Some new nonlinear weakly singular integral inequalities of wendroff type with applications

Some new weakly singular integral inequalities of Wendroff type are established, which generalized some known weakly singular inequalities for functions in two variables and can be used in the analysis of various problems in the theory of certain classes of integral equations and evolution equations. Application examples are also given.published_or_final_versio

An ultrathin and flexible terahertz electromagnetically induced transparency-like metasurface based on asymmetric resonators

Terahertz (THz) electromagnetically induced transparency-like (EIT-like) metasurfaces have been extensively explored and frequently used for sensing, switching, slow light, and enhanced nonlinear effects. Reducing radiation and non-radiation losses in EIT-like systems contributes to increased electromagnetic (EM) field confinement, higher transmission peak magnitude, and Q-factor. This can be accomplished by the use of proper dielectric properties and engineering novel designs. Therefore, we fabricated a THz EIT-like metasurface based on asymmetric metallic resonators on an ultra-thin and flexible dielectric substrate. Because the quadruple mode is stimulated in a closed loop, an anti-parallel surface current forms, producing a transparency window with a transmission peak magnitude of 0.8 at 1.96 THz. To control the growing trend of EIT-like resonance, the structure was designed with four asymmetry levels. The effect of the substrate on the resonance response was also explored, and we demonstrated experimentally how the ultra-thin substrate and the metasurface asymmetric novel pattern contributed to higher transmission and lower loss

A new adaptive interpolation algorithm for 3D ultrasound imaging with speckle reduction and edge preservation

Author name used in this publication: Qinghua HuangAuthor name used in this publication: Yongping ZhengAuthor name used in this publication: Minhua Lu2008-2009 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe

Superpixel-based Two-view Deterministic Fitting for Multiple-structure Data

This paper proposes a two-view deterministic geometric model fitting method, termed Superpixel-based Deterministic Fitting (SDF), for multiple-structure data. SDF starts from superpixel segmentation, which effectively captures prior information of feature appearances. The feature appearances are beneficial to reduce the computational complexity for deterministic fitting methods. SDF also includes two original elements, i.e., a deterministic sampling algorithm and a novel model selection algorithm. The two algorithms are tightly coupled to boost the performance of SDF in both speed and accuracy. Specifically, the proposed sampling algorithm leverages the grouping cues of superpixels to generate reliable and consistent hypotheses. The proposed model selection algorithm further makes use of desirable properties of the generated hypotheses, to improve the conventional fit-and-remove framework for more efficient and effective performance. The key characteristic of SDF is that it can efficiently and deterministically estimate the parameters of model instances in multi-structure data. Experimental results demonstrate that the proposed SDF shows superiority over several state-of-the-art fitting methods for real images with single-structure and multiple-structure data.Comment: Accepted by European Conference on Computer Vision (ECCV

An optical coherence tomography (OCT)-based air jet indentation system for measuring the mechanical properties of soft tissues

2008-2009 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe

PCR and microarray analysis of AmpC and ESBLs producing Pseudomonas aeruginosa isolates from intensive care units

Detection of AmpC and ESBL producing P. aeruginosa by phenotypic methods is challenging, especially in low-income countries such as Pakistan. Therefore, a molecular method was developed for rapid detection of these resistance markers. A total of 303 clinical samples were collected from intensive care units (ICUs) of the Jinnah postgraduate medical centre (JPMC) Karachi, Pakistan. The isolates were identified by traditional and matrix-assisted laser desorption ionization–time-of-flight mass spectrometry (MALDI-TOF-MS). Isolates were phenotypically analyzed for AmpCs and ESBL by D-test and by double disc synergy, respectively. The Check MDR CT103 XL and PCR techniques were used for the detection AmpCs and ESBLs. Out of 303 isolates, 148 (48.8%) were P. aeruginosa. The resistance pattern of P. aeruginosa against piperacillin, cefatizidime and cefepime was 59.4%, 64.8% and 59.4% respectively. More than 60% isolates were resistant to aminoglycosides and ciprofloxacin. All (148) strains were found sensitive to colistin. Phenotypic ESBL prevalence was 8.8% whereas genotypic resistance was 29.1%. bla was the most prevalent ESBL. Although 25.67% of P. aeruginosa isolates were positive phenotypically for AmpC, microarray (Check-MDR) analysis did not detect chromosomally located AmpC in any of the isolates. VE

Reducing the number of elements in the synthesis of a broadband linear array with multiple simultaneous frequency-invariant beam patterns

© 2018 IEEE. The problem of reducing the number of elements in a broadband linear array with multiple simultaneous crossover frequency-invariant (FI) patterns is considered. Different from the single FI pattern array case, every element channel in the multiple FI pattern array is divided and followed by multiple finite-impulse-response (FIR) filters, and each of the multiple FIR filters has a set of coefficients. In this situation, a collective filter coefficient vector and its energy bound are introduced for each element, and then the problem of reducing the number of elements is transformed as minimizing the number of active collective filter coefficient vectors. In addition, the radiation characteristics including beam pointing direction, mainlobe FI property, sidelobe level, and space-frequency notching requirement for each of the multiple patterns can be formulated as multiple convex constraints. The whole synthesis method is implemented by performing an iterative second-order cone programming (SOCP). This method can be considered as a significant extension of the original SOCP for synthesizing broadband sparse array with single FI pattern. Numerical synthesis results show that the proposed method by synthesizing multiple discretized crossover FI patterns can save more elements than the original iterative SOCP by using a single continuously scannable FI pattern for covering the same space range. Moreover, even for multiple FI-patterns case with complicated space-frequency notching, the proposed method is still effective in the reduction of the number of elements

Hypernetworks for sound event detection: a proof-of-concept

Polyphonic sound event detection (SED) involves the prediction of sound events present in an audio recording along with their onset and offset times. Recently, Deep Neural Networks, specifically convolutional recurrent neural networks (CRNN) have achieved impressive results for this task. The convolution part of the architecture is used to extract translational invariant features from the input and the recurrent part learns the underlying temporal relationship between audio frames. Recent studies showed that the weight sharing paradigm of recurrent networks might be a hindering factor in certain kinds of time series data, specifically where there is a temporal conditional shift, i.e. the conditional distribution of a label changes across the temporal scale. This warrants a relevant question - is there a similar phenomenon in polyphonic sound events due to dynamic polyphony level across the temporal axis? In this work, we explore this question and inquire if relaxed weight sharing improves performance of a CRNN for polyphonic SED. We propose to use hypernetworks to relax weight sharing in the recurrent part and show that the CRNN’s performance is improved by ~3% across two datasets, thus paving the way for further exploration of the existence of temporal conditional shift for polyphonic SED

Modified simple cold storage of rat livers with UW solution

Rat livers were preserved with the conventional use of UW solution for 30,42, and 48 hr and compared with livers in which the vascular bed was expanded with an additional 10 to 60 ml UW/100 g liver. The extra UW, expressed as % liver weight, was entrapped during final portal infusion by tying off the supra- and infrahepatic inferior vena cava. A beneficial influence of the vascular expansion was most pronounced in the 40% group, with 10/10, 5/10, and 3/10 long-term survivors following transplantation after 30, 42, and 48 hr preservation versus 3/10 and 0/10 after 30 and 42 hr in the 0c/c controls. In separate experiments, surrogate indi-ces of preservation quality following reperfusion explained this effect. The 40%—and, to a lesser extent, 20%—livers had higher and more uniformly distributed portal blood flow, better tissue oxygenation, smaller increases in postperfusion liver enzymes, higher adenine nucleotides and energy charge, and less histopathologic evidence of hemorrhage and congestion. Pressure changes in the vena cava fluid sump in additional experiments indicated that retrograde infusion of the trapped UW solution occurred in all of the 10-60% groups during the first 6 hr with stable pressures of 1.5 to 3 cm H20 thereafter. Collectively, these data suggest that the much discussed selective vulnerability of the microvasculature of stored allografts is due in part (or principally) to its selective lack of long-term exposure to the UW solution, which drains out of the open vessels but not from the parenchyma. The potential clinical exploitation of this concept is discussed. © 1994 by Williams and Wilkins

Multidomain pseudospectral time-domain simulations of scattering by objects buried in lossy media

A multidomain pseudospectral time-domain (PSTD) method with a newly developed well-posed PML is introduced as an accurate and flexible tool for the modeling of electromagnetic scattering by 2-D objects buried in an inhomogeneous lossy medium. Compared with the previous single-domain Fourier PSTD method, this approach allows for an accurate treatment of curved geometries with subdomains, curvilinear mapping, and high-order Chebyshev polynomials. The effectiveness of the algorithm is confirmed by an excellent agreement between the numerical results and analytical solutions for perfectly conducting as well as permeable dielectric cylinders. The algorithm has been applied to model various ground-penetrating radar (GPR) applications involving curved objects in a lossy half space with an undulating surface. This multidomain PSTD algorithm is potentially a very useful tool for simulating antennas near complex objects and inhomogeneous media