Structural identifiability of viscoelastic mechanical systems

We solve the local and global structural identifiability problems for viscoelastic mechanical models represented by networks of springs and dashpots. We propose a very simple characterization of both local and global structural identifiability based on identifiability tables, with the purpose of providing a guideline for constructing arbitrarily complex, identifiable spring-dashpot networks. We illustrate how to use our results in a number of examples and point to some applications in cardiovascular modeling.Comment: 3 figure

Compact wideband multilayer microstrip coupled lines bandpass filter for X-band application

A wideband bandpass filter for X-band application using multilayer microstrip coupled lines is presented in this article. Strong coupling required for wideband filter is realized by arranging multiple layers of microstrip lines on two different dielectric substrates and by overlapping these lines. The filter is fabricated on 0.254 mm thickness R/T Duroid 6010 and R/T Duroid 5880 with dielectric constant 10.2 and 2.2, respectively, by using standard photolithography process. Good results are obtained where the frequency responses exhibit that the filter successfully covers whole X-band frequencies by producing 44% bandwidth at 10.2 GHz center frequency with fifth-order Chebyshev response. Measured responses show good agreement with the simulated responses. The measured insertion loss for the multilayer filter is better than 2.5 dB, and the passband return loss is better than −12.4 dB. ©2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 448–450, 2010; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/mop.2491

LT-ViT: A Vision Transformer for multi-label Chest X-ray classification

Vision Transformers (ViTs) are widely adopted in medical imaging tasks, and some existing efforts have been directed towards vision-language training for Chest X-rays (CXRs). However, we envision that there still exists a potential for improvement in vision-only training for CXRs using ViTs, by aggregating information from multiple scales, which has been proven beneficial for non-transformer networks. Hence, we have developed LT-ViT, a transformer that utilizes combined attention between image tokens and randomly initialized auxiliary tokens that represent labels. Our experiments demonstrate that LT-ViT (1) surpasses the state-of-the-art performance using pure ViTs on two publicly available CXR datasets, (2) is generalizable to other pre-training methods and therefore is agnostic to model initialization, and (3) enables model interpretability without grad-cam and its variants.Comment: 5 pages, 2 figure

Microbial examination of drinking water supply systems of Elobeid city, Sudan

The present investigation was carried out to evaluate the microbial parameters of Elobeid drinking water supply systems, which comprise of Bara underground water system and the surface rainwater harvesting (RWH) system, during the period from July 2010–June 2011. Four samples from Bara and nine from RWH were collected. The microbial parameters were determined using different microbial techniques. The results showed that the mean total viable bacterial (TVC) and spore-forming bacteria counts in the RWH system were ranged as 80.26-1030.11 and 82.8-3479.8 cfu/ml, respectively and 4.67-110.5 and 0.83- 292.5 cfu/ml, respectively in Bara. Moreover, high counts of coliforms, faecal coliforms; faecal Streptococci, Salmonella, Staphylococci, Clostridia and Cyanobacteria were recorded in the RWH system, particularly during the rainy months (June–September), which not in agreement with international or local standards for drinking water. The predominant bacteria in the two water supply systems were Bacillus (6 species) Proteus mirabilis, Pseudomonas aeruginosa, Pseudomonas maltophilia, Enterobacter gergoviae, Enterobacter alvi, Proteus vulgaris, E. coli, Salmonella choleraesuis, Staphylococcus aureus, Streptococcus faecium and Streptococcus faecalis, in addition to many Cyanobacterial genera: Lyngbya, Microcystis, Oscillatoria, Synechocystis, Anabaena, Leptolyngbya, Dermocarpa, Aphanizomenon, Schizothrix and Phormidium. The presence of those harmful bacteria in water before and after treatment in the RWH system indicated that water treatment measures adopted by the North Kordofan State Water Corporation (coagulation, sand filtration and disinfection by chlorination) do not guarantee acceptable levels of water disinfection. To alleviate these problems, blending of the two water systems and subsequent treatments to reduce microbial load were suggested as recommended point of view. Published by the International journal of Microbiology and Mycology (IJMM