A quantum convolutional neural network on NISQ devices

Quantum machine learning is one of the most promising applications of quantum computing in the noisy intermediate-scale quantum (NISQ) era. We propose a quantum convolutional neural network(QCNN) inspired by convolutional neural networks (CNN), which greatly reduces the computing complexity compared with its classical counterparts, with O((log2M)6) basic gates and O(m2+e) variational parameters, where M is the input data size, m is the filter mask size, and e is the number of parameters in a Hamiltonian. Our model is robust to certain noise for image recognition tasks and the parameters are independent on the input sizes, making it friendly to near-term quantum devices. We demonstrate QCNN with two explicit examples. First, QCNN is applied to image processing, and numerical simulation of three types of spatial filtering, image smoothing, sharpening, and edge detection is performed. Secondly, we demonstrate QCNN in recognizing image, namely, the recognition of handwritten numbers. Compared with previous work, this machine learning model can provide implementable quantum circuits that accurately corresponds to a specific classical convolutional kernel. It provides an efficient avenue to transform CNN to QCNN directly and opens up the prospect of exploiting quantum power to process information in the era of big data.

One size fits all?: Modeling face-mask fit on population-based faces

The use of face masks by the general population during viral outbreaks such as the COVID-19 pandemic, although at times controversial, has been effective in slowing down the spread of the virus. The fit of simple cloth masks on the face as well as the resulting perimeter leakage and face mask efficacy are expected to be highly dependent on the type of mask and facial topology. However, this effect has to date, not been examined and quantified. Here, we study the leakage of a rectangular cloth mask on a large virtual population of subjects with diverse facial features, using computational mechanics modeling. The effect of weight, age, gender, and height on the leakage is studied. The Centers for Disease Control and Prevention (CDC) recommended mask size was used as a basis for comparison and was found not to be the most effective design for all subjects. Thin, feminine, and young faces benefit from mask sizes smaller than that recommended by the CDC. The results show that side-edge tuck-in of the masks could lead to a larger localized gap opening in many face categories, and is therefore not recommended for all. The perimeter leakage from the face mask worn by thin/feminine faces is mostly from the leakage area along the bottom edge of the mask and therefore, a tuck-in of the bottom edge of the mask or a mask smaller than the CDC recommended mask size are proposed as a more effective design. The leakage from the top edge of the mask is determined to be largely unaffected by mask size and tuck-in ratio, meaning that other mechanical alterations such as a nose wire strip are necessary to reduce the leakage at this site.

Development of a smart-fit system for CPAP interface selection

Continuous Positive Airway Pressure (CPAP) therapy is commonly prescribed for longstanding, acute cases of Obstructive Sleep Apnea (OSA) during which patients must wear a tight-fitting breathing mask overnight for the duration of the treatment. Because this condition frequently leads to the permanent use of CPAP masks, interface selection is a crucial factor influencing the treatment quality and effectiveness. Masks/interface selection is normally performed on a trial an error basis with clinicians informing their selection based on OSA-related factors with basic fitting feedback from patients. However, it is not uncommon for patients to abandon the treatment or request additional consultations due to ill-fitting CPAP mask with the main sources of discomfort being perceived air leakage and mask/strap overtightening leading to skin damage. This work introduces a novel system (Smart-Fit), for CPAP interface selection using advanced digital technologies, such as Reverse Engineering and Computational Modeling (Finite Element Analysis) which are paired to evaluate and determine the best fitting interface for each clinical case. The model simplifies the number of 3D facial landmarks to 12 and established that a 2 mm scan resolution is enough for accurate scans. The Von Mises stress map in ANSYS serves as an indicator of potential high-pressure areas, triggering the need for a chance of mask size. Current results indicate the Smart Fit System can enable a “best fit CPAP interface” to be selected considering individual’s physical characteristics and existing CPAP interface configurations. The development of the Smart Fit System is an evolution compared to traditional CPAP interface selection approach, which optimizes the CPAP interface selection process.

The AMBRE Project: Spectrum normalisation influence on Mg abundances in the metal-rich Galactic disc

Context. The abundance of α-elements provides an important fossil signature in Galactic archaeology to trace the chemical evolution of the different disc populations. High-precision chemical abundances are crucial to improving our understanding of the chemodynamical properties present in the Galaxy. However, deriving precise abundance estimations in the metal-rich disc ([M/H] > 0 dex) is still challenging. Aims. The aim of this paper is to analyse different error sources affecting magnesium abundance estimations from optical spectra of metal-rich stars. Methods. We derived Mg abundances for 87522 high-resolution spectra of 2210 solar neighbourhood stars from the AMBRE Project, and selected the 1172 best parametrised stars with more than four repeated spectra. For this purpose, the GAUGUIN automated abundance estimation procedure was employed. Results. The normalisation procedure has a strong impact on the derived abundances, with a clear dependence on the stellar type and the line intensity. For non-saturated lines, the optimal wavelength domain for the local continuum placement should be evaluated using a goodness-of-fit criterion, allowing mask-size dependence with the spectral type. Moreover, for strong saturated lines, applying a narrow normalisation window reduces the parameter-dependent biases of the abundance estimate, increasing the line-to-line abundance precision. In addition, working at large spectral resolutions always leads to better results than at lower ones. The resulting improvement in the abundance precision makes it possible to observe both a clear thin-thick disc chemical distinction and a decreasing trend in the magnesium abundance even at supersolar metallicities. Conclusions. In the era of precise kinematical and dynamical data, optimising the normalisation procedures implemented for large spectroscopic stellar surveys would provide a significant improvement to our understanding of the chemodynamical patterns of Galactic populations.

Correlation and variation of cuff inflating volumes and pressures in different adult models of laryngeal mask: a prospective randomized trial

Background: Hyperinflation of laryngeal mask cuffs may carry the risk of airway complications. The manufacturer recommends inflating cuff until the intracuff pressure reaches 60 cmH2O, or inflate with the volume of air to not exceed the maximum recommended volume. We prospectively assessed the correlation of cuff inflating volumes and pressures, and the appropriated the cuff inflating volumes to generate an intracuff pressure of 60 cmH2O in the adult laryngeal masks from different manufacturers. Methods: Two groups of eighty patients requiring laryngeal mask size 3 and 4 during general anesthesia were randomized into 4 subgroups for each size of the laryngeal mask: Soft Seal® (Portex®), AuraOnceTM (Ambu®), LMA-ClassicTM (Teleflex®) and LMA-ProSealTM (Teleflex®). After insertion, the cuff was inflated with 5-ml increments of air up to the maximum recommended volume. After each 5-ml intracuff pressure was measured, the volume of air that generated the intracuff pressure of 60 cmH2O was recorded. Results: Mean(SD) volume of air required to achieve the intracuff pressure of 60 cmH2O in Soft Seal®, AuraOnceTM, LMA-ClassicTM, LMA-ProSealTM laryngeal mask size 3 were 11.80(1.88), 9.20(1.88), 8.95(1.50) and 13.50(2.48) ml, respectively, and these volumes in laryngeal mask size 4 were 14.45(4.12), 12.55(1.85), 11.30(1.95) and 18.20(3.47) ml, respectively. The maximum recommended volume resulted in high intracuff pressures (>60 cmH2O) in all laryngeal mask types and sizes studied. Conclusion: Pressure-volume curves of adult laryngeal masks are all in sigmoidal shape. Cuff designs and materials can effect pressure and volume correlation. Approximately half of the maximum recommended volume is required to achieve the intracuff pressure of 60 cmH2O except LMA-ProSealTM which required two-thirds of the maximum recommended volume. Trial registration: Thai Clinical Trials Registry, TCTR20150602001, May 28, 2015

Preliminary study of improved median filter using adaptively mask size in light microscopic image

This study aimed to develop and evaluate an improved median filter (IMF) with an adaptive mask size for light microscope (LM) images. We acquired images of the mouse first molar using a LM at 100× magnification. The images obtained using our proposed IMF were compared with those from a conventional median filter. Several parameters such as the contrast-to-noise ratio, coefficient of variation, no-reference assessments and peak signal-to-noise ratio were employed to evaluate the image quality quantitatively. The results demonstrated that the proposed IMF could effectively de-noise the LM images and preserve the image details, achieving a better performance than the conventional median filter.

Correlation and variation of cuff inflating volumes and pressures in different adult models of laryngeal mask airway: a prospective randomized trial

Background : Hyperinflation of laryngeal mask cuffs may carry the risk of airway complications. The manufacturer recommends inflating cuff until the intracuff pressure reaches 60 cmH 2 O, or inflate with the volume of air to not exceed the maximum recommended volume. We prospectively assessed the correlation of cuff inflating volumes and pressures, and the appropriated the cuff inflating volumes to generate an intracuff pressure of 60 cmH 2 O in the adult laryngeal masks from different manufacturers. Methods : Two groups of eighty patients requiring laryngeal mask size 3 and 4 during general anesthesia were randomized into 4 subgroups for each size of the laryngeal mask: Soft Seal ® (Portex ® ), AuraOnce TM (Ambu ® ), LMA-Classic TM (Teleflex ® ) and LMA-ProSeal TM (Teleflex ® ). After insertion, the cuff was inflated with 5-ml increments of air up to the maximum recommended volume. After each 5-ml intracuff pressure was measured, the volume of air that generated the intracuff pressure of 60 cmH 2 O was recorded . Results : Mean(SD) volume of air required to achieve the intracuff pressure of 60 cmH 2 O in Soft Seal ® , AuraOnce TM , LMA-Classic TM , LMA-ProSeal TM laryngeal mask size 3 were 11.80(1.88), 9.20(1.88), 8.95(1.50) and 13.50(2.48) ml, respectively, and these volumes in laryngeal mask size 4 were 14.45(4.12), 12.55(1.85), 11.30(1.95) and 18.20(3.47) ml, respectively. The maximum recommended volume resulted in high intracuff pressures (>60 cmH 2 O) in all laryngeal mask types and sizes studied. Conclusion : Pressure-volume curves of adult laryngeal masks are all in sigmoidal shape. Cuff designs and materials can effect pressure and volume correlation. Approximately half of the maximum recommended volume is required to achieve the intracuff pressure of 60 cmH 2 O except LMA-ProSeal TM which required two-thirds of the maximum recommended volume. Trial registration: Thai Clinical Trials Registry, TCTR20150602001, May 28, 2015