1,720,958 research outputs found
Realizzazione di un simulatore di guida motociclistico
Full text linkThis work deals with the developing a driving simulator motorcycle from the definition of the mathematical model of the vehicle until the completion of a working prototype.
The purposes of a driving simulator can be very different: from the training of beginning users, to the help for ergonomic design, from the development of systems to help driving to the design of a new vehicle. In last years, moreover, the problem of road safety has given a new input to the realization of driving simulators with the aim to prepare the driver to interpret and deal with the danger that may face when using the medium.
In chapter 1 it defines the simulators, especially those driving, their purpose, their current applications and perspective and it identifies the main elements constituents. The driving simulators differ among themselves depending on the use, on the level of representation of the movement and on command acquired.
Chapters 2 and 3 there is shown the driving simulator made in its hardware and software. Here it is the description of the kinematic structure with degrees of freedom and the implementation of control and motion system, command acquisition system and representation of the virtual environment. The management of simulation is done through a main program which is presented in its fundamental components.
For movements and acquisition systems are presented major problems encountered during construction and the solutions adopted.
Finally, in chapter 4 are the results obtained during the verification tests and development of the system. They consist of the construction of some virtual motorcycle models, in statistical analysis of the answers given by a group of pilots and biomechanical tests
Experimental modal analysis of two-wheeled vehicles. Prediction of the response to road unevenness
No full textThe experimental study of the vibrations of two-wheeled vehicles gives useful results when it is carried out exciting the whole vehicle through the wheels. Modal analysis techniques make it possible to identify both in-plane modes, which influence comfort, and out-of-plane modes, which influence stability and handling. In the paper some results in terms of natural frequencies, damping coefficients and modal shapes are presented. The possibility of predicting the comfort on the road making use of the transfer functions measured in laboratory test is highlighted
A motorcycle riding simulator for assessing the riding ability and for testing rider assistance systems
No full textThis paper deals with the motorcycle riding simulator that has been developed at the
Department of Mechanical Engineering (DIM) in order to assess the riding ability and to study
man-vehicle interaction in safe conditions. The development of a mechanical system well
suited to simulate motorcycle dynamics, real time simulation and the generation of satisfactory
motion and visual cues of typical motorcycle maneuvers were the main design issues. The
reduction of costs and of overall dimensions was important as well.
The simulator consists of four sub-systems: a 5 degree-of-freedom serial motion system that
generates motion cues; a visual system that generates visual cues; a sensors system that
monitors rider’s control actions; a powerful multi-body code that simulates vehicle dynamics.
Only one PC is needed for governing the whole syste
Measurement and identification of the vibrational characteristics of motorcycle riders
No full textThis paper shows the experimental responses of five riders to roll and steer oscillations. The analysis is
carried out to identify the properties of a rider multi-body model, which can be useful for simulation. The
riders have different physiques and riding experience and are excited by means of the motorcycle riding
simulator developed at DIM. A stepped sine testing is performed. The results of the steer tests are
presented in terms of FRFs between the angular acceleration of the steer and the steering torque. A multibody
model is used to fit the experimental data. The results of the roll tests are presented in terms of FRFs
between the accelerations measured at three point of the body of the rider (head, shoulders, torso) and the
acceleration of a point placed at a fixed distance from the oscillation axis. To clarify the dynamic response
of the rider, a relative motion FRF is calculated as well: it is the ratio between the relative tangential
acceleration and the acceleration at the same point caused only by the roll angular acceleration
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
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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