1,721,016 research outputs found
Instrumented crutches for gait parameters evaluation
Full text linkMost of the prototypes of instrumented crutches available in the literature require external motion capture devices to perform a gait analysis and to report the load applied on the crutches with respect to the gait cycle. Motion capture systems with markers require a controlled laboratory with cameras, instead IMU-based systems are more transportable, but the user must be instrumented. A new version of instrumented crutches, previously developed by the authors, allows one to measure the axial forces and to detect the gait phases during two-point assisted walking thanks to the cameras mounted on the lower part of the crutches
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
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
Body measurement estimations using 3D scanner for individuals with severe motor impairments
No full textIn biomechanics, a still unresolved question is how to estimate with enough accuracy the volume and mass of each body segment of a subject. This is important for several applications ranging from the rehabilitation of injured subjects to the study of athletic performances via the analysis of the dynamic inertia of each body segment. However, traditionally this evaluation is done by referring to anthropometric tables or by approximating the volumes using manual measurements. We propose a novel method based on the 3D reconstruction of the subject's body using the commercial low-cost camera Kinect v2. The software developed performs body segment separation in a few minutes leveraging alpha shape approximation of 3D polyhedrons to quickly compute a Montecarlo volume estimation. The procedure was evaluated on a total of 30 healthy subjects and the resulting segments' lengths and masses were compared with the literature
Development of an Eye-Tracking Method for Diagnosing Delirium: Assessing Cognitive Function and Autonomic Nervous System Activity
No full textDelirium is a severe neuro-psychiatric condition characterized by a global deterioration of cognitive functions. The Confusion Assessment Method for the Intensive Care Unit scale, a test that evaluates a patient's cognitive abilities, is currently the most recommended method for assessing suspected delirium in intensive care units. However, this method faces challenges such as inadequate staff training, patient cooperation difficulties, and a lack of measurable quantitative metrics. While there are existing tests in the literature that use eye tracking to evaluate cognitive functions and assess the autonomic nervous system, there is currently no specific test available based on wearable eye tracking for diagnosing delirium. In this study, we investigated the application of a test to evaluate cognitive function and autonomic nervous system activity using eye tracking. The proposed protocol consists of four tests: the blank test, pro- and anti-saccade tests, and pupillometry test. In the first three tests, visual stimuli are presented to the subjects, and an algorithm has been developed to calculate their reaction times, which is the time interval from the presentation of the stimulus to the completion of the task. The extended uncertainty with a 95% confidence level introduced by the algorithm has been estimated as 12 ms using the Monte Carlo method. In the pupillometry test, a temporary light stimulus is provided, and parameters related to the pupil light reflex are calculated. The tests were conducted on a sample of 17 healthy male subjects, aged between 21 and 28 years, without visual or cognitive impairments. The results provide an overview of the cognitive functions and autonomic nervous system activity in the examined subjects. Additionally, the data collected from healthy subjects can be compared with individuals affected by delirium in future studies. To validate the reaction time algorithm, the Monte Carlo method was used, and a statistical analysis was conducted on the output data. The evaluation of the algorithm for detecting reaction times shows a root mean square error of 6 ms. The results of the pro- and anti-saccade tests show a statistically significant difference in detected reaction times (p-value ! 0.05), with the latter being higher due to the increased cognitive load required. The pupillometry test measured pupil light reflex parameters and compared them with those reported in the literature
Cobot user frame calibration: Evaluation and comparison between positioning repeatability performances achieved by traditional and vision-based methods
Full text linkSince cobots are designed to be flexible, they are frequently repositioned to change the production line according to the needs; hence, their working area (user frame) needs to be often calibrated. Therefore, it is important to adopt a fast and intuitive user frame calibration method that allows even non-expert users to perform the procedure effectively, reducing the possible mistakes that may arise in such contexts. The aim of this work was to quantitatively assess the performance of different user frame calibration procedures in terms of accuracy, complexity, and calibration time, to allow a reliable choice of which calibration method to adopt and the number of calibration points to use, given the requirements of the specific application. This has been done by first analyzing the performances of a Rethink Robotics Sawyer robot built-in user frame calibration method (Robot Positioning System, RPS) based on the analysis of a fiducial marker distortion obtained from the image acquired by the wrist camera. This resulted in a quantitative analysis of the limitations of this approach that only computes local calibration planes, highlighting the reduction of performances observed. Hence, the analysis focused on the comparison between two traditional calibration methods involving rigid markers to determine the best number of calibration points to adopt to achieve good repeatability performances. The analysis shows that, among the three methods, the RPS one resulted in very poor repeatability performances (1.42 mm), while the three and five points calibration methods achieve lower values (0.33 mm and 0.12 mm, respectively) which are closer to the reference repeatability (0.08 mm). Moreover, comparing the overall calibration times achieved by the three methods, it is shown that, incrementing the number of calibration points to more than five, it is not suggested since it could lead to a plateau in the performances, while increasing the overall calibration time
Validation of a ROS-Based Synchronization System for Biomechanics Gait Labs
No full textExperimental tests in biomechanics are often composed of several systems and devices, each of them providing information that needs to be acquired and processed. Data synchronization is a key factor for test results that need to be properly analyzed, limiting the influence of time delays between the acquired signals. Standard synchronization protocols are applied in different fields, from industry to telecommunications, but the hardware and software requirements for their implementation are normally difficult to be applied in biomechanics laboratories where instrumentation and protocols are likely to be changed over different experiments. Variability of sensors in the market, experimenter's skills, and test schedules hamper the application of robust standardized synchronization protocols, leading to increase post-processing efforts and the protocol steps for data acquisition. We propose a simple and cheap solution for synchronization that can be applied in experimental scenarios such as biomechanics laboratory based on a raspberry used as a trigger-box. This solution aims to easily synchronize data in a ROS-based network with any devices handling analogic trigger signals. The proposed solution is validated by evaluating time metrics in a system composed of several trigger boxes for a multi-sensor system simulation. The performed validation confirms the applicability of this solution for biomechanic tests with a wide margin of tolerance
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
- …
