1,720,964 research outputs found
Generative design and topology optimization of disk brake floating carrier
No full textIn the last past years, computer-Aided technologies to improve existing products by widening the design space have been largely investigated. Topology optimization and generative design are two of the most representative technologies of such kind. This paper aims at investigating the use of generative design and topology optimization techniques to improve products whose design has not changed radically over the years. The product under investigation is a disk brake floating caliper that is the most common solution for commercial vehicles. In general, increasing the stiffness of the floating caliper while keeping its weight under control is desirable both from performance and fuel consumption point of view. The solution here proposed aims at exploiting two new ways to approach the engineering design process and evaluate which one is more suitable for problems of this kind. Starting from the original carrier shape, acquired with laser scanning, the two technologies have been applied on the same initial conditions. The initial design space volume corresponds to the acquired shape, the loads and the constraints for the simulation have been drawn reasonably to resemble the actual operating conditions. Keeping the input parameters constants, two different off-The-shelf software packages have been used to perform the computation and with the objective of maximizing the stiffness of the carrier while reducing its mass. The comparison and the improvements on the final designs have been drawn taken as reference to the original caliper.
DESIGN INNOVATION of BICYCLE FRAMES EXPLOITING TOPOLOGY OPTIMIZATION
No full textIn recent years, the use and demand of bicycles have increased thanks to the growing attention to the environment and due to the COVID-19 pandemic situation. At the same time, the design of the bicycles has remained substantially unchanged, improving in materials and components technology. In the off-road sector, two diametrically opposed categories have emerged in terms of comfort and pedalling efficiency. The goal of this research is to introduce a first methodological approach for the optimization of a mountain bike frame. The behaviour of the developed frame aims to combine the pedalling benefits now available only in different and non-comparable bicycle configurations. The first step concerns the modelling of a generic off-road bicycle frame, then its behaviour has been simulated for specific load cases. Subsequently, the part of the bicycle that best performed the double function of compliance and rigidity has been sought through an analysis of the strain energy using FE simulations. Hence, the reference region has been topologically optimized to provide adequate chassis travel performance. The analysis scheme has been iteratively repeated also on other parts of the frame until an acceptable solution is obtained for the utilize presented. The final configuration permits a rear tube and bottom bracket displacement of 10.4 mm and 2.4 mm compared to the 0.5 mm and 0.4 mm of the original frame respectively. The approach described can be proposed as a support for the search for an innovative design for products with unchanged geometries due to the inertia of the designers. At the same time, this methodology aims to expand the possible use of topological optimization, moving away from the classic constraint schemes present in various software
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
COLLABORATIVE ROBOTICS AND ERGONOMICS: A SCIENTIFIC REVIEW
No full textCollaborative robotics, or Human-Robot Collaboration (HRC), is a challenging topic characterized by multidisciplinary approaches. Many researchers are facing this innovative manufacturing system studying several aspects such as task allocation, facility layout problem and timing. Above all, one of the most important issues in collaborative robotics is the wellbeing of the operator collaborating with the robot system during the different phases of the process. The added value of a collaborative workplace respect to the manual and automatic workplaces is strictly correlated to a safe and ergonomic interaction between the operator and the robot. Indeed, the combination of robot and operator skills lead to a higher level of accuracy and flexibility. Thus, assessing operator's working conditions requires the acquisition, eventually in real time, of relevant parameters such as posture, movements, and interactive tasks. This may require the adoption of existing metrics proposed by standard evaluation guidelines, as well as the introduction of new or modified prescription to consider the presence of the robot. The ergonomics analysis in collaborative robotics is evaluated by considering both physical and cognitive aspects of the operator during the interaction with the robot. The research work aims to carry out a scientific bibliometric literature review (BLR) about the ergonomics analysis of collaborative workplaces, and to identify methods and tools for the physical and cognitive ergonomics assessment that can be adopted in collaborative robotics. The search has been accomplished using the Scopus database by means of a set of key words specifically defined to investigate the ergonomics in the collaborative robotics. The review provides a sharp classification, a critical analysis of the most relevant contributions in this field so that emerging trends for future development can be defined and discussed
Goalkeeper’s Performances Assessed with Action Cameras Based Mocap System
No full textThe research work presents a specific procedure to evaluate the performance of soccer goalkeepers by means of a marker-less motion capture (Mocap) system based on a set of 8 GoPro active cameras. The layout of the sensors and the calibration phase have been defined to be easily replicated and not to interfere with athletes and trainers during the exercises. The proposed solution has been tested in collaboration with goalkeeper coaches, who made available the knowledge about conventional training exercise. The Mocap system has been tested by involving two goalkeepers and a coach. The results have been elaborated and the outcomes have been considered interesting by experts. Furthermore, the adopted technology for motion capture and elaboration could be evaluated for an application to the rehabilitation process of an athlete after an injury, to determine his stage of recovery and the most suitable work to be done
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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