1,720,967 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
Feasibility analysis about an Electrical Impedance Tomography (EIT) wearable system
No full textThe thesis concerns the fasibility about the electrical impedance tomography (EIT) technique implemented through a device for health monitoring, the BodyGateWay (BGW), developed by STMicroelectronics at Agrate Brianza (MB).
EIT, in clinical practice, is used to provide tomographic images in a non-invasive way, by electrical measurements made from a series of electrodes on the surface of the region of interest. Nowadays the most promising applications of EIT are monitoring of patients with complications related to the respiratory system and surgery assistance for intra-surgical imaging.
BGW is a wireless wearable device for continuous remote monitoring of ECG and bio-impedance signals. It is equipped with an optimized front-end and low-power system management. The challenge of being able to implement additional functionality without drastically changing the architecture of the device have pushed the development of this work.
The first phase of the project involved the analysis of algorithms and mathematical structures developed in MATLAB environment within the EIDORS project for the solution of direct and inverse problem related to EIT. Optimal parameters, regarding methods of acquisition and matrices for conditioning of ill-posed problem (a-priori information about conductivity distribution, noise, geometrical factors) have been identified. These operations were performed through COMSOL simulation on complex anatomical models, demonstrating the feasibility of EIT image techniques reconstruction in ideal case.
The next stage involved hardware and software design of an electronic device, to be interfaced to the BGW, for automatic selection of electrodes pairs for current injection and bio-impedance acquisition. The whole system was tested on a phantom which replicated the typical conductivity of the tissues of the thoracic region.
The results led to a further optimization obtaining image quality comparable to those presented in literature.
The final tests, conducted on healthy subjects, have produced promising preliminary results, highlighting the potential offered by the implementation of this imaging methodology in a low-power device designed for continuous patient monitoring
Artifact removal in digital retinal images
Full text linkGlobally 2.2 million people are visually impaired and, of these, approximately 1 million present forms of visual impairment that could be addressed or prevented. Retinal imaging is a key step in the diagnosis and follow-up of major causes of visual impairment. As much as 20% of retinal images collected in the population are affected by artifacts, that render them ungradable both by expert graders and by the more recent automatic grading systems.;This work aims to develop an artifact removal strategy able to improve the effectiveness of retinal image grading, in particular for retinal feature segmentation. First, a large group of statistical parameters designed to measure image quality have been selected from the literature. A new ophthalmic database was then collected (CORD - the Comprehensive Ophthalmic Research Database), which includes retinal images with and without artifacts.;A mathematical model describing artifacts on the basis of the interaction of the light with the eye during eye photography was then developed. CORD and the mathematical model were then used to train a binary classifier to distinguish pixels affected by distortions within the image without the need for interpretive knowledge of the image itself and, on the basis of this, to establish a validation criterion for quality improvement in retinal images. Finally, an algorithm was developed to isolate in retinal images the regions affected by artifacts, and to subtract from the images the additive contributions to the distortion.;The artifact clean-up has been shown to increase the textural information of the retinal images, by improving vessel segmentation by more than 10%. By avoiding the use of interpretative elements of the image, this improvement in the quality of retinal images is agnostic to specific disease processes, and thus potentially applicable to population screening. Further work is necessary to improve the cosmetic quality of the images, to optimise the artifact removal strategy, and to relate the feature extraction improvement to clinical performance.Globally 2.2 million people are visually impaired and, of these, approximately 1 million present forms of visual impairment that could be addressed or prevented. Retinal imaging is a key step in the diagnosis and follow-up of major causes of visual impairment. As much as 20% of retinal images collected in the population are affected by artifacts, that render them ungradable both by expert graders and by the more recent automatic grading systems.;This work aims to develop an artifact removal strategy able to improve the effectiveness of retinal image grading, in particular for retinal feature segmentation. First, a large group of statistical parameters designed to measure image quality have been selected from the literature. A new ophthalmic database was then collected (CORD - the Comprehensive Ophthalmic Research Database), which includes retinal images with and without artifacts.;A mathematical model describing artifacts on the basis of the interaction of the light with the eye during eye photography was then developed. CORD and the mathematical model were then used to train a binary classifier to distinguish pixels affected by distortions within the image without the need for interpretive knowledge of the image itself and, on the basis of this, to establish a validation criterion for quality improvement in retinal images. Finally, an algorithm was developed to isolate in retinal images the regions affected by artifacts, and to subtract from the images the additive contributions to the distortion.;The artifact clean-up has been shown to increase the textural information of the retinal images, by improving vessel segmentation by more than 10%. By avoiding the use of interpretative elements of the image, this improvement in the quality of retinal images is agnostic to specific disease processes, and thus potentially applicable to population screening. Further work is necessary to improve the cosmetic quality of the images, to optimise the artifact removal strategy, and to relate the feature extraction improvement to clinical performance
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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