32,788 research outputs found

    A Feasibility Study on the Use of a Structured Light Depth-Camera for Three-Dimensional Body Measurements of Dairy Cows in Free-Stall Barns

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    Frequent checks on livestock\u2019s body growth can help reducing problems related to cow infertility or other welfare implications, and recognizing health\u2019s anomalies. In the last ten years, optical methods have been proposed to extract information on various parameters while avoiding direct contact with animals\u2019 body, generally causes stress. This research aims to evaluate a new monitoring system, which is suitable to frequently check calves and cow\u2019s growth through a three-dimensional analysis of their bodies\u2019 portions. The innovative system is based on multiple acquisitions from a low cost Structured Light Depth-Camera (Microsoft Kinect\u2122 v1). The metrological performance of the instrument is proved through an uncertainty analysis and a proper calibration procedure. The paper reports application of the depth camera for extraction of different body parameters. Expanded uncertainty ranging between 3 and 15 mm is reported in the case of ten repeated measurements. Coef\ufb01cients of determination R2> 0.84 and deviations lower than 6% from manual measurements where in general detected in the case of head size, hips distance, withers to tail length, chest girth, hips, and withers height. Conversely, lower performances where recognized in the case of animal depth (R2 = 0.74) and back slope (R2 = 0.12)

    Optimising cow traffic in automatic milking systems

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    This thesis comprises the results from three separate studies performed in the experimental automatic milking system at Kungsängen Research Centre, Swedish University of Agricultural Sciences, Uppsala, Sweden. In the first study, 30 high-yielding cows in early lactation were subjected to two different degrees of controlled cow traffic, and the effects on milk yield, dry matter intake, feeding patterns and voluntary visits to the milking unit and the control gates were measured. A model of mixed distributions for estimations of biologically relevant meal criteria from registrations in roughage stations was also evaluated. In the second study, the behaviour of 24 cows after they had been redirected in control gates was observed, and the cause of long redirection times from gates until they showed up in the milking unit was examined. In the third study, 9 cows were subjected to three different cow traffic systems in a carry-over design and the effects on cortisol concentrations in milk and ruminating patterns were studied. The studies showed that milking frequency and thereby milk production can be altered by different time settings in the control gates without limiting the daily feed intake of the cows. A high degree of guidance provokes social effects in the queue in front of the milking unit and in the feeding areas. It also makes it difficult for the cows to follow their natural feeding patterns. Judging from measurements of milk cortisol concentrations, controlled cow traffic was not stressful for the cows. Cows initiated meals with short intervals, which offered many opportunities to milk them. But the queue in front of the milking unit caused long redirection times, and the control gates failed to guide cows to high milking frequencies. Individual differences in feeding patterns and how cows respond to redirections in the control gates suggest that the control gates should be making decisions on an individual level

    An investigation into the behaviour of air rifle pellets in ballistic gel and their interaction with bone

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    Although air weapons are considerably lower in power than other firearms, there is increasing concern that serious injuries can result from their misuse. The present study was therefore carried out to improve understanding of the terminal ballistic behaviour of air rifle pellets. Pellets were fired into ballistic gel under a variety of conditions. The pellets penetrated further than anticipated from their low cross-sectional density, and Bloom number was not necessarily a good guide to gel behaviour. Pellet penetration into the gel decreased with increasing gel concentration, and appeared to be linear at higher concentrations. Pointed pellets penetrated up to 50% further than rounded pellets. Power and range affect penetration, but other factors are also important, and power alone is not a simple guide to potential penetration. Test firings were also carried out firing pellets into ballistic gel that contained sections of animal bone. Computed tomography (CT) and visual observation were employed to record the interactions. CT scanning showed potential as a tool for examining pellet damage. The bone appeared to be undamaged, but the pellets were severely deformed on impact. If the pellet strikes the bone at an angle, less energy is absorbed by the impact and the pellet fragments may ricochet and cause further damage in the gel. A tentative model is proposed for estimating the energy absorbed by the impact

    Morphological re-description and molecular identification of Tabanidae (Diptera) in East Africa

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    Biting flies of the family Tabanidae are important vectors of human and animal diseases across continents. However, records of Africa tabanids are fragmentary and mostly cursory. To improve identification, documentation and description of Tabanidae in East Africa, a baseline survey for the identification and description of Tabanidae in three eastern African countries was conducted. Tabanids from various locations in Uganda (Wakiso District), Tanzania (Tarangire National Park) and Kenya (Shimba Hills National Reserve, Muhaka, Nguruman) were collected. In Uganda, octenol baited F-traps were used to target tabanids, while NG2G traps baited with cow urine and acetone were employed in Kenya and Tanzania. The tabanids were identified using morphological and molecular methods. Morphologically, five genera (Ancala, Tabanus, Atylotus, Chrysops and Haematopota) and fourteen species of the Tabanidae were identified. Among the 14 species identified, six belonged to the genus Tabanus of which two (T. donaldsoni and T. guineensis) had not been described before in East Africa. The greatest diversity of tabanid species were collected from the Shimba Hills National Reserve, while collections from Uganda (around the shores of Lake Victoria) had the fewest number of species. However, the Ancala genus was found in Uganda, but not in Kenya or Tanzania. Maximum likelihood phylogenies of mitochondrial cytochrome c oxidase 1 (COI) genes sequenced in this study show definite concordance with morphological species identifications, except for Atylotus. This survey will be critical to building a complete checklist of Tabanidae prevalent in the region, expanding knowledge of these important vectors of human and animal diseases

    A tackle box guide to: common saltwater fishes of southwest Florida

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    There are well over 150 species of fish caught by hook and line in local waters. The 86 species included in this book were selected by the author and editors because they are the most frequently encountered. For eachspecies, important informationabout distinguishing features, biology/habitat, and fishing methods is provided. The often confusing common nicknames applied to each fish are noted, as well as the fish's preferred common name. (56pp.

    Strategies for Representing Tone in African Writing Systems

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    Tone languages provide some interesting challenges for the designers of new orthographies. One approach is to omit tone marks, just as stress is not marked in English (zero marking). Another approach is to do phonemic tone analysis and then make heavy use of diacritic symbols to distinguish the `tonemes' (exhaustive marking). While orthographies based on either system have been successful, this may be thanks to our ability to manage inadequate orthographies rather than to any intrinsic advantage which is afforded by one or the other approach. In many cases, practical experience with both kinds of orthography in sub-Saharan Africa has shown that people have not been able to attain the level of reading and writing fluency that we know to be possible for the orthographies of non-tonal languages. In some cases this can be attributed to a sociolinguistic setting which does not favour vernacular literacy. In other cases, the orthography itself might be to blame. If the orthography of a tone language is difficult to user or to learn, then a good part of the reason, I believe, is that the designer either has not paid enough attention to the function of tone in the language, or has not ensured that the information encoded in the orthography is accessible to the ordinary (non-linguist) user of the language. If the writing of tone is not going to continue to be a stumbling block to literacy efforts, then a fresh approach to tone orthography is required, one which assigns high priority to these two factors. This article describes the problems with orthographies that use too few or too many tone marks, and critically evaluates a wide range of creative intermediate solutions. I review the contributions made by phonology and reading theory, and provide some broad methodological principles to guide someone who is seeking to represent tone in a writing system. The tone orthographies of several languages from sub-Saharan Africa are presented throughout the article, with particular emphasis on some tone languages of Cameroon

    'Part'ly first among equals: Semantic part-based benchmarking for state-of-the-art object recognition systems

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    An examination of object recognition challenge leaderboards (ILSVRC, PASCAL-VOC) reveals that the top-performing classifiers typically exhibit small differences amongst themselves in terms of error rate/mAP. To better differentiate the top performers, additional criteria are required. Moreover, the (test) images, on which the performance scores are based, predominantly contain fully visible objects. Therefore, `harder' test images, mimicking the challenging conditions (e.g. occlusion) in which humans routinely recognize objects, need to be utilized for benchmarking. To address the concerns mentioned above, we make two contributions. First, we systematically vary the level of local object-part content, global detail and spatial context in images from PASCAL VOC 2010 to create a new benchmarking dataset dubbed PPSS-12. Second, we propose an object-part based benchmarking procedure which quantifies classifiers' robustness to a range of visibility and contextual settings. The benchmarking procedure relies on a semantic similarity measure that naturally addresses potential semantic granularity differences between the category labels in training and test datasets, thus eliminating manual mapping. We use our procedure on the PPSS-12 dataset to benchmark top-performing classifiers trained on the ILSVRC-2012 dataset. Our results show that the proposed benchmarking procedure enables additional differentiation among state-of-the-art object classifiers in terms of their ability to handle missing content and insufficient object detail. Given this capability for additional differentiation, our approach can potentially supplement existing benchmarking procedures used in object recognition challenge leaderboards.Comment: Extended version of our ACCV-2016 paper. Author formatting modifie
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