On the Computation of the 3D Visibility Skeleton

International audienceThe 3D visibility skeleton is a data structure that encodes the global visibility information of a set of 3D objects. While it is useful in answering global visibility queries, its large size often limits its practical use. In this paper, we address this issue by proposing a subset of the visibility skeleton, which is about $25\%$ to $50\%$ of the whole set. We show that the rest of the data structure can be recovered from the subset as needed, partially or completely. Our recovery method is efficient in the sense that it is output-dependent. We also prove that this subset is minimal for the complexity of our recovery method

Making the Invisible Visible: Action Recognition Through Walls and Occlusions

Understanding people's actions and interactions typically depends on seeing them. Automating the process of action recognition from visual data has been the topic of much research in the computer vision community. But what if it is too dark, or if the person is occluded or behind a wall? In this paper, we introduce a neural network model that can detect human actions through walls and occlusions, and in poor lighting conditions. Our model takes radio frequency (RF) signals as input, generates 3D human skeletons as an intermediate representation, and recognizes actions and interactions of multiple people over time. By translating the input to an intermediate skeleton-based representation, our model can learn from both vision-based and RF-based datasets, and allow the two tasks to help each other. We show that our model achieves comparable accuracy to vision-based action recognition systems in visible scenarios, yet continues to work accurately when people are not visible, hence addressing scenarios that are beyond the limit of today's vision-based action recognition.Comment: ICCV 2019. The first two authors contributed equally to this pape

Interação humano-robô para a transferência de objetos

Mestrado em Engenharia MecânicaRobots come into physical contact with humans under a variety of circumstances to perform useful work. This thesis has the ambitious aim of contriving a solution that leads to a simple case of physical human-robot interaction, an object transfer task. Firstly, this work presents a review of the current research within the field of Human-Robot Interaction, where two approaches are distinguished, but simultaneously required: a pre-contact approximation and an interaction by contact. Further, to achieve the proposed objectives, this dissertation addresses a possible answer to three major problems: (1) The robot control to perform the inherent movements of the transfer assignment, (2) the human-robot pre interaction and (3) the interaction by contact. The capabilities of a 3D sensor and force/tactile sensors are explored in order to prepare the robot to handover an object and to control the robot gripper actions, correspondingly. The complete software development is supported by the Robot Operating System (ROS) framework. Finally, some experimental tests are conducted to validate the proposed solutions and to evaluate the system's performance. A possible transfer task is achieved, even if some refinements, improvements and extensions are required to improve the solution performance and range.Os robôs entram em contacto físico com os humanos sob uma variedade de circunstâncias para realizar trabalho útil. Esta dissertação tem como objetivo o desenvolvimento de uma solução que permita um caso simples de interação física humano-robô, uma tarefa de transferência de objetos. Inicialmente, este trabalho apresenta uma revisão da pesquisa corrente na área da interação humano-robô, onde duas abordagens são distinguíveis, mas simultaneamente necessárias: uma aproximação pré-contacto e uma interação pós-contacto. Seguindo esta linha de pensamento, para atingir os objetivos propostos, esta dissertação procura dar resposta a três grandes problemas: (1) O controlo do robô para que este desempenhe os movimentos inerentes á tarefa de transferência, (2) a pré-interação humano-robô e (3) a interação por contacto. As capacidades de um sensor 3D e de sensores de força são exploradas com o objetivo de preparar o robô para a transferência e de controlar as ações da garra robótica, correspondentemente. O desenvolvimento de arquitetura software é suportado pela estrutura Robot Operating System (ROS). Finalmente, alguns testes experimentais são realizados para validar as soluções propostas e para avaliar o desempenho do sistema. Uma possível transferência de objetos é alcançada, mesmo que sejam necessários alguns refinamentos, melhorias e extensões para melhorar o desempenho e abrangência da solução

A glimpse of the ERM proteins

In all eukaryotes, the plasma membrane is critically important as it maintains the architectural integrity of the cell. Proper anchorage and interaction between the plasma membrane and the cytoskeleton is critical for normal cellular processes. The ERM (ezrin-radixin-moesin) proteins are a class of highly homologous proteins involved in linking the plasma membrane to the cortical actin cytoskeleton. This review takes a succinct look at the biology of the ERM proteins including their structure and function. Current reports on their regulation that leads to activation and deactivation was examined before taking a look at the different interacting partners. Finally, emerging roles of each of the ERM family members in cancer was highlighted

Assessment of the impact of the application single photon emission computerized tomography and SPECT-CT on lesion catergorization

Includes bibliographical referencesObjectives: To assess initial experience with the use of a new SPECT-CT in the evaluation of lesions. Methods: The folder number, radiopharmaceutical used and type of scan of patients examined with a new Siemens T6 SPECT-CT between 2 April and 31 December 2013 were retrieved. The number of 99m Tc -MDP bone scans was sufficient for a detailed analysis. The scans were re-processed and reported by the observer before he was given any clinical information. Whole body planar, whole body planar plus SPECT and whole body planar plus SPECT-CT images were assessed successively in three separate sessions at least two weeks apart. At each session, the certainties of detection, localisation, and categorisation of each lesion were recorded. Results: A total of 539 lesions were seen on the whole body, SPECT and CT images in 133 patients. The whole body images showed no lesions in three patients and 378 lesions in 130 patients, 117(31%) lesions in areas not covered by the SPECT. SPECT detected 122 additional lesions in 79 patients. Thirty-nine (12.2%) lesions were seen only on CT in 32 (24.1%) patients. F or the 261 lesions seen on the planar images in the SPECT FOV, lesion detection was definite in 233 (89.3%), localisation definite in 151(57.9%) and categorisation definite in 123 (47.1%) lesions. On the SPECT, definite lesion detection, localisation and categorisation were recorded respectively for 259 (99.2%), 228 (87.4%) and 176 (67.4%) of the 261 lesions. Lesion detection, localisation and categorisation certainties were definite for 100%, 99.1% and 94.7% of the SPECT-CT lesions respectively. Conclusion: Whole body planar scintigraphy is essential in lesion detection. SPECT markedly improves lesion detection and localisation and CT enhances lesion categorisation

INTEGRATING PIXOLOGIC ZBRUSH INTO AN AUTODESK MAYA PIPELINE

The purpose of this thesis is to integrate the use of the relatively new volumetric pixel program, Pixologic ZBrush, into an Autodesk Maya project pipeline. As ZBrush is quickly becoming the industry standard in advanced character design in both film and video game work, the goal is to create a succinct and effective way for Maya users to utilize ZBrush files. Furthermore, this project aims to produce a final film of both valid artistic and academic merit. The resulting work produced a guide that followed a Maya-created film project where ZBrush was utilized in the creation of the character models, as well as noting the most useful formats and resolutions with which to approach each file. A concrete method of moving files back and forth effectively from Maya to ZBrush was documented. Given the short time that ZBrush has been in use, such a consolidated guide may prove useful to anyone producing a small-scale production while maintaining quality visuals

Beyond Documentation: 3D Data in Archaeology

As the costs associated with the collection of 3D data continue to plummet, there is little doubt that the number of available archaeology-related 3D datasets will increase dramatically in the coming decade. While our analytical procedures continue to evolve as new applications are contemplated, analyses of 3D data are increasing in frequency within the archaeological literature. In this article, we seek to provide a brief overview of a few examples from our own research and explore some possibilities that may add value to existing collections. In the following pages, we discuss some of the ways that 3D data have been used in studies of morphometrics, public archaeology, excavation, and comparative endeavors

Prediction of social dynamic agents and long-tailed learning challenges: a survey

Autonomous robots that can perform common tasks like driving, surveillance, and chores have the biggest potential for impact due to frequency of usage, and the biggest potential for risk due to direct interaction with humans. These tasks take place in openended environments where humans socially interact and pursue their goals in complex and diverse ways. To operate in such environments, such systems must predict this behaviour, especially when the behavior is unexpected and potentially dangerous. Therefore, we summarize trends in various types of tasks, modeling methods, datasets, and social interaction modules aimed at predicting the future location of dynamic, socially interactive agents. Furthermore, we describe long-tailed learning techniques from classification and regression problems that can be applied to prediction problems. To our knowledge this is the first work that reviews social interaction modeling within prediction, and long-tailed learning techniques within regression and prediction