Retardation and reduction of pulse distortion by group-velocity dispersion through pulse shaping

We show that a reduction in the pulse distortion caused by chromatic dispersion can be achieved through pulse shaping. We argue that a simple binary phase mask in the Fourier plane of the laser spectrum can improve the transmission of short pulses in a dispersive channel through reduced broadening. The argument was tested experimentally, and a good agreement was found with the theory

Group Validation in Recommender Systems: Framework for Multi-layer Performance Evaluation

Interpreting the performance results of models that attempt to realize user behavior in platforms that employ recommenders is a big challenge that researchers and practitioners continue to face. Although current evaluation tools possess the capacity to provide solid general overview of a system's performance, they still lack consistency and effectiveness in their use as evident in most recent studies on the topic. Current traditional assessment techniques tend to fail to detect variations that could occur on smaller subsets of the data and lack the ability to explain how such variations affect the overall performance. In this article, we focus on the concept of data clustering for evaluation in recommenders and apply a neighborhood assessment method for the datasets of recommender system applications. This new method, named neighborhood-based evaluation, aids in better understanding critical performance variations in more compact subsets of the system to help spot weaknesses where such variations generally go unnoticed with conventional metrics and are typically averaged out. This new modular evaluation layer complements the existing assessment mechanisms and provides the possibility of several applications to the recommender ecosystem such as model evolution tests, fraud/attack detection and a possibility for hosting a hybrid model setup

A reconfigurable architecture for the FFT operator in a Software Radio context

International audienceThe ”SoftWare Radio (SWR)” concept has become a topic of widespread interest for reconfigurable mobile architecture design. It is seen as the next evolutionary step in the mobile communications. In this context of SWR, a way to decrease the runtime of the software reconfiguration and to optimize the sharing between the software and the hardware of the execution platform called ”parametrization” was introduced. This technique is based on two approaches, the first one is called the Common Function approach, the second one is called the Common Operator approach. Being interested on the second parametrization technique, we propose in this paper a reconfigurable FFT (Fast Fourier Transform) operator. This operator can be reconfigured to switch from an operator dedicated to compute the FFT in the complex field (i.e for OFDM modulation or frequential equalization) to an operator which computes the FFT in the Galois Field in order to perform Reed-Solomon (RS) encoding and two steps of the decoding process

A Reconfigurable Butterfly Architecture for Fourier and Fermat Transforms

International audienceReconfiguration is an essential part of Soft- Ware Radio (SWR) technology. Thanks to this technique, systems are designed for change in operating mode with the aim to carry out several types of computations. In this SWR context, the Fast Fourier Transform (FFT) operator was defined as a common operator for many classical telecommunications operations [1]. In this paper we propose a new architecture for this operator that makes it a device intended to perform two different transforms. The first one is the Fast Fourier Transform (FFT) used for the classical operations in the complex field. The second one is the Fermat Number Transform (FNT) in the Galois Field (GF) for channel coding and decoding

Momelotinib in myelofibrosis patients with thrombocytopenia: Post hoc analysis from three randomized phase 3 trials

The oral activin A receptor type I, Janus kinase 1 (JAK1), and JAK2 inhibitor momelotinib demonstrated symptom, spleen, and anemia benefits in intermediate- and high-risk myelofibrosis (MF). Post hoc analyses herein evaluated the efficacy and safety of momelotinib in patients with MF and thrombocytopenia (platelet counts \u3c100 × 1

Minimal basilar membrane motion in low-frequency hearing

Low-frequency hearing is critically important for speech and music perception, but no mechanical measurements have previously been available from inner ears with intact low-frequency parts. These regions of the cochlea may function in ways different from the extensively studied high-frequency regions, where the sensory outer hair cells produce force that greatly increases the sound-evoked vibrations of the basilar membrane. We used laser interferometry in vitro and optical coherence tomography in vivo to study the low-frequency part of the guinea pig cochlea, and found that sound stimulation caused motion of a minimal portion of the basilar membrane. Outside the region of peak movement, an exponential decline in motion amplitude occurred across the basilar membrane. The moving region had different dependence on stimulus frequency than the vibrations measured near the mechanosensitive stereocilia. This behavior differs substantially from the behavior found in the extensively studied high-frequency regions of the cochlea