44 research outputs found

    Texture analysis using the trace transform

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    EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    A Temporal Neural Trace of Wavelet Coefficients in Human Object Vision: An MEG Study

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    Wavelet transform has been widely used in image and signal processing applications such as denoising and compression. In this study, we explore the relation of the wavelet representation of stimuli with MEG signals acquired from a human object recognition experiment. To investigate the signature of wavelet descriptors in the visual system, we apply five levels of multi-resolution wavelet decomposition to the stimuli presented to participants during MEG recording and extract the approximation and detail sub-bands (horizontal, vertical, diagonal) coefficients in each level of decomposition. Apart from, employing multivariate pattern analysis (MVPA), a linear support vector classifier (SVM) is trained and tested over the time on MEG pattern vectors to decode neural information. Then, we calculate the representational dissimilarity matrix (RDM) on each time point of the MEG data and also on wavelet descriptors using classifier accuracy and one minus Pearson correlation coefficient, respectively. Given the time-courses calculated from performing the Pearson correlation between the wavelet descriptors RDMs and MEG decoding accuracy in each time point, our result shows that the peak latency of the wavelet approximation time courses occurs later for higher level coefficients. Furthermore, studying the neural trace of detail sub-bands indicates that the overall number of statistically significant time points for the horizontal and vertical detail coefficients is noticeably higher than diagonal detail coefficients, confirming the evidence of the oblique effect that the horizontal and vertical lines are more decodable in the human brain

    Rationale and Design of a Registry in a Referral and Educational Medical Center in Tehran, Iran: Sina Hospital Covid-19 Registry (SHCo-19R)

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    Coronavirus disease 2019 (Covid-19) is caused by the novel coronavirus resulting in a highly contagious respiratory tract infection with an increased risk of acute respiratory distress syndrome (ARDS), which was first seen in Wuhan, China. Thus far, this virus has spread to many countries worldwide, including Iran. Multiple studies have assessed disease characteristics, viral genetics, and complications of Covid-19 in the Chinese population. However, there is limited data regarding patient characteristics and outcomes of infected cases outside of China. Besides, risk factors of adverse outcomes are poorly identified in different populations. Due to limited data in the Iranian population affected by the virus, we aimed to design a registry of patients with Covid-19 at Sina Hospital in Tehran, Iran [Sina Hospital Covid-19 Registry (SHCo-19R)] in this regard, to assess patient characteristics, imaging features, laboratory findings, management strategies, and adverse outcomes of Iranian patients with Covid-19 and their differences with other populations

    Modeling Lane-Changing Behavior in a Connected Environment: A Game Theory Approach

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    AbstractVehicle-to-Vehicle communications provide the opportunity to create an internet of cars through the recent advances in communication technologies, processing power, and sensing technologies. Aconnected vehicle receives real-time information from surrounding vehicles; such information can improve drivers’ awareness about their surrounding traffic condition and lead to safer and more efficient driving maneuvers. Lane-changing behavior,as one of the most challenging driving maneuvers to understand and to predict, and a major source of congestion and collisions, can benefit from this additional information.This paper presents a lane-changing model based on a game-theoretical approach that endogenously accounts for the flow of information in a connected vehicular environment.A calibration approach based on the method of simulated moments is presented and a simplified version of the proposed framework is calibrated against NGSIM data. The prediction capability of the simplified model is validated. It is concluded the presented framework is capable of predicting lane-changing behavior with limitations that still need to be addressed.Finally, a simulation framework based on the fictitious play is proposed. The simulation results revealed that the presented lane-changing model provides a greater level of realism than a basic gap-acceptance model

    Review of coreference resolution in English and Persian

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    Coreference resolution (CR) is one of the most challenging areas of natural language processing. This task seeks to identify all textual references to the same real-world entity. Research in this field is divided into coreference resolution and anaphora resolution. Due to its application in textual comprehension and its utility in other tasks such as information extraction systems, document summarization, and machine translation, this field has attracted considerable interest. Consequently, it has a significant effect on the quality of these systems. This article reviews the existing corpora and evaluation metrics in this field. Then, an overview of the coreference algorithms, from rule-based methods to the latest deep learning techniques, is provided. Finally, coreference resolution and pronoun resolution systems in Persian are investigated.Comment: 44 pages, 11 figures, 5 table
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