y los métodos cuantitativos, se encuentran los árboles de decisión. Éstos emplean el teorema de Bayes y el criterio del valor esperado, proponiendo la mejor alternativa. Sin embargo, el individuo ilimitadamente racional que suponen los clásicos no describe fielmente la realidad. Se ha probado que sus decisiones se encuentran afectadas por heurísticas y sesgos, los cuales están incorporados en los nuevos modelos conductuales. Este escenario no sólo se visualiza en individuos, sino también en organizaciones. La problemática se acrecienta en las PyMEs, producto de su particular caracterización. Así, el objetivo de este artículo es presentar las heurísticas más observadas en las decisiones de empresarios PyME de la región de Bahía Blanca. La metodología empleada fue el panel de expertos. Se les presentó a docentes investigadores de dos universidades locales y a referentes de instituciones relacionadas con PyMEs nueve heurísticas, para que definieran el nivel de presencia de cada una. Se concluyó que lasDecisions and uncertainty are part of life. Within the classical theories of choice and quantitative methods, we could find decision trees. They use Bayes theorem and the expected value criterion proposing the best alternative. However, the unlimited rational individual defined by the classics does not truly describe reality. It has been proven that their decisions are influenced by heuristics and biases, which are now added to the new behaviour models. This structure is not only observed in individuals but in organizations as well. And it is increased in SMEs as a result of their peculiar characteristics. For this reason, the objective of this article is to present the most commonly observed heuristics in the decisions made by SMEs business managers in the region of Bahía Blanca. The methodology employed a panel of experts. Nine heuristics were submitted to researcher professors of two local universities as well as to representatives of institutions related to SMEs in order for them to define the level of occurrence of each one. It was concluded that the most observed ones were: Availability, Representativeness, and Overconfidence.Fil: Manzanal, Melisa Noemí. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Ciencias de la Administración; ArgentinaFil: Milanesi, Gastón S.. Universidad Nacional del Sur. Departamento de Ciencias de la Administración; ArgentinaFil: Vigier, Hernan Pedro. Provincia de Buenos Aires. Dirección General de Cultura y Educación. Universidad Provincial del Sudoeste; ArgentinaFil: Toscana, Lidia. Universidad Nacional del Sur. Departamento de Ciencias de la Administración; Argentin

A Low-cost Open Source 3D-Printable Dexterous Anthropomorphic Robotic Hand with a Parallel Spherical Joint Wrist for Sign Languages Reproduction

We present a novel open-source 3D-printable dexterous anthropomorphic robotic hand specifically designed to reproduce Sign Languages' hand poses for deaf and deaf-blind users. We improved the InMoov hand, enhancing dexterity by adding abduction/adduction degrees of freedom of three fingers (thumb, index and middle fingers) and a three-degrees-of-freedom parallel spherical joint wrist. A systematic kinematic analysis is provided. The proposed robotic hand is validated in the framework of the PARLOMA project. PARLOMA aims at developing a telecommunication system for deaf-blind people, enabling remote transmission of signs from tactile Sign Languages. Both hardware and software are provided online to promote further improvements from the community

From text to dictionary.: Steps for a computerised process.

The aim of this study is to illustrate the state of-the art of technical tools which allow the user to build the lexicon of a Swahili text. Different kinds of statistical information can also be extracted from the text with the aid of tailor made software. The basic operation in building the lexicon of a text is lemmatization, i. e extracting the lemma from the forms contained in the text. Once the lemma list is ready it can be converted into a list of entties, to be filled according to selected criteria

Physical Interaction of Autonomous Robots in Complex Environments

Recent breakthroughs in the fields of computer vision and robotics are firmly changing the people perception about robots. The idea of robots that substitute humansisnowturningintorobotsthatcollaboratewiththem. Serviceroboticsconsidersrobotsaspersonalassistants. Itsafelyplacesrobotsindomesticenvironments in order to facilitate humans daily life. Industrial robotics is now reconsidering its basic idea of robot as a worker. Currently, the primary method to guarantee the personnels safety in industrial environments is the installation of physical barriers around the working area of robots. The development of new technologies and new algorithms in the sensor field and in the robotic one has led to a new generation of lightweight and collaborative robots. Therefore, industrial robotics leveraged the intrinsic properties of this kind of robots to generate a robot co-worker that is able to safely coexist, collaborate and interact inside its workspace with both personnels and objects. This Ph.D. dissertation focuses on the generation of a pipeline for fast object pose estimation and distance computation of moving objects,in both structured and unstructured environments,using RGB-D images. This pipeline outputs the command actions which let the robot complete its main task and fulfil the safety human-robot coexistence behaviour at once. The proposed pipeline is divided into an object segmentation part,a 6D.o.F. object pose estimation part and a real-time collision avoidance part for safe human-robot coexistence. Firstly, the segmentation module finds candidate object clusters out of RGB-D images of clutter scenes using a graph-based image segmentation technique. This segmentation technique generates a cluster of pixels for each object found in the image. The candidate object clusters are then fed as input to the 6 D.o.F. object pose estimation module. The latter is in charge of estimating both the translation and the orientation in 3D space of each candidate object clusters. The object pose is then employed by the robotic arm to compute a suitable grasping policy. The last module generates a force vector field of the environment surrounding the robot, the objects and the humans. This force vector field drives the robot toward its goal while any potential collision against objects and/or humans is safely avoided. This work has been carried out at Politecnico di Torino, in collaboration with Telecom Italia S.p.A