1,721,014 research outputs found
Compact tracking of surgical instruments through structured markers
No full textVirtual and augmented reality surgery calls for reliable and efficient tracking of the surgical instruments in the virtual or real operating theatre. The most diffused approach uses three or more not aligned markers, attached to each instrument and surveyed by a set of cameras. However, the structure required to carry the markers does modify the instrument's mass distribution and can interfere with surgeon movements. To overcome these problems, we propose here a new methodology, based on structured markers, to compute the six degrees of freedom of a surgical instrument. Two markers are attached on the instrument axis and one of them has a stripe painted over its surface. We also introduce a procedure to compute with high accuracy the markers center on the cameras image, even when partially occluded by the instrument's axis or by other structures. Experimental results demonstrate the reliability and accuracy of the proposed approach. The introduction of structured passive markers can open new possibilities to accurate tracking, combining markers detection with real-time image processing
Enhancing Door-Status Detection for Autonomous Mobile Robots during Environment-Specific Operational Use
Full text linkDoor-status detection, namely recognizing the presence of a door and its
status (open or closed), can induce a remarkable impact on a mobile robot's
navigation performance, especially for dynamic settings where doors can enable
or disable passages, changing the topology of the map. In this work, we address
the problem of building a door-status detector module for a mobile robot
operating in the same environment for a long time, thus observing the same set
of doors from different points of view. First, we show how to improve the
mainstream approach based on object detection by considering the constrained
perception setup typical of a mobile robot. Hence, we devise a method to build
a dataset of images taken from a robot's perspective and we exploit it to
obtain a door-status detector based on deep learning. We then leverage the
typical working conditions of a robot to qualify the model for boosting its
performance in the working environment via fine-tuning with additional data.
Our experimental analysis shows the effectiveness of this method with results
obtained both in simulation and in the real-world, that also highlight a
trade-off between costs and benefits of the fine-tuning approach
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
An intelligent game engine for the at-home rehabilitation of stroke patients
No full textThe recent availability of advanced video game interfaces (such as the Microsoft Kinect, the Nintendo WiiMote and Balance Board) is creating interesting opportunities to provide low-cost rehabilitation at-home for patients. In this context, video games are rising as promising tools to guide patients through their recovery experience and to increase their motivation throughout the rehabilitation path. However, to be applied to clinical scenarios, video games must be designed to adhere to the clinical requirements and to meet doctors/patients expectations. They also need to be integrated within multi-level platforms that can allow different levels of monitoring, e.g., at a personal level by the therapist, at the hospital level by the doctors, and at the regional level by the government agencies. In this paper, we overview an intelligent game engine for the at-home rehabilitation of stroke patients The engine provides several games that implement actual rehabilitation exercises and have been developed in strict collaboration with therapists. It is integrated in a patient station that provides several types of monitoring and feedback using virtual and/ or human therapists
The design of a comprehensive game engine for rehabilitation
No full textPhysical and cognitive rehabilitation under the form of therapeutic videogames has been growing in popularity over the last years. Many rehabilitation games (or exergames) have been created with the intent to promote functional rehabilitation in a highly motivational environment. However, such exergames are often created as standalone products typically designed to target a specific exercise. Accordingly, they are usually difficult to integrate in a more structured therapy and also have very different and varied features. There is therefore a need in this area for a more holistic approach with game engines specifically designed for rehabilitation that would represent the next step in this field to guarantee efficacy, accessibility and motivational factors of exergames. In this paper, we present our Intelligent Game Engine for Rehabilitation (IGER) that tries to address these issues; we highlight the features it supports, we present some of the games we created with it, and the initial results we achieved so far
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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