An efficient and accurate technique for the incident-wave excitations in the FDTD method

Cataloged from PDF version of article.An efficient technique to improve the accuracy of the finite-difference time-domain (FDTD) solutions employing incident-wave excitations is developed. In the separate-field formulation of the FDTD method, any incident wave may be efficiently introduced to the three-dimensional (3-D) computational domain by interpolating from a one-dimensional (1-D) incident-field array (IFA), which is a 1-D FDTD grid simulating the propagation of the incident wave. By considering the FDTD computational domain as a sampled system and the interpolation operation as a decimation process, signal-processing techniques are used to identify and ameliorate the errors due to aliasing. The reduction in the error is demonstrated for various cases. This technique can be used for the excitation of the FDTD grid by any incident wave. A fast technique is used to extract the amplitude and the phase of a sampled sinusoidal signal

Structured least squares with bounded data uncertainties

In many signal processing applications the core problem reduces to a linear system of equations. Coefficient matrix uncertainties create a significant challenge in obtaining reliable solutions. In this paper, we present a novel formulation for solving a system of noise contaminated linear equations while preserving the structure of the coefficient matrix. The proposed method has advantages over the known Structured Total Least Squares (STLS) techniques in utilizing additional information about the uncertainties and robustness in ill-posed problems. Numerical comparisons are given to illustrate these advantages in two applications: signal restoration problem with an uncertain model and frequency estimation of multiple sinusoids embedded in white noise. ©2009 IEEE

Predictors for prolonged hospital stay solely to complete intravenous antifungal treatment in patients with candidemia: Results from the ECMM candida III multinational European observational cohort study

Background To date, azoles represent the only viable option for oral treatment of invasive Candida infections, while rates of azole resistance among non-albicans Candida spp. continue to increase. The objective of this sub-analysis of the European multicenter observational cohort study Candida III was to describe demographical and clinical characteristics of the cohort requiring prolonged hospitalization solely to complete intravenous (iv) antifungal treatment (AF Tx). Methods Each participating hospital (number of eligible hospitals per country determined by population size) included the first ~ 10 blood culture proven adult candidemia cases occurring consecutively after July 1st, 2018, and treating physicians answered the question on whether hospital stay was prolonged only for completion of intravenous antifungal therapy. Descriptive analyses as well as binary logistic regression was used to assess for predictors of prolonged hospitalization solely to complete iv AF Tx. Findings Hospital stay was prolonged solely for the completion of iv AF Tx in 16% (100/621) of candidemia cases by a median of 16 days (IQR 8 – 28). In the multivariable model, initial echinocandin treatment was a positive predictor for prolonged hospitalization to complete iv AF Tx (aOR 2.87, 95% CI 1.55 – 5.32, p < 0.001), while (i) neutropenia, (ii) intensive care unit admission, (iii) catheter related candidemia, (iv) total parenteral nutrition, and (v) C. parapsilosis as causative pathogen were found to be negative predictors (aOR 0.22 – 0.45; p < 0.03). Interpretation Hospital stays were prolonged due to need of iv AF Tx in 16% of patients with candidemia. Those patients were more likely to receive echinocandins as initial treatment and were less severely ill and less likely infected with C. parapsilosis

Guideline adherence and survival of patients with candidaemia in Europe: results from the ECMM Candida III multinational European observational cohort study

© 2022 Elsevier Ltd. All rights reserved.[Background] The European Confederation of Medical Mycology (ECMM) collected data on epidemiology, risk factors, treatment, and outcomes of patients with culture-proven candidaemia across Europe to assess how adherence to guideline recommendations is associated with outcomes.[Methods] In this observational cohort study, 64 participating hospitals located in 20 European countries, with the number of eligible hospitals per country determined by population size, included the first ten consecutive adults with culture-proven candidaemia after July 1, 2018, and entered data into the ECMM Candida Registry (FungiScope CandiReg). We assessed ECMM Quality of Clinical Candidaemia Management (EQUAL Candida) scores reflecting adherence to recommendations of the European Society of Clinical Microbiology and Infectious Diseases and the Infectious Diseases Society of America guidelines.[Findings] 632 patients with candidaemia were included from 64 institutions. Overall 90-day mortality was 43% (265/617), and increasing age, intensive care unit admission, point increases in the Charlson comorbidity index score, and Candida tropicalis as causative pathogen were independent baseline predictors of mortality in Cox regression analysis. EQUAL Candida score remained an independent predictor of mortality in the multivariable Cox regression analyses after adjusting for the baseline predictors, even after restricting the analysis to patients who survived for more than 7 days after diagnosis (adjusted hazard ratio 1·08 [95% CI 1·04–1·11; p<0·0001] in patients with a central venous catheter and 1·09 [1·05–1·13; p<0·0001] in those without one, per one score point decrease). Median duration of hospital stay was 15 days (IQR 4–30) after diagnosis of candidaemia and was extended specifically for completion of parenteral therapy in 100 (16%) of 621 patients. Initial echinocandin treatment was associated with lower overall mortality and longer duration of hospital stay among survivors than treatment with other antifungals.[Interpretation] Although overall mortality in patients with candidaemia was high, our study indicates that adherence to clinical guideline recommendations, reflected by higher EQUAL Candida scores, might increase survival. New antifungals, with similar activity as current echinocandins but with longer half-lives or oral bioavailability, are needed to reduce duration of hospital stay.Scynexis.Peer reviewe

Accurate plane-wave excitation in the FDTD method

Different techniques are developed to implement plane-wave excitation on the finite-difference time-domain (FDTD) method, such as the initial-condition, the hard-source, and the connecting-condition techniques, for the total-field/scattered field (TF/SF) formulation. In the TF/SF formulation, the incident field is computed and fed to the 3D FDTD grid on the boundary separating the total-field and the scattered-field regions. Since the incedent field is a known quantity, a closed-form expression can be evaluated on every point of this boundary. A more efficient way of computing the incedent field is by using an incedent-field array (IFA), which is a 1D FDTD grid set-up to numerically propagate the incedent field into the 3D FDTD

A Supervised Biclustering Optimization Model for Feature Selection in Biomedical Dataset Classification

Biclustering groups samples and features simultaneously in the given set of data. When biclusters are obtained from the data, clusters of samples and clusters of features that determine the partitioning of samples into the underlying clusters are also obtained. We focus on a supervised biclustering problem leading to unsupervised feature selection. We formulate this problem as an optimization model which aims to maximize classification accuracy by selecting a small subset of features. We solve the model with exact and inexact solution methods based on optimization techniques. Microarray cancer datasets are used to experiment our approach