367 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

    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

    Minority Game of price promotions in fast moving consumer goods markets

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    A variation of the Minority Game has been applied to study the timing of promotional actions at retailers in the fast moving consumer goods market. The underlying hypotheses for this work are that price promotions are more effective when fewer than average competitors do a promotion, and that a promotion strategy can be based on past sales data. The first assumption has been checked by analysing 1467 promotional actions for three products on the Dutch market (ketchup, mayonnaise and curry sauce) over a 120-week period, both on an aggregated level and on retailer chain level. The second assumption was tested by analysing past sales data with the Minority Game. This revealed that high or low competitor promotional pressure for actual ketchup, mayonnaise, curry sauce and barbecue sauce markets is to some extent predictable up to a forecast of some 10 weeks. Whereas a random guess would be right 50% of the time, a single-agent game can predict the market with a success rate of 56% for a 6 to 9 week forecast. This number is the same for all four mentioned fast moving consumer markets. For a multi-agent game a larger variability in the success rate is obtained, but predictability can be as high as 65%. Contrary to expectation, the actual market does the opposite of what game theory would predict. This points at a systematic oscillation in the market. Even though this result is not fully understood, merely observing that this trend is present in the data could lead to exploitable trading benefits. As a check, random history strings were generated from which the statistical variation in the game prediction was studied. This shows that the odds are 1:1,000,000 that the observed pattern in the market is based on coincidence.Comment: 19 pages, 10 figures, accepted for publication in Physica

    Parent and Community Involvement in Schools

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    This school improvement plan at Carlisle Elementary focuses on enhancing parent and community involvement through structured strategies and collaborative efforts. Despite the existing engagement frameworks, the school recognizes the need for more effective integration of caregivers and local stakeholders in educational processes. The plan proposes forming committees, increasing communication, providing inclusive training sessions, and fostering an environment that respects diverse backgrounds. Utilizing the Positive Behavior Intervention System (PBIS) and Tiered Fidelity Inventory (TFI), the project aims to systematically improve family and community participation. Initial data suggest areas such as household communication and caregiver training need significant enhancement. The anticipated implementation spans the 2024-2025 academic year with continuous evaluation to adapt strategies for maximum effectiveness. The initiative promises to bridge the gap between school activities and community involvement, potentially leading to improved educational outcomes and stronger societal bonds

    Relationship of Sire Expected Progeny Differences to Maternal Performance of First-Calf Daughters in a Commercial Herd

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    Maternal performance for first calf production was evaluated in retrospect for daughters whose sires had expected progeny differences (EPDs) available from 1988 beef breed association national genetic evaluation summaries. When grouped into high EPD and low EPD groups, sire EPD group averages for actual daughter milk production and weaning weights of daughters\u27 off spring consistently ranked the same as sire group average EPDs for milk and maternal weaning weight, although differences between groups were not statistically significant

    Interrelationships of Heifer Milk Production and Other Biological Traits with Production Efficiency to Weaning

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    Interrelationships among milk production, cow-calf feed efficiency and other biological traits were evaluated on first-calf females and their calves. Production efficiency was defined as cumulative feed metabolizable energy consumed by the dam-calf pair during the year divided by calf weaning weight. Results indicated that increased levels of milk production were associated with improved production efficiency to weaning as long as calves have the genetic potential to convert the extra milk into body weight gains. However, the incremental improvement in efficiency per unit of increased milk was less for each additional unit of milk

    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
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