576 research outputs found

    Automated Generation of Geometric Theorems from Images of Diagrams

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    We propose an approach to generate geometric theorems from electronic images of diagrams automatically. The approach makes use of techniques of Hough transform to recognize geometric objects and their labels and of numeric verification to mine basic geometric relations. Candidate propositions are generated from the retrieved information by using six strategies and geometric theorems are obtained from the candidates via algebraic computation. Experiments with a preliminary implementation illustrate the effectiveness and efficiency of the proposed approach for generating nontrivial theorems from images of diagrams. This work demonstrates the feasibility of automated discovery of profound geometric knowledge from simple image data and has potential applications in geometric knowledge management and education.Comment: 31 pages. Submitted to Annals of Mathematics and Artificial Intelligence (special issue on Geometric Reasoning

    The dynamic predictive power of company comparative networks for stock sector performance

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    As economic integration and business connections increase, companies actively interact with each other in the market in cooperative or competitive relationships. To understand the market network structure with company relationships and to investigate the impacts of market network structure on stock sector performance, we propose the construct of a company comparative network based on public media data and sector interaction metrics based on the company network. All the market network structure metrics are integrated into a vector autoregression model with stock sector return and risk. Several findings demonstrate the dynamic relationships that exist between sector interactions and sector performance. First, sector interaction metrics constructed based on company networks are significant leading indicators of sector performance. Interestingly, the interactions between sectors have greater predictive power than those within sectors. Second, compared with the company closeness network, the company comparative network, which labels the cooperative or competitive relationships between companies, is a better construct to understand and predict sector interactions and performance. Third, competitive company interactions between sectors impact sector performance in a slower manner than cooperative company interactions. The findings enrich financial studies regarding asset pricing by providing additional explanations of company/sector interactions and insights into company management using industry-level strategies

    Strengthening of Rural Bridges using Rapid-Installation FRP Technology: Route 63 Bridge No. H356, Phelps County

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    This report presents the use of externally bonded fiber reinforced polymers (FRP) laminates for the flexural strengthening of a concrete bridge. The bridge selected for this project is a two-span simply supported reinforced concrete slab with no transverse steel reinforcement located in Phelps County, MO. The original construction combined with the presence of very rigid parapets caused the formation of a 1-inch wide longitudinal crack, which resulted in the slab to behave as two separate elements. The structural behavior was verified using a finite element model (FEM) of the bridge. The bridge analysis was performed for maximum loads determined in accordance with AASHTO 4th edition. The strengthening scheme was designed in compliance with the ACI 440.2R-08 design guide for externally bonded FRP materials, to avoid further cracking and such that the transverse flexural capacity be higher than the cracking moment. The FRP strengthening technique was rapidly implemented. After the strengthening, a load test was performed to validate the bridge model and evaluate the structural behavior according to the AASHTO specifications. The bridge deck was retrofitted after the longitudinal crack was injected with epoxy to allow continuity in the cross section

    A Novel Counterfactual Data Augmentation Method for Aspect-Based Sentiment Analysis

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    Aspect-based-sentiment-analysis (ABSA) is a fine-grained sentiment evaluation task, which analyzes the emotional polarity of the evaluation aspects. Generally, the emotional polarity of an aspect exists in the corresponding opinion expression, whose diversity has great impact on model's performance. To mitigate this problem, we propose a novel and simple counterfactual data augmentation method to generate opinion expressions with reversed sentiment polarity. In particular, the integrated gradients are calculated to locate and mask the opinion expression. Then, a prompt combined with the reverse expression polarity is added to the original text, and a Pre-trained language model (PLM), T5, is finally was employed to predict the masks. The experimental results shows the proposed counterfactual data augmentation method performs better than current augmentation methods on three ABSA datasets, i.e. Laptop, Restaurant, and MAMS.Comment: Camera-ready for ACML 202

    Design, Construction and Load Testing of the Bridge on Arnault Branch, Washington County, Missouri using Innovative Technologies

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    The superstructure and instrumentation designs of a three-span bridge are presented in this report. The three spans include a precast box-girder bridge, a precast deck on steel girder and a precast deck on concrete girder. They were designed to compare the performance of various bridge decks reinforced with fiber reinforced polymers (FRP) through field instrumentations. A wireless monitoring system was designed to facilitate the collection of field data after the completion of bridge construction. The collected data will allow the study of FRP bars and stay-in-place FRP grid systems

    Condition Assessment of Bill Emerson Memorial Cable-Stayed Bridge under Postulated Design Earthquake

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    In this study, a three-dimensional finite element model of the Bill Emerson Memorial cable-stayed bridge was developed and validated with the acceleration data recorded during the M4.1 earthquake of May 1, 2005, in Manila, Arkansas. The model took into account the geometric nonlinear properties associated with cable sagging and soil-foundation-structure interaction. The validated model was used to evaluate the performance of a seismic protective system, the behavior of cable-stayed spans, and the accuracy of two simplified bridge models that have been extensively used by the structural control community. The calculated natural frequencies and mode shapes correlated well with the measured data. Except that the hollow columns of two H-shaped towers were near yielding immediately above their capbeams, the cable-stayed spans behaved elastically as expected under the design earthquake that was scaled up from the recorded rock motions at the bridge site. The minimum factor of safety of all cables is 2.78, which is slightly greater than the design target

    rDNA internal transcribed spacer sequence analysis of Lycoris Hert.

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    The interspecific relationships of Lycoris species were studied by internal transcribed spacer (ITS) sequences. ITS fragments of 14 species were amplified, sequenced and analysed. The results showed that ITS sequences of 14 species were different from each other and the ITS lengths of 14 species were about 652 bp. The GC content of ITS2 sequences was bigger than that of ITS1. Clustering results based on ITS sequences showed that Lycoris species could be divided into three clades. The classification was basically consistent with those of karyotype and morphology. This paper suggested that the likelihood of hybrid origin of Lycoris species was supported and ITS could be used as a good molecular marker to identify plants of Lycoris.Keywords: Lycoris Hert., internal transcribed spacer (ITS), molecular taxonomy, interspecific relationshipAfrican Journal of Biotechnology Vol. 11(29), pp. 7361-7365, 10 April, 201

    Gate-controlled reversible rectifying behaviour in tunnel contacted atomically-thin MoS2_{2} transistor

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    Atomically-thin 2D semiconducting materials integrated into van der Waals heterostructures have enabled architectures that hold great promise for next generation nanoelectronics. However, challenges still remain to enable their full acceptance as compliant materials for integration in logic devices. Two key-components to master are the barriers at metal/semiconductor interfaces and the mobility of the semiconducting channel, which endow the building-blocks of pn{pn} diode and field effect transistor. Here, we have devised a reverted stacking technique to intercalate a wrinkle-free h-BN tunnel layer between MoS2_{2} channel and contacting electrodes. Vertical tunnelling of electrons therefore makes it possible to suppress the Schottky barriers and Fermi level pinning, leading to homogeneous gate-control of the channel chemical potential across the bandgap edges. The observed unprecedented features of ambipolar pn{pn} to np{np} diode, which can be reversibly gate tuned, paves the way for future logic applications and high performance switches based on atomically thin semiconducting channel.Comment: 23 pages, 5 main figures + 9 SI figure
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