1,720,981 research outputs found
Effects of the series length on Lempel-Ziv Complexity during sleep
No full textLempel-Ziv Complexity (LZC) has been demonstrated to be a powerful complexity measure in several biomedical applications. During sleep, it is still not clear how many samples are required to ensure robustness of its estimate when computed on beat-to-beat interval series (RR). The aims of this study were: i) evaluation of the number of necessary samples in different sleep stages for a reliable estimation of LZC; ii) evaluation of the LZC when considering intersubject variability; and iii) comparison between LZC and Sample Entropy (SampEn). Both synthetic and real data were employed. In particular, synthetic RR signals were generated by means of AR models fitted on real data.
The minimum number of samples required by LZC for having no changes in its average value, for both NREM and REM sleep periods, was 104 (p1000 when a tolerance of 5% is considered satisfying.
The influence of the inter-subject variability on the LZC was first assessed on model generated data confirming what found (>104; p<0.01) for both NREM and REM stage. However, on real data, without differentiate between sleep stages, the minimum number of samples required was 1.8104.
The linear correlation between LZC and SampEn was computed on a synthetic dataset. We obtained a correlation higher than 0.75 (p<0.01) when considering sleep stages separately, and higher than 0.90 (p<0.01) when stages were not differentiated.
Summarizing, we suggest to use LZC with the binary quantization and at least 1000 samples when a variation smaller than 5% is considered satisfying, or at least 104 for maximal accuracy. The use of more than 2 levels of quantization is not recommended
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
A questionnaire study of the prevalence of childhood malnutrition in the Narayanganj area in Bangladesh
No full textA relative or absolute shortage of one or more nutrients results in malnutrition. It is a major public health concern for children under ten in low-income countries. A state of nutritional deficiency caused by inadequate protein or calorie intake is known as malnutrition. Children in developing countries frequently suffer from primary acute malnutrition as a result of insufficient food supplies brought on by social, economic, and environmental factors. From November to December 2024, a self-designed descriptive questionnaire study was carried out in the Narayanganj region of Bangladesh. The study included all relevant the study included all relevant information from their parents about their children aged one to ten years who had malnutrition-related problems. At most 62.6% of the children were from rural areas, whereas 37.1% were from town areas and 52.6% of parents were educated according to their interpretation. Analyzing the children's weight revealed that, 49 of them are underweight, 139 have a suitable body mass index, and 22 are heavyweight, with a body mass index greater than 48.6% of children were in excellent physical condition and were in good health. While 40.0% of the children had ordinary health, 7.6% had the worst physical state with minimal clinical characteristics, and eight instances had no apparent cause. On the other hand, diarrhea and decreased appetite are the most common issues, reported by 131 respondents overall. Finally, stronger preventive measures and greater community awareness can lessen malnutrition intensity and prevalence in that area of Bangladesh
High Resolution Digital Surface Model (DSM) to Support Modelling of Urban Flooding
Full text linkThis research work focuses on the generation of a high resolution digital surface model featuring complex urban surface characteristics in order to enrich the database for runoff simulations of urban drainage systems. The discussion of global climate change and its possible consequences have taken centre stage over the last decade. Global climate change has triggered more erratic weather patterns by causing severe and unpredictable rainfall events in many parts of the world. The incidence of more frequent rainfall has led to the problem of increased flooding in urban areas. The increased property values of urban structures and threats to people's personal safety have hastened the demand for a detailed urban drainage simulation model for accurate flood prediction. Although the use of 2D hydraulic modelling approach in rural floodplains is in practice for quite a long time, the use of the same approach in urban floodplains is still in its infancy. The reason is mainly due to the lack of a high resolution topographic model describing urban surface characteristics properly.
High resolution surface data describing hydrologic and hydraulic properties of complex urban areas are the prerequisite to more accurately describing and simulating the flood water movement and thereby taking adequate measures against urban flooding. Airborne LiDAR (Light detection and ranging) is an efficient way of generating a high resolution Digital Surface Model (DSM) of any study area. The processing of high-density and large volume of unstructured LiDAR data is a difficult and time-consuming task towards generating fine resolution spatial databases when considering only human intervention. The application of robust algorithms in terms of processing this massive volume of data can significantly reduce the data processing time and thereby increase the degree of automation as well as accuracy.
This research work presents a number of techniques pertaining to processing, filtering and classification of LiDAR point data in order to achieve higher degree of automation and accuracy towards generating a high resolution urban surface model. This research work also describes the use of ancillary datasets such as aerial images and topographic maps in combination with LiDAR data for feature detection and surface characterization. The integration of various data sources facilitates detailed modelling of street networks and accurate detection of various urban surface types (e.g. grasslands, bare soil and impervious surfaces).
While the accurate characterization of various surface types contributes to the better modelling of rainfall runoff processes, the application of LiDAR-derived fine resolution DSM serves as input to 2D hydraulic models and capable of simulating surface flooding scenarios in cases the sewer systems are surcharged.
Thus, this research work develops high resolution spatial databases aiming at improving the accuracy of hydrologic and hydraulic databases of urban drainage systems. Later, these databases are given as input to a standard flood simulation software in order to: 1) test the suitability of the databases for running the simulation; 2) assess the performance of the hydraulic capacity of urban drainage systems and 3) predict and visualize the surface flooding scenarios in order to take necessary flood protection measures
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
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