2D Ginzburg-Landau System of Complex Modulation for Coupled Nonlinear Transmission Lines

In this paper a coupled mono-inductance transmission line is considered and the envelope modulation is reduced to the generalized 2D-Ginzburg-Landau system (2D-GL system). The case of scalar equation is also considered and we deduce from the obtained 2D-GL system a 2D-cubic Ginzburg-Landau equation (2D-GL equation) containing the derivatives with respect to one spatial variable in the cubic terms. The obtained 2D-GL system and 2D-GL equation admit spatial wave solutions. The modulational instability of these spatial wave solutions is investigated. In the case of the 2D-GL system we have restricted ourselves in the zero wavenumber of the perturbations, and the obtained modulational instability conditions depends only on the system’s coefficients and the wavenumber of the carriers. The modulational instability criterion is established for non zero wavenumber of the perturbation, and depends on both the wavenumber of the perturbation and the carrier. For the 2D-GL system we also study the coherent structures and present some numerical studies.      

Testing Parameter Change in General Integer‐Valued Time Series

We consider the structural change in a class of discrete valued time series, which the conditional distribution belongs to the one‐parameter exponential family. We propose a change point test based on the maximum likelihood estimator of the model's parameter. Under the null hypothesis (of no change), the test statistic converges to a well‐known distribution, allowing the calculation of the critical value of the test. The test statistic diverges to infinity under the alternative, meaning that the test has asymptotic power one. Some simulation results and real data applications are reported to show the effectiveness of the proposed procedure.     

Mosquito development and biological control in a macrophyte-based wastewater treatment plant.

A one-year study of the proliferation of mosquito in a Pistia stratiotes-based waste stabilization ponds in Cameroon revealed that Mansonia and Culex were the main breeding genera with about 55% and 42% of the total imagoes respectively. Though the ponds represent a favorable breeding ground for mosquitoes, only 0.02% of captured imagoes was Anopheles gambiae, suggesting that this wastewater treatment plant does not significantly contribute to the development of the malaria vector in the area. Gambusia sp. introduced to control mosquito population in the ponds acclimatized relatively well in most of the ponds (B3-B7) and their feeding rate without any diet ranged from 15.0 to 50.2 larvae/day for a single fish.     

An efficient coarse-grain multicomputer algorithm for the minimum cost parenthesizing problem

Several problems modeled by dynamic programming have been solved using a coarse-grain multicomputer parallel model (CGM for short). These problems use either polyadic dynamic programming or monadic non-serial dynamic programming. In this paper, we address the general case: we propose a parallel algorithm in the CGM model with p processors for the Optimal String Parenthesizing Problem or Minimum Cost Parenthesizing Problem, which is a typical polyadic non-serial dynamic programming problem. The algorithm we obtain requires ?(2p)^1/2? communication rounds and, at most, O(n ³/p) time-steps on p processors. This new CGM algorithm performs better than the previously most efficient solution, which uses p communication rounds.     

Synthesis of graphene paper from pyrolyzed asphalt

A new technique for the synthesis of large sheets (>10 cm²) of multi-layered graphene is presented. The condensation onto a heated surface (≈650 °C) of fumes from the thermal decomposition of asphalt in a ceramic crucible produces carbon films with a metallic sheen. Heating was done by a Fisher burner (natural gas/air) flame and the crucible was covered but exposed to laboratory atmosphere. These films were determined to be multi-layered graphene by scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy (XPS), Raman and infrared spectroscopy and X-ray diffraction. XPS indicates that the films are primarily sp² hybridized carbon with small amounts of sp³ C–H and C–O or C–N functionalities. Based on the D band shift (1593 cm⁻¹) and the ratio of D band to G band (1354 cm⁻¹) of 0.93, the Raman spectrum also indicates that the material is sp² C with some nanocrystalline features. The infrared spectrum exhibits A_1U (868 cm⁻¹) and E_1U (1599 cm⁻¹) stretching of the intralayer bonds of graphene. This form of chemical vapor deposition may be a scalable to give much larger surface areas. Furthermore, the process does not require metal substrates. Deposition onto silica nanosprings and diatomites is demonstrated.     

Acute hemodialysis complications in end‐stage renal disease patients: The burden and implications for the under‐resourced Sub‐Saharan African health systems

Little is known about the challenges of routine renal replacement therapy in Sub‐Saharan Africa. We investigated the fatal and nonfatal acute hemodialysis (HD) complications in patients with end‐stage renal disease (ESRD) in two main dialysis centers in Cameroon. 1000 consecutive HD sessions incurred over a 4‐month period by 129 patients (96 men, 74%) with ESRD, receiving two weekly HD sessions of 4 hours each, were considered. Personal and clinical profiles before, during, and within 24 hours after HD sessions were used to diagnose complications. Participants were aged 7 to 80 years (mean 46 years). In all, 452 acute complications were recorded in 411 (41%) of the 1000 HD sessions. Of the 11 types of complications, hypotension (25%), muscular cramps (22%), hypertensive crisis (14%), pruritus (10%), and fever (7%) were the most frequent. Three hundred and six complications (67.7%) occurred during understaffed nighttime. The vascular access was the main bleeding site with 64%. Being diabetic and ultrafiltration rate >1000 mL/h were associated with hypotension and muscle cramps. The shorter duration in dialysis was associated with the risk of bleeding and the disequilibrium syndrome while longer duration was associated with muscle cramps. Four deaths (three from bleeding and one from disequilibrium syndrome) occurred, all during nighttime. Nearly half of dialysis sessions in these settings are associated with acute complications, some of which are fatal. Those complications occurred mostly during understaffed periods. Urgent strategies are needed to quickly solve the human capital crisis in the health care sector.     

Testing for parameter constancy in general causal time‐series models

We consider a process belonging to a large class of causal models including AR(∞), ARCH(∞), TARCH(∞),… processes. We assume that the model depends on a parameter and consider the problem of testing for change in the parameter. Two statistics and are constructed using quasi‐likelihood estimator of the parameter. Under the null hypothesis that there is no change, it is shown that each of these two statistics weakly converges to the supremum of the sum of the squares of independent Brownian bridges. Under the alternative of a change in the parameter, we show that the test statistic diverges to infinity. Some simulation results for AR(1), ARCH(1), GARCH(1,1) and TARCH(1) models are reported to show the applicability and the performance of our procedure with comparisons to some other approaches.     

Multistability and circuit implementation of tabu learning two-neuron model: application to secure biomedical images in IoMT

Neural Computing and Applications - In this paper, the dynamics of a non-autonomous tabu learning two-neuron model is investigated. The model is obtained by building a tabu learning two-neuron...     

Remerging Feigenbaum Trees,Coexisting Behaviors and Bursting Oscillations in a Novel 3D Generalized Hopfield Neural Network

Neural Processing Letters - This paper, a novel 3D generalized Hopfield neural network is proposed and investigated in order to generate and highlight some unknown behaviors related to such type of...