1,720,971 research outputs found
Semi-Automated Methods For Femur Length Measurements In Fetal Ultrasound Images
No full textMeasurement of fetal femur length is crucial for the estimation of fetal age and growth pattern. An automatic system for femur recognition and measurement in ultrasound images could promote the standardisation of fetal femur measurements and resulting in a more reliable age estimates
Assessment of obstetric ultrasound images using machine learning
Full text linkUltrasound-based fetal biometry is used to derive important clinical information for identifying IUGR (intra-uterine growth restriction) and managing risk in pregnancy. Accurate and reproducible biometric measurement relies heavily on a good standard image plane. However, qualitative visual assessment, which includes the visual identification of certain anatomical landmarks in the image is prone to inter- and intra-reviewer variability and is also time-consuming to perform. Automated anatomical structure detection is the first step towards the development of a fast and reproducible quality assessment of fetal biometry images. This thesis deals specifically with abdominal scans in the development and evaluation of methods to automatically detect the stomach and the umbilical vein within them.First, an original method for detecting the stomach and the umbilical vein in fetal abdominal scans was developed using a machine learning framework. A classifier solution was designed with AdaBoost learning algorithm with Haar features extracted from the intensity image. The performance of the new method was compared on different clinically relevant gestational age groups.Speckle and the low contrast nature of ultrasound images motivated the idea of introducing features extracted from local phase images. Local phase is contrast invariant and has proven to be useful in other ultrasound image analysis application compared with intensity. Nevertheless, it has never been implemented in a machine learning environment before. In our second experiment, local phase features were proven to have higher discriminative power than intensity features which enabled them to be selected as the first weak classifiers with large classifier weight.Third, a novel approach to improving the speed of the detection was developed using a global feature symmetry map based on local phase to select the candidate locations for the stomach and the umbilical vein. It was coupled with a local intensity-based classifier to form a “hybrid” detector. A nine-fold increase in the average computational speed was recorded along with higher accuracy in the detection of both the anatomical structures.Quantitative and qualitative evaluations of all the algorithms were presented using 2384 fetal abdominal images retrieved from the image database study of the Oxford Ultrasound Quality Control Unit of the INTERGROWTH-21st project.Finally, the “hybrid” detection method was evaluated in two potential application scenarios. The first application was clinical scoring in which both the computer algorithm and four experts were asked to record presence or absence of the stomach and the umbilical vein in 400 ultrasound images. The computer-experts agreement was found to be comparable with the inter-expert agreement. The second application concerned selecting the standard image plane from 3D abdominal ultrasound volume. The algorithm was successful in selecting 93.36% of the images plane defined by the expert in 30 ultrasound volumes
COMPARISON OF MORPHOLOGICAL-BASED SEGMENTATION METHODS FOR FETAL FEMUR LENGTH MEASUREMENTS
No full textMeasurement of fetal femur length is crucial for the estimation of fetal age and growth pattern. Due to the noisy nature of ultrasound images and the variation in image acquisition and measurement techniques, manual measurements are subject to interobserver and intraobserver variability. The motivation of this paper is to study the efficiency of automated methods used in the femur endpoint detection module of our proposed computer-assisted processing and analysis system, which is employed to determine the gestational age for promoting the standardization of fetal femur measurements, thus resulting in more reliable age estimates. The proposed methods are based on the morphological operators methods(5) and the morphological watershed segmentation method. We applied these methods on a set of 100 digitized fetal femur images of size 287 x 224 pixels with 256 gray-level images and a resolution of 100 pixels per inch (ppi) horizontally and vertically. The results showed that the watershed method was the more efficient one and gave reliable results for every femur image tested
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
The Impact of Islamic Religious Education on the Development of Early Childhood Religious and Moral Values During the COVID-19 Pandemic in Indonesia and Malaysia
No full textWhen the world is busy with the COVID-19 virus outbreak, various sectors experienced a significant impact, especially in the education sector, which requires children to carry out learning activities from home. This study aims to determine the effect of Islamic religious education on early childhood\u27s religious and moral values during the COVID-19 pandemic. This study uses a quantitative analysis method of product-moment correlation through a t-test to test the significance of the effect of the independent variable on the dependent variable. The study results found that the hypothesis using the t-test showed that the independent variable of Islamic religious education was proven to significantly influence the dependent variable on the development of religious and moral values of early childhood. Then through the t-test, it can be seen that the significance value of 0.534 is greater than the 0.05 significance level. Thus, Ha is accepted, religious education has a significant effect on the development of religious and moral values of early childhood during the COVID-19 pandemic. This study contributes to a deep understanding that Islamic religious education affects the development of religious and moral values of early childhood even in the Covid-19 pandemic situation. The role of parents is a good role model for children to apply religious and moral values through Islamic religious education
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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