4,193 research outputs found

    A Deep Learning Model Compression and Ensemble Approach for Weed Detection

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    Site-specific weed management is an important practice in precision agriculture. Current advances in artificial intelligence have resulted in the use of large deep convolutional neural networks for weed detection. In this paper, a transfer learning, model compression, and ensemble learning approach is introduced that is suitable for resource-limited hardware such as mobile and embedded devices. The resulting ensemble model achieves 91.2% classification accuracy which is comparable to the performance of state-of-the-art deep learning models (such as the vanilla VGG16, DenseNet, and ResNet) while being about 62.22% smaller in size than DenseNet (the smallest-sized full-sized model). The approach used in this study is beneficial for further development of deep convolutional neural networks on smaller resource-limited hardware typically used in agriculture, as well as other industries such as healthcare and telecommunication

    Optical Nanotransmission Lines: Synthesis of Planar Left-Handed Metamaterials in the Infrared and Visible Regimes

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    Following our recent theoretical development of the concept of nano-inductors, nano-capacitors and nano-resistors at optical frequencies and the possibility of synthesizing more complex nano-scale circuits, here we theoretically investigate in detail the problem of optical nano-transmission-lines (NTL) that can be envisioned by properly joining together arrays of these basic nano-scale circuit elements. We show how, in the limit in which these basic circuit elements are closely packed together, the NTLs can be regarded as stacks of plasmonic and non-plasmonic planar slabs, which may be designed to effectively exhibit the properties of planar metamaterials with forward (right-handed) or backward (left-handed) operation. With the proper design, negative refraction and left-handed propagation are shown to be possible in these planar plasmonic guided-wave structures, providing possibilities for sub-wavelength focusing and imaging in planar optics, and laterally-confined waveguiding at IR and visible frequencies. The effective material parameters for such NTLs are derived, and the connection and analogy between these optical NTLs and the double-negative and double-positive metamaterials are also explored. Physical insights and justification for the results are also presented.Comment: 26 pages, 12 figures, accepted for publication in JOSA B, scheduled to appear March 200

    An Empirical Study Relating Construction Firm Performance and IT Utilization

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    This paper examines the impact of information technology (IT) utilization on construction firm performance. Based on empirical data collected from 74 US construction firms, the analyses provide evidence that IT has a positive impact on overall firm performance, schedule performance, and cost performance. Firm performance is a composite score of several metrics of performance: schedule performance, cost performance, customer satisfaction, safety performance, and profit. No relationship is found between IT utilization and customer satisfaction, safety, or profit, although this may be due to limitations of the study given strong correlations between IT utilization and cost and schedule performnance. The empirical evidence of positive association between performance and IT use provided by this research is significant to both construction practice and research literature. This evidence should encourage firms to adopt and invest in IT tools

    Enhanced activity of multiple TRIC-B channels : an endoplasmic reticulum/sarcoplasmic reticulum mechanism to boost counterion currents

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    The trimeric intracellular cation channels, TRIC-A and TRIC-B, represent two subtypes of sarcoplasmic reticulum (SR) K+-channel but their individual functional roles are unknown. We therefore compared the biophysical properties of SR K+-channels derived from the skeletal muscle of wild-type (WT) or Tric-a knockout (KO) mice. Because TRIC-A is the major TRIC-subtype in skeletal muscle, WT SR will predominantly contain TRIC-A channels, whereas Tric-a KO SR will only contain TRIC-B channels. When lone SR K+-channels were incorporated into bilayers, the open probability (Po) of channels from Tric-a KO mice was markedly lower than that of channels from WT mice; gating was characterized by shorter opening bursts and more frequent brief subconductance openings. However, unlike channels from WT mice, the Po of SR K+-channels from Tric-a KO mice increased as increasing channel numbers were present in the bilayer, driving the channels into long sojourns in the fully open state. When co-incorporated into bilayers, ryanodine receptor channels did not directly affect the gating of SR K+-channels, nor did the presence or absence of SR K+-channels influence ryanodine receptor activity. We suggest that because of high expression levels in striated muscle, TRIC-A produces most of the counterion flux required during excitation-contraction coupling. TRIC-B, in contrast, is sparsely expressed in most cells and, although lone TRIC-B channels exhibit low Po, the high Po levels reached by multiple TRIC-B channels may provide a compensatory mechanism to rapidly restore K+ gradients and charge differences across the SR of tissues containing few TRIC-A channels

    The role of polycyclic frameworks in modulating P2X<inf>7</inf> receptor function

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    Herein we describe our recent attempts to target the P2X7 receptor for potential treatment of neurological disorders. This work focusses on different polycycles including carborane, adamantane or cubane, joined by either a cyanoguanidine or an amide linker to phenyl or isoquinoline moieties. We have demonstrated the superiority of the adamantyl moiety over other polycycles in terms of synthetic accessibility and biological (cellular) activity. We have also shown that an amide or cyanoguanidine linker can greatly alter the biological activity of compounds. This SAR study provides important insights into the types of functionality required to target the P2X7 receptor

    Neonatal epididymo-orchitis caused by Pseudomonas aeruginosa: a case report

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    Epididymitis and epididymo-orchitis are an uncommon causes of acute testicular pain in neonatal boys, epididymo-orchitis is infection or inflammation of epididymis and testis it's may be associated with urinary tract infections or reflux of urine predisposed by an underlying vasal anomaly. Pediatricians should examine the testicles meticulously after a baby is born
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