1,721,006 research outputs found
Improving Irony and Stereotype Spreaders Detection using Data Augmentation and Convolutional Neural Network
Full text linkIn this paper we describe a deep learning model based on a Data Augmentation (DA) layer followed by a Convolutional Neural Network (CNN). The proposed model was developed by our team for the Profiling Irony and Stereotype Spreaders (ISSs) task proposed by the PAN 2022 organizers. As a first step, to classify an author as ISS or not (nISS), we developed a DA layer that expands each sample in the dataset provided. Using this augmented dataset we trained the CNN. Then, to submit our predictions, we apply our DA layer on the samples within the unlabeled test set too. Finally we fed our trained CNN with the augmented test set to generate our final predictions. To develop and test our model we used a 5-fold cross validation on the labelled training set. The proposed model reaches a maximum accuracy of 0.92 and an average accuracy of 0.89 over the five folds. Meanwhile, on the provided test set the proposed model reaches an accuracy of 0.9278
Automated test-set for accurate measurements of minimum noise figure of GaAs FETs
Full text linkA new automated method for the determination of input-termination optimum-condition of low noise microwave GaAs FETs is presented. Since the method is fully automated strong reduction of time-consumption is guaranteed; in addition the method is also accurate because all the effects which influences the noise figure measurements are taken into account. It is opinion of the Authors that both the test-set and the relevant software are unique
Complete characterization of GaAs low noise devices through noise figure test-set controlled by computer
No full textA new automated test-set for the characterization of low-noise devices in terms of noise, gain and scattering parameters
No full textA Fully Automated Method for Accurate Measurement of Geometrical Distortion in Magnetic Resonance Imaging of a 3D-Lattice Phantom
Full text linkThis paper describes an automated method for extracting the apparent positions of fiducial points from 2D or 3D images of a phantom. We consider a 3D-lattice phantom for two main reasons: first, ease of manufacture and isotropy of its structure with respect to coordinate projections; second, a connected structure allowing to uniquely assess the adjacency relationship between fiducial points even if geometric distortions arising from main magnet inhomogeneity and gradient fields non-linearity is severe as observed in open-bore systems.
In order to validate our proposed method and compare different choices for the parameters of our phantom (i.e. number and distance between grids and thickness of its branches) we developed in-house a software for simulating 2D or 3D volume images of the phantom, using customizable MRI sequence parameters and Spherical Harmonic Coefficients for the fields.
We deem worthy of note that using simulated images is the only way to evaluate the estimated position error, since it allows to compare the estimates to their theoretical counterparts. Furthermore, the use of simulated images allows to evaluate the robustness of the method with respect to image quality in terms of Signal-to-Noise Ratios and geometric distortion, and allows to evaluate different phantom geometries without having to manufacture them. The proposed method can be easily extended to phantoms having an arbitrary overall shape, as long as it is a fully connected structure. Specifically, it is easy to design a phantom with fiducial points laying outside of the homogeneity sphere, so that indirect measurement of the fields becomes possible, for example by using the recent method proposed by Acquaviva et al.
To the best of our knowledge, the proposed method outperforms other state-of-the-art methods, with an average positioning offset of 0.052 mm (with a 0.99 quantile of 0.12 mm) when working on images featuring a differential Signal-to-Noise Ratio within Region-of-Interest (ROI) equal to 105 (20.2 dB) and a ROI-to-background SNR of 20 dB. Estimating the positions of 6859 fiducial points in a volume, our highest density case, was carried out in less than 30 minutes on a desktop personal computer
Simple method for limiting delay of optimized interleavers for turbo-codes
No full textAn iterative interleaver growth algorithm is extended to allow the delay and required memory of designed interleavers to be halved with negligible performance loss. The original algorithm is efficient for two-component parallel concatenated turbo-codes with given constituent encoders that are optimum with regard to a cost function satisfying some mild conditions. However, it is only actually optimum if the selected set of patterns is representative of low-weight turbo-codewords. The new interleaver uses all terminating error patterns having an input weight not greater than a fixed IWX and single-coder output weight not greater than WX is proposed
Crystal Oscillator Error Compensation in Software Defined Radios for 5G Network Testbeds
No full textWhile Software Defined Radios (SDR) feature superior flexibility and ease of use, their sampling clock offset is also their main limitation, since compensating sampling rate errors incurs a significant complexity increase. In particular, a wireless cellular network Base Station is required a clock stability better than ±0.05ppm, while the TCXO found in most SDRs feature a ±2ppm stability. Therefore, an external time reference (e.g. GPSDO) is often employed to compensate clock errors. However, this solution might become costly in SDR-based experimental testbeds, since GPS is not always available and error compensation becomes imperative. Thus, this paper proposes a simple error measurement and compensation technique for SDRs without external reference sources. First, in the measurement phase, a GPSDO-locked device is used as reference. Then, the error correction method is implemented by modification of the Universal Hardware Driver (UHD) for Ettus USRP devices. In order to validate our calibration technique, we tested it on several low cost B210 SDRs, and we were able to setup a stable 5G SA FDD network without any external synchronization reference
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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