319 research outputs found

    Connected Component Algorithm for Gestures Recognition

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    This paper presents head and hand gestures recognition system for Human Computer Interaction (HCI). Head and Hand gestures are an important modality for human computer interaction. Vision based recognition system can give computers the capability of understanding and responding to the hand and head gestures. The aim of this paper is the proposal of real time vision system for its application within a multimedia interaction environment. This recognition system consists of four modules, i.e. capturing the image, image extraction, pattern matching and command determination. If hand and head gestures are shown in front of the camera, hardware will perform respective action. Gestures are matched with the stored database of gestures using pattern matching. Corresponding to matched gesture, the hardware is moved in left, right, forward and backward directions. An algorithm for optimizing connected component in gesture recognition is proposed, which makes use of segmentation in two images. Connected component algorithm scans an image and group its pixels into component based on pixel connectivity i.e. all pixels in connected component share similar pixel intensity values and are in some way connected with each other. Once all groups have been determined, each pixel is labeled with a color according to component it was assigned to

    Development and evaluation of an automated spray patternator using digital liquid level sensors

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    Citation: Luck, J. D., Schaardt, W. A., Forney, S. H., & Sharda, A. (2016). Development and evaluation of an automated spray patternator using digital liquid level sensors. Applied Engineering in Agriculture, 32(1), 47-52. doi:10.13031/aea.32.11381The purpose of this study was to develop and evaluate an automated spray pattern measurement system which utilized digital liquid level sensors to quantify the coefficient of variation (CV) for different nozzle configurations. The overall system was designed to measure nozzle effluent in 25 mm divisions from 38.1 to 76.2 cm in width for multiple nozzle configurations with a total patternator surface width of 3.05 m. The patternator surface and data collection system were designed and developed to achieve three primary goals: patternator surface division accuracy, data collection system accuracy, and data collection system repeatability. Patternator surface measurements indicated an average standard deviation of approximately 0.1 mm (0.4%) which would not contribute significantly to spray pattern CV estimates. To quantify the measurement accuracy, the automated system was compared to manual data collection using weights collected from graduated cylinders. Statistical analysis revealed no difference (p > 0.05) between CV estimates from the manual and automated data collection methods. The average difference in CV between the two methods was 0.15% which considered 12 tests per method. Repeatability was also a primary concern, the standard deviation among CV values for tests conducted with the automated system was only 0.35%. The evaluation of the system provided confidence that suitable results would be acquired for different nozzle configurations consisting of acceptable or relatively poor spray patterns. © 2016 American Society of Agricultural and Biological Engineers

    A Case Study Concerning The Effects Of Controller Response And Turning Movements On Application Rate Uniformity With A Self-Propelled Sprayer

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    The use of precision agriculture technologies such as automatic boom section control allows producers to reduce off-target application when applying herbicides. While automatic boom section control provides benefits, pressure differences across the spray boom resulting from boom section actuation may lead to off-rate application errors. Off-rate errors may also result from spray rate controller compensation for ground speed changes or velocity variation across the spray boom during turning movements. This project focused on characterizing application rate variation for three fields located in central Kentucky. GPS coordinates, boom control status, and nozzle pressure data (at 15 nozzle locations) were recorded as the sprayer traversed the study fields. Control section coverage areas and nozzle flow rates (calculated from the nozzle pressure with manufacturer calibration data) were used to estimate application rates. Results indicated the majority of each field received application rates at or below the target rate, as only 25% to 36% of the area in the study fields received application rates within the target rate ±10%. Spray rate controller lag time appeared to contribute to lower application rates as the sprayer accelerated and higher application rates as the sprayer decelerated as the controller attempted to compensate for changes in sprayer velocity. In addition, as boom control sections were turned off, pressure increases in the remaining sections resulted in higher application rates. Conversely, as boom sections were turned on, spray rate controller lag time may have contributed to lower application rates. Estimated application rate maps were also generated from the data to allow for a visual summary of the potential errors

    Huge field-effect surface charge injection and conductance modulation in metallic thin films by electrochemical gating

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    The field-effect technique, popular thanks to its application in common field-effect transistors, is here applied to metallic thin films by using as a dielectric a novel polymer electrolyte solution. The maximum injected surface charge, determined by a suitable modification of a classic method of electrochemistry called double-step chronocoulometry, reached more than 4 × 10 15 charges/cm 2 . At room temperature, relative variations of resistance up to 8%, 1.9% and 1.6% were observed in the case of gold, silver and copper, respectively and, if the films are thick enough (≥25 nm), results can be nicely explained within a free-electron model with parallel resistive channels. The huge charge injections achieved make this particular field-effect technique very promising for a vast variety of materials such as unconventional superconductors, graphene and 2D-like materials. © 2012 Elsevier B.V

    Temperature Dependence of Electric Transport in Few-layer Graphene under Large Charge Doping Induced by Electrochemical Gating

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    The temperature dependence of electric transport properties of single-layer and few-layer graphene at large charge doping is of great interest both for the study of the scattering processes dominating the conductivity at different temperatures and in view of the theoretically predicted possibility to reach the superconducting state in such extreme conditions. Here we present the results obtained in 3-, 4- and 5-layer graphene devices down to 3.5 K, where a large surface charge density up to about 6.8·1014 cm-2 has been reached by employing a novel polymer electrolyte solution for the electrochemical gating. In contrast with recent results obtained in single-layer graphene, the temperature dependence of the sheet resistance between 20 K and 280 K shows a low-temperature dominance of a T2 component - that can be associated with electron-electron scattering - and, at about 100 K, a crossover to the classic electron-phonon regime. Unexpectedly, this crossover does not show any dependence on the induced charge density, i.e. on the large tuning of the Fermi energy

    Temperature Dependence of Electric Transport in Few-layer Graphene under Large Charge Doping Induced by Electrochemical Gating

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    The temperature dependence of electric transport properties of single-layer and few-layer graphene at large charge doping is of great interest both for the study of the scattering processes dominating the conductivity at different temperatures and in view of the theoretically predicted possibility to reach the superconducting state in such extreme conditions. Here we present the results obtained in 3-, 4- and 5-layer graphene devices down to 3.5 K, where a large surface charge density up to about 6.8x10^14 cm^(-2) has been reached by employing a novel polymer electrolyte solution for the electrochemical gating. In contrast with recent results obtained in single-layer graphene, the temperature dependence of the sheet resistance between 20 K and 280 K shows a low-temperature dominance of a T^2 component - that can be associated with electron-electron scattering - and, at about 100 K, a crossover to the classic electron-phonon regime. Unexpectedly this crossover does not show any dependence on the induced charge density, i.e. on the large tuning of the Fermi energy.Comment: 13 pages, 6 color figure

    Early Prediction of Movie Box Office Success based on Wikipedia Activity Big Data

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    Use of socially generated "big data" to access information about collective states of the minds in human societies has become a new paradigm in the emerging field of computational social science. A natural application of this would be the prediction of the society's reaction to a new product in the sense of popularity and adoption rate. However, bridging the gap between "real time monitoring" and "early predicting" remains a big challenge. Here we report on an endeavor to build a minimalistic predictive model for the financial success of movies based on collective activity data of online users. We show that the popularity of a movie can be predicted much before its release by measuring and analyzing the activity level of editors and viewers of the corresponding entry to the movie in Wikipedia, the well-known online encyclopedia.Comment: 13 pages, Including Supporting Information, 7 Figures, Download the dataset from: http://wwm.phy.bme.hu/SupplementaryDataS1.zi

    Testing star formation laws in a starburst galaxy at redshift 3 resolved with ALMA

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    Using high-resolution (sub-kiloparsec scale) data obtained by ALMA, we analyse the star formation rate (SFR), gas content, and kinematics in SDP 81, a gravitationally lensed starburst galaxy at redshift 3. We estimate the SFR surface density (ΣSFR) in the brightest clump of this galaxy to be 357+135−85M⊙yr−1kpc−2, over an area of 0.07 ± 0.02 kpc2. Using the intensity-weighted velocity of CO (5–4), we measure the turbulent velocity dispersion in the plane of the sky and find σv, turb = 37 ± 5 km s−1 for the clump, in good agreement with previous estimates along the line of sight. Our measurements of the gas surface density, freefall time, and turbulent Mach number allow us to compare the theoretical SFR from various star formation models with that observed, revealing that the role of turbulence is crucial to explaining the observed SFR in this clump. While the Kennicutt–Schmidt (KS) relation predicts an SFR surface density of ΣSFR, KS = 52 ± 17 M⊙ yr−1 kpc−2, the single-freefall model by Krumholz, Dekel, and McKee (KDM) predicts ΣSFR, KDM = 106 ± 37 M⊙ yr−1 kpc−2. In contrast, the multifreefall (turbulence) model by Salim, Federrath, and Kewley (SFK) gives ΣSFR,SFK=491+139−194M⊙yr−1kpc−2. Although the SFK relation overestimates the SFR in this clump (possibly due to the negligence of magnetic fields), it provides the best prediction among the available models. Finally, we compare the star formation and gas properties of this galaxy to local star-forming regions and find that the SFK relation provides the best estimates of SFR in both local and high-redshift galaxies.PS acknowledges travel support from the International Programmes and Collaboration Division, Birla Institute of Technology and Science, Pilani, India.5 CF acknowledges funding provided by the Australian Research Council’s Discovery Projects (grants DP150104329 and DP170100603), the Australian National University Futures Scheme, and the Australia-Germany Joint Research Cooperation Scheme [Universities Australia-German Academic Exchange Service (DAAD)]. EdC gratefully acknowledges the Australian Research Council for funding support as the recipient of a Future Fellowship (FT150100079). SD is a Rutherford Fellow supported by the UK Science and Technology Facilities Council

    Explaining context, mechanism and outcome in adult community mental health crisis care: a realist evidence synthesis

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    Mental health crises cause significant distress and disruption to the lives of individuals and their families. Community crisis care systems are complex, often hard to navigate and poorly understood. This realist evidence synthesis aimed to explain how, for whom and in what circumstances community mental health crisis services for adults work to resolve crises and is reported according to RAMESES guidelines. Using realist methodology, initial programme theories were identified and then tested through iterative evidence searching across 10 electronic databases, four expert stakeholder consultations and n = 20 individual interviews. 45 relevant records informed the three initial programme theories, and 77 documents, were included in programme theory testing. 39 context, mechanism, outcome configurations were meta-synthesized into three themes: (1) The gateway to urgent support; (2) Values based crisis interventions and (3) Leadership and organizational values. Fragmented cross-agency responses exacerbated staff stress and created barriers to access. Services should focus on evaluating interagency working to improve staff role clarity and ensure boundaries between services are planned for. Organizations experienced as compassionate contributed positively to perceived accessibility but relied on compassionate leadership. Attending to the support needs of staff and the proximity of leaders to the front line of crisis care are key. Designing interventions that are easy to navigate, prioritize shared decision-making and reduce the risk of re-traumatizing people is a priority
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