1,721,127 research outputs found
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 Optimized Java Based Software Package for Biomedical Images and Volumes Processing
No full textDigital image processing is fundamental for several
biomedical applications. In this paper, we describe an efficient
software package, developed in Java, for advanced visualization
and processing of biomedical images and volumes. Actually, a
great part of biomedical applications is covered by specific
software packages: they have a lot of graphical and processing
functions in common and not any has been really optimized. The
novelty of our system, when compared to other software
developed to deal with biomedical applications, is that it is
designed to provide a unifying software solution for potentially
all biomedical applications. Another important point is the
accurate choice of the development tools which we used for our
project: ImageJ and Visualization Toolkit. A detailed description
of the usage of these tools into the project is reported. Moreover,
a case study is presented and discussed
INVESTIGATION OF SOME BETA-LACTAM ANTIBIOTICS BY MEANS OF 2-35 KeV CESIUM ION BOMBARDMENT
No full textDesign of an acquisition-reconstruction algorithm for magnetic resonance surface scanner
No full textCharacterisation of a Coding/Reconstruction Algorithm on MRI Simulated Noisy Data
No full textIn Magnetic Resonance Imaging (MRI), the presence of static magnetic field in-homogeneities introduces distortions and artifacts in the images. A coding/reconstruction algorithm for MRI, based on the assignment of different time varying frequencies (accelerations) to different spatial positions, has been tested on simulated noisy data. Results, demonstrating the method is not conditioned neither by the presence of static magnetic field in-homogeneity nor by the presence of noise, are reported. In particular, the results demonstrated that noise was not incremented and the signal was unaffected by blurring or distortions
A Numerical Hand Model for a Virtual Glove Rehabilitation System
No full textHand rehabilitation, following stroke or hand surgery, is a repetitive and long duration therapy that can be facilitated with the assistance of gloves based on sensors. These devices can be substituted by a simple and inexpensive system based on the images acquired by 4 cameras and numerical analysis. In this paper we present a numerical hand model used in this system which describes the kinematic of the hand. Preliminary experimental data to test the proposed model have also been reported
Smart Algorithm for the Acquisition of the Optimal Set of Projections for Functional MRI
No full textReconstruction from projections, RP (1), has been revaluated for MRI applications, especially for real time and functional MRI (fMRI). In fact, RP methods reduce
the effects due to motion because the centre of k-space is over-sampled and it is sampled at the start of the reading time, thus eliminating movement occurring in
the last period of the reading interval. Moreover RP methods improve the signal to noise ratio (SNR) in the reconstructed image as a result of over-sampling of the
central region of the k-space. It has been demonstrated elsewhere (2) that it may be possible to reduce the number of collected projections, below the minimum
required to obtain an image of a given dimension without artefacts, if information about sample internal symmetries and shape can be collected during acquisition.
In fact, the method presented in (2) is able to collect a near optimal set of projections without any a-priori information about the sample, by calculating the
information content of the projections through an entropy function, during the progress of the acquisition process (for this reason, we refer to it as the blind
adaptive method). This method, suffers from two limitations: some important projections are excluded from the acquired set, especially in the proximity of entropy
function minima or maxima; it is necessary to use efficient software (dedicated hardware is also to be recommended) to calculate the information content of the
collected projections during the sequence repetition time, without wasting time. Aims of this work is to overcome these limitations by presenting a method which
collects a-priori information about the sample through the preliminary measurement of two circular paths at different distances from the k-space centre. The
directions of the most informative projections can then be set using information acquired from the power spectra of these paths of coefficients
A Segmentation Algorithm for X-ray 3D Angiography and Vessel Catheterization
No full textVessel Catheterization is a clinical procedure usually performed by a specialist by means of X-ray fluoroscopic guide with contrast-media. In the present paper, we present a simple and efficient algorithm for vessel segmentation which allows vessel separation and extraction from the background (noise and signal coming from other organs). This would reduce the number of projections (X-ray scans) to reconstruct a complete and accurate 3D vascular model and the radiological risk, in particular for the patient. In what follows, the algorithm is described and some preliminary experimental results are reported illustrating the behaviour of the proposed method
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