9,476 research outputs found

    CSWA: Aggregation-Free Spatial-Temporal Community Sensing

    Full text link
    In this paper, we present a novel community sensing paradigm -- {C}ommunity {S}ensing {W}ithout {A}ggregation}. CSWA is designed to obtain the environment information (e.g., air pollution or temperature) in each subarea of the target area, without aggregating sensor and location data collected by community members. CSWA operates on top of a secured peer-to-peer network over the community members and proposes a novel \emph{Decentralized Spatial-Temporal Compressive Sensing} framework based on \emph{Parallelized Stochastic Gradient Descent}. Through learning the \emph{low-rank structure} via distributed optimization, CSWA approximates the value of the sensor data in each subarea (both covered and uncovered) for each sensing cycle using the sensor data locally stored in each member's mobile device. Simulation experiments based on real-world datasets demonstrate that CSWA exhibits low approximation error (i.e., less than 0.2∘0.2 ^\circC in city-wide temperature sensing task and 1010 units of PM2.5 index in urban air pollution sensing) and performs comparably to (sometimes better than) state-of-the-art algorithms based on the data aggregation and centralized computation.Comment: This paper has been accepted by AAAI 2018. First two authors are equally contribute

    Effects of Volcanic Emissions on Clouds During Kilauea Degassing Events

    Get PDF
    Aerosols influence Earths radiative balance directly by scattering and absorbing solar radiation, and indirectly by modifying cloud properties. Current scientific consensus indicates that these effects may offset as much as 50% of the warming due to greenhouse gas emissions. Over the last two decades dramatic volcanic events in Hawaii have produced localized aerosol emissions in otherwise clean environments. These are natural experiments" where the aerosol effects on clouds and climate can be partitioned from other effects like meteorology and industrial emissions. Therefore, these events provide a unique opportunity to learn about possible effects of aerosol pollution on climate through cloud modification. In this work we use the version 5 of the NASA Goddard Earth Observing System (GEOS-5) and satellite retrievals to analyze and evaluate the strength of the aerosol indirect effect on liquid and ice clouds during the 2008 and 2018 Kilauea degassing events using different emissions scenarios (0, 1, and 5 actual emissions). Our results suggested that the 2018 event was stronger and more regionally significant with respect to cloud formation process for both liquid and ice clouds, while the 2008 affected local liquid clouds only. GEOS-5 predictions reproduced spatial patterns for all parameters, however better precision could be gained by using more accurate plume parameters for height and ash concentration

    Mortality time of immature stages of susceptible and resistant strains of Sitophilus oryzae (L.) exposed to different phosphine concentrations

    Get PDF
    The mortality time on egg, larvae and pupae of four strains with resistance factor 1, 69, 160 and 295 to phosphine of Sitophilus oryzae (L.), which were expressed in R1, R69, R160 and R295 in this report, respectively, were investigated with stable concentrations of 100, 300, 500, 700 and 900 mL m-3 of phosphine in a well sealed fumigation chamber. The mortality time on all immature stages was about 10 d for strain R1, more than 15 d for all resistance strains exposed to 100 mL m-3 of phosphine. Mortality time on egg and larvae of R1 was 9 and 6 d at 300 and 700 mL m-3, respectively. But it was only 4 d and 2 d for pupae of R1 at 700 and 900 mL m-3, respectively. The mortality time on immature stages of R69 was 12 and 5 d with the 300 and 700 mL m-3, respectively. And that on immature stages of strain R160 and R295 was 15 and 10 d with phosphine of 300-700 mL m-3, respectively. With the fumigant of 900 mL m-3, the full death time were 5 d for larval of all strains, 5d for pupae and egg of R1 and more that 8 or 9 d for pupae and egg of three resistance strains. The egg and pupae of S. oryzae were the most tolerant stages to phosphine both for susceptible and resistance strains.Keywords: Sitophilius oryzae, Immature stage, Phosphine, Mortality tim

    Ultrasonic-assisted extraction and evaluation of biological activities of flavonoids from Flemingia philippinensis Merr et Rolfe

    Get PDF
    Purpose: To develop a simple and rapid method for extracting total flavonoids from the roots of Flemingia philippinensis and to investigate the antioxidant and anti-tumor activities of the extracts of the materials from various locations in China.Methods: The total flavonoids in F. philippinensis were obtained by ultrasonic-assisted conventional solvent extraction method, and the extraction conditions were optimized by single factor and orthogonal test. 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and anti-tumor activities, using 3-(4,5- dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide (MTT) assay, of the extract were evaluated. The contents of flemiphilippinin A, auriculasin, 5,7,3',4'-tetrahydroxy-6,8 –diprenylisoflavone and dorsmanins I were also determined.Results: Optimal extraction conditions were as follows: extraction time, 40 min; methanol concentration, 85 %; and solvent to solid ratio, 40 mL/g; and number of extraction, once. Total flavonoid content varied greatly (3.7 - 14.35 %) among the 19 samples collected from different origins in China. Flemiphilippin A, 5,7,3',4'- tetrahydroxy-6,8 -diprenylisoflavone, auriculasin and dorsmanins I showed varying DPPH radical scavenging activities with effective half maximal concentration (EC50) of 18.36, 23.59, 57.25 and 63.54 μg/mL, respectively.  Flemiphilippinin A (5 μg/mL) also exhibited some level of antitumor activity against human hepatocellular carcinoma cell (BEL-7402), human lung epithelial (A-549) and human ileocecal adenocarcinoma cell (HCT-8) with inhibition of 91.13 ± 1.6, 91.22 ± 3.23, and 79.77 ± 3.57 %, respectively.Conclusion: Total flavonoids can be extracted efficiently from F.  philippinensis by ultrasonic-assisted extraction method. Flemiphilippinin A has a potential for use in medicine as an antioxidant and antitumor drug

    Validity and reliability of a phone App and stopwatch for the measurement of 505 change of direction performance: a test-retest study design

    Get PDF
    Purpose: The aim of this study was to explore the validity and reliability of a phone app (named: COD timer) and stopwatches for the measurement of change of direction (COD) performance. Methods: Sixty-two youth basketball players (age: 15.9 ± 1.4 yrs, height: 178.8 ± 11.0 cm, body mass: 70.0 ± 14.1 kg) performed six trials of 505 COD test (with the left side being the plant leg first, then the right side). The completion time was measured simultaneously via timing gates (with error correction processing algorithms), the phone app and stopwatches. Results: There was an almost perfect correlation and agreement between timing gates and COD timer (r = 0.978; SEE = 0.035 s; LoA =-0.08~0.06 s), but a lower correlation and agreement between timing gates and stopwatch (r = 0.954; SEE = 0.050 s; LoA =-0.17~0.04 s) with statistical significance in completion time (ES = 1.29, 95%CI: 1.15-1.43, p < 0.01). The coefficient of variation revealed similar level of dispersion between the three timing devices (timing gates: 6.58%; COD timer: 6.32%; stopwatch: 6.71%). Inter-observer reliability (ICC = 0.991) and test-retest reliability (ICC = 0.998) were excellent in COD timer, while the inter-observer reliability was lower (ICC = 0.890) in the stopwatches. Conclusion: In the 505 COD test, the COD timer was able to provide a valid and reliable measurement. On the contrary, stopwatch was not recommended because of large error. Thus, if timing gates are unavailable, practitioners can adopt the COD timer app to assess 505 COD speed times

    Ventilation and Temperature Control for Energy-efficient and Healthy Buildings: A Differentiable PDE Approach

    Full text link
    In this paper, we introduce a novel framework for building learning and control, focusing on ventilation and thermal management to enhance energy efficiency. We validate the performance of the proposed framework in system model learning via two case studies: a synthetic study focusing on the joint learning of temperature and CO2 fields, and an application to a real-world dataset for CO2 field learning. For building control, we demonstrate that the proposed framework can optimize the control actions and significantly reduce the energy cost while maintaining a comfort and healthy indoor environment. When compared to existing traditional methods, an optimization-based method with ODE models and reinforcement learning, our approach can significantly reduce the energy consumption while guarantees all the safety-critical air quality and control constraints. Promising future research directions involve validating and improving the proposed PDE models through accurate estimation of airflow fields within indoor environments. Additionally, incorporating uncertainty modeling into the PDE framework for HVAC control presents an opportunity to enhance the efficiency and reliability of building HVAC system management

    Effects of unilateral vs. bilateral resistance training interventions on measures of strength, jump, linear and change of direction speed: a systematic review and meta-analysis

    Get PDF
    Background: Exercises can be categorized into either unilateral or bilateral movements. Despite the topic popularity, the answer to the question as to which (unilateral or bilateral) is superior for a certain athletic performance enhancement remains unclear. Purpose: To compare the effect of unilateral and bilateral resistance training interventions on measures of athletic performance. Methods: Keywords related with unilateral, bilateral and performance were used to search in the Web of Science, Pubmed databases, and Google Scholar and ResearchGateâ„¢ websites. Results: 6365 articles were initially identified, 14 met the inclusion criteria and were included in the final analysis, with overall article quality being deemed moderate. The quantitative analysis comprised 392 subjects (aged: 16 to 26 years). Sub-group analysis showed that unilateral exercise resistance training resulted in a large effect in improving unilateral jump performance compared to bilateral training (ES = 0.89 [0.52, 1.26]). In contrast, bilateral exercise resistance training showed a small effect in improving bilateral strength compared to unilateral (ES = -0.43 [-0.71, -0.14]). Non-significant differences were found in improving unilateral strength (ES = 0.26 [-0.03, 0.55]), bilateral jump performance (ES = -0.04 [-0.31, 0.23]), change of direction (COD) (ES = 0.31 [-0.01, 0.63]) and speed (ES = -0.12 [-0.46, 0.21]) performance. Conclusion: Unilateral resistance training exercises should be chosen for improving unilateral jumping performance, and bilateral resistance training exercises should be chosen for improving bilateral strength performance
    • …
    corecore