145 research outputs found

    Computer Vision Control for Phased Array Beam Steering

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    This work proves a concept for a wireless access point that uses image identification and tracking algorithms to automate the electronic control of a phased antenna array. Phased arrays change the direction of their radiation electronically by adjusting the phase of the signal applied to the individual antenna elements of the array. This ability can improve a user’s connectivity to a wireless network by directing radiation from an access point to a user, provided that the user’s location is known. Open source image processing and machine learning libraries provided a basis for developing a Python program that determines the position of a target using a single camera. This program uses the position information acquired from the camera to calculate the phases required to steer the radiation of the array to the target. The Python program sends the required phases to another piece of software that controls the phases of the phased array. This software adjusts the phases of the antenna elements and steers the main beam. Experiments were conducted to evaluate the identification, tracking, and control capabilities of the system. Finally, a full system demonstration was performed to benchmark the wireless performance, study the trade-offs in performance for complexity, and compare the connectivity to the current standard in multi-antenna access points

    Comparison of performance of F1 Romanov crossbred ewes with wool and hair breeds during fall lambing and body weight and longevity through six production years

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    The objective of this study was to evaluate wool (Dorset and Rambouillet) and hair (Dorper, Katahdin, and White Dorper) breeds for their ability to complement Romanov germplasm in an annual fall lambing system by estimating direct maternal grandsire and sire breed effects on economically important lamb and ewe traits. After 3 yr of evaluation under spring lambing, ewes of the five F1 types were transitioned to spring mating, exposed to composite terminal sires, and evaluated under a barn lambing system at 4, 5, and 6 yr of age. A total of 527 first generation crossbred (F1) ewes produced 1,151 litters and 2,248 lambs from 1,378 May exposures. After accounting for differences in dam age, birth type, and sex, lamb survival to weaning was unaffected by maternal grandsire breed (P = 0.30). However, lambs born to 50% Dorset (16.8 ± 0.21 kg) or 50% White Dorper ewes (16.8 ± 0.28 kg) were heavier at weaning than those born to 50% Katahdin dams (13.8 ± 0.32 kg; P \u3c 0.001). Additionally, lambs born to 50% Dorset ewes were heavier than those born to 50% Rambouillet (16.0 ± 0.22 kg) and 50% Dorper ewes (15.7 ± 0.33; P ≤ 0.03), but no other pairwise maternal grandsire breed differences were observed (P ≥ 0.06). Ewe body weight (n = 3,629) was recorded prior to each of six possible mating seasons and, across ages, was greatest for Dorset- and Rambouillet-sired ewes (56.7 ± 0.44 and 56.5 ± 0.45 kg, respectively), intermediate for Dorper- and White Dorper-sired ewes (54.7 ± 0.78 and 54.1 ± 0.64 kg, respectively), and least for Katahdin-sired ewes (51.5 ± 0.45 kg). Fertility after spring mating (0.80 ± 0.03 to 0.87 ± 0.02), litter size at birth (1.46 ± 0.09 to 1.71 ± 0.07), and litter size at weaning (1.25 ± 0.06 to 1.46 ± 0.06) were not impacted by sire breed (P ≥ 0.16). Ewe longevity, assessed as the probability of being present after 6 production years, was also not affected by sire breed (0.39 ± 0.03 to 0.47 ± 0.03; P = 0.44). Rambouillet-sired ewes weaned more total weight of lamb (21.5 ± 0.94 kg) than Katahdin-sired ewes (17.8 ± 0.94 kg; P = 0.05), but no other sire breed differences were detected (P ≥ 0.07). Results demonstrated that incorporating the Romanov into a crossbreeding system is a practical means of improving out-of-season ewe productivity

    Computer Vision Control for Phased Array Beam Steering

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    This work proves a concept for a wireless access point that uses image identification and tracking algorithms to automate the electronic control of a phased antenna array. Phased arrays change the direction of their radiation electronically by adjusting the phase of the signal applied to the individual antenna elements of the array. This ability can improve a user’s connectivity to a wireless network by directing radiation from an access point to a user, provided that the user’s location is known. Open source image processing and machine learning libraries provided a basis for developing a Python program that determines the position of a target using a single camera. This program uses the position information acquired from the camera to calculate the phases required to steer the radiation of the array to the target. The Python program sends the required phases to another piece of software that controls the phases of the phased array. This software adjusts the phases of the antenna elements and steers the main beam. Experiments were conducted to evaluate the identification, tracking, and control capabilities of the system. Finally, a full system demonstration was performed to benchmark the wireless performance, study the trade-offs in performance for complexity, and compare the connectivity to the current standard in multi-antenna access points

    Relationship of Relative Calving Date of Beef Heifers to Production Efficiency and Subsequent Reproductive Performance

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    Relative date of first calving of beef heifers was studied in relation to production efficiency and subsequent reproductive performance. Crossbred heifers were managed in drylot for 1 year, providing for measurement of feed intake through weaning of the first calf. Production traits were evaluated by calving group (CG), where CG1 included records of heifers calving (and calves born) in the first 21 days of the calving season for a particular year, CG2 included those calving from 22 through 42 days and CG3 included those calving after 42 days. Calving groups did not differ significantly for preweaning calf average daily gain, while weaning age differences resulted in heavier weaning weights for CG1 compared to CG2 and CG3. Earlier relative calving date was associated with increased cumulative feed energy intake of heifers and their calves during the 1 -year test period. In terms of production efficiency, the weaning weight advantage of earlier calving was only partly offset by increased feed energy intake of the dam-calf unit, resulting in .9 Mcal metabolizable energy (ME) less per Ib calf weaning weight for CG1 vs CG2 and 2.9 Mcal ME less per Ib calf weaning weight for CG1 vs CG3 for the 1-year period. Results suggested that within a limited calving season, earlier calving dams tended to be biologically and economically more efficient, apparently at least in part because a greater proportion of an annual production cycle consisted of a productive (lactating) mode, diluting maintenance costs as a fraction of all costs. Heifers in CG1 tended to calve earlier than CG3 heifers for the second calf. Calving interval was a biased measure under the management conditions of a limited breeding season and culling of open cows

    Learning and predicting time series by neural networks

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    Artificial neural networks which are trained on a time series are supposed to achieve two abilities: firstly to predict the series many time steps ahead and secondly to learn the rule which has produced the series. It is shown that prediction and learning are not necessarily related to each other. Chaotic sequences can be learned but not predicted while quasiperiodic sequences can be well predicted but not learned.Comment: 5 page

    Glucosamine supplementation during late gestation alters placental development and increases litter size

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    Background: During late gestation the placental epithelial interface becomes highly folded, which involves changes in stromal hyaluronan. Hyaluronan is composed of glucoronate and N-acetyl-glucosamine. We hypothesized that supplementing gestating dams with glucosamine during this time would support placental folded-epithelial-bilayer development and increase litter size. In Exp. 1, gilts were unilaterally hysterectomizedovariectomized (UHO). UHO gilts were mated and then supplemented daily with 10 g glucosamine (n = 16) or glucose (control, n = 17) from d 85 of gestation until slaughter (d 105). At slaughter, the number of live fetuses was recorded and each live fetus and its placenta was weighed. Uterine wall samples adjacent to the largest and smallest fetuses within each litter were processed for histology. In Exp. 2, pregnant sows in a commercial sow farm were supplemented with either 10 g glucosamine or glucose daily from d 85 of gestation to farrowing. Total piglets born and born alive were recorded for each litter. In Exp. 3, the same commercial farm and same protocol were used except that the dose of glucosamine and glucose was doubled to 20 g/d. Results: In Exp. 1, the number of live fetuses tended to be greater in glucosamine-treated UHO gilts (P = 0.098). Placental morphometry indicated that the width of the folded bilayer was greater (P = 0.05) in glucosamine-treated gilts. In Exp. 2, litter size did not differ between glucosamine- and glucose-treated sows. However in Exp. 3, the increased dose of glucosamine resulted in a significant treatment by parity interaction (P ≤ 0.01), in which total piglets born and born alive were greater in glucosamine treated sows of later parity (5 and 6). Conclusions: These results indicated that glucosamine supplementation increased the width of the folds of the placental bilayer and increased litter size in later parity, intact pregnant commercial sows

    Association of Porcine Heparanase and Hyaluronidase 1 and 2 with Reproductive and Production Traits in a Landrace–Duroc–Yorkshire Population

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    The ovary and placenta are dynamic structures requiring constant modification both structurally and through cell–cell communication capabilities. The extracellular matrix and basement membranes are primarily composed of a milieu of glycosaminoglycans, including heparan sulfate and hyaluronan. Heparanase (HPSE) and hyaluronidases (HYAL) are responsible for degrading heparan sulfate and hyaluronan, respectively. Therefore, the objective of this study was to evaluate the relationship of SNPs distinct to HPSE, HYAL1, and HYAL2 with measurements of reproduction and production traits in swine. Single trait associations were performed on a Landrace–Duroc–Yorkshire population using SNPs discovered and identified in HPSE, HYAL1, and HYAL2. Analyses were conducted on an extended pedigree and SNPs were found to be associated with reproductive and production traits. Prior to multiple-testing corrections, SNPs within HPSE were weakly associated (P < 0.03) having additive effects with age at puberty (−2.5 ± 1.08 days), ovulation rate (0.5 ± 0.24 corpora lutea), and number of piglets born alive (0.9 ± 0.44 piglets). A HYAL1 and two HYAL2 SNP were nominally associated (P ≤ 0.0063) with number of piglets born alive after multiple-testing corrections (effects between 1.02 and 1.44 piglets), while one of the same HYAL2 markers maintained a modest association (P = 0.0043) having a dominant effect with number of piglets weaned (1.2 ± 0.41 piglets) after multiple-testing correction. Functionally, HPSE and HYAL1 and 2 have been shown to participate in events related to ovarian and placental activity. SNPs from these studies could potentially assist with understanding genetic components underlying sow lifetime productivity as measured by piglet survivability based on number born alive and number weaned, thereby contributing to a greater number of pigs/sow/year
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