1,720,974 research outputs found
Fish tracking using detection in aquaculture : a pilot study
Full text linkUse two different detection models and combine them with a tracking algorithm to be able to track fish that can be used in further fish welfare applications.M-TD
Computer vision for fish monitoring : challenges and possibilities
Full text linkThis master's thesis focuses on the evaluation and exploration of detection and tracking algorithms for fish in a dense underwater environment. The primary objectives were to achieve precise and accurate fish detection and to track fish over an extended period. The thesis explores the performance of two object detection algorithms, YOLOv4 and YOLOv8, as well as their integration with the DeepSORT tracking algorithm. The algorithms were trained and evaluated using a dataset collected from a densely populated underwater fish tank. The dataset was manually annotated using bounding box annotation techniques to accurately label the objects of interest.
The results demonstrated the effectiveness of both YOLOv4 and YOLOv8 in detecting fish in densely populated environments. However, YOLOv8 achieved a significantly higher mAP50-95 score, indicating better localization and detection accuracy. It proved more adept at precisely locating the position of detected fish, leading to improved overall detection performance.
In terms of fish tracking the combination of DeepSORT and YOLOv8 showed the best overall performance, as evidenced by higher MOTA and IDF1 scores, and lower MOTP scores. However, tracking individual fish over extended periods presented challenges due to occlusions and rapid trajectory changes, leading to a high number of identity switches.
By evaluating and exploring the effectiveness of detection and tracking algorithms, this thesis contributes to the advancement of fish monitoring techniques in aquaculture. The findings provide valuable insights into the performance of YOLOv4 and YOLOv8 and the potential of DeepSORT for accurate and reliable fish detection and tracking. The results and methodologies presented in this study lay the groundwork for further research and development in the field, aiming to enhance fish welfare, optimize resource management, and improve efficiency in aquaculture practices.M-TD
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
Radar based central blood pressure estimation
No full textThis is a feasibility study in using radar for estimating blood pressure and which could allow for continuous, non-invasive measurements both inside and outside the clinic. Blood pressure has extensive use in emergency care for monitoring the state of a patient, in detection and treatment of hypertension as an important factor of cardiovascular diseases, in emerging applications and more. The invasive cannula for central, continuous, measurements and the sphygmomanometer for peripheral, punctual measurements are currently the reference tools for measuring blood pressure in the operating room and in the physician’s office respectively. However, new blood pressure estimation devices could increase mobility in the hospital and reduce white-coat hypertension in the office. Moreover, such accessible and low-cost devices could extend measurements outside the clinic.
The main work was focused on the estimation of the time-varying aortic radius as a prerequisite for the estimation of blood pressure. This work was conducted primarily based on theoretic considerations and simulations using realistic models of the human thorax. In addition, one article analyzed radar signatures from a phantom model and from an in vivo experiment to test findings. Radar echoes were analyzed for information regarding changes in the aorta radius. A magnetic resonance imaging study was conducted to map tissue movements as an aid to radar analysis.
Theoretical considerations proposed an optimal frequency band for aorta radius estimation. Given sufficient dynamic range in the radar system, and shown in both simulations and measurements on a phantom model, interference phenomena determined radius estimation success. In the optimistic scenario, radius changes could be estimated. In the more realistic scenario, only a proxy on aorta radius could be tracked. The magnetic resonance imaging study identified a mechanical coupling between the aorta and the heart which would complicate radius estimation. Despite this coupling, the study confirmed findings in the literature that aorta radius is related to pressure. The in vivo experiment showed evidence of an echo from the aorta, however the study did not find evidence of two distinct reflectors.
Although successful in identifying a signature from the aorta, the mechanical coupling between the heart and the aorta implies that this signature contains information on both location and radius. Because two distinct echoes could not be identified, direct estimates of radius was not considered feasible. An indirect approach based on blood pressure propagation speed may still be possible, although the coupling would need to be compensated for. As a feasibility study, certain simplifications were imposed and in particular the effects of respiration were disregarded
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
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