20 research outputs found
High gain CPW‐fed UWB planar monopole antenna‐based compact uniplanar frequency selective surface for microwave imaging
YesIn this article, a novel uniplanar ultra‐wideband (UWB) stop frequency selective surface (FSS) was miniaturized to maximize the gain of a compact UWB monopole antenna for microwave imaging applications. The single‐plane FSS unit cell size was only 0.095λ × 0.095λ for a lower‐operating frequency had been introduced, which was miniaturized by combining a square‐loop with a cross‐dipole on FR4 substrate. The proposed hexagonal antenna was printed on FR4 substrate with coplanar waveguide feed, which was further backed at 21.6 mm by 3 × 3 FSS array. The unit cell was modeled with an equivalent circuit, while the measured characteristics of fabricated FSS array and the antenna prototypes were validated with the simulation outcomes. The FSS displayed transmission magnitude below −10 dB and linear reflection phase over the bandwidth of 2.6 to 11.1 GHz. The proposed antenna prototype achieved excellent gain improvement about 3.5 dBi, unidirectional radiation, and bandwidth of 3.8 to 10.6 GHz. Exceptional agreements were observed between the simulation and the measured outcomes. Hence, a new UWB baggage scanner system was developed to assess the short distance imaging of simulated small metallic objects in handbag model. The system based on the proposed antenna displayed a higher resolution image than the antenna without FSS
Classification of Cornel Arcus using Texture Features with Bayesian Regulation Back Propagation
The corneal arcus (CA) is an eye problem frequently faced by some group of people. The CA signs indicate the presence of abnormal lipid in blood and can cause several problems such as blood pressure, diabetes, and hyperlipidemia. This paper presents a comparison of classification of the abnormal eye using a neural network. In order to extract the image features, the gray level co-occurrence matrix (GLCM)was used. This matrix measures the texture of the image, where the statistical calculation can be used to present the image features. The Bayesian Regulation (BR) algorithm has been proposed, in which this classifier classifies the obtained results better than previous works by other researchers. In this experiment, two classes data-set of the eye image, normal and abnormal images CA are used. The results from this BR classifier demonstrate a sensitivity of 96.1 % and a specificity of 98.6 %. The overall accuracy of this proposed system is 97.6 %. Although this classifier does not obtain 100 % accuracy, however its result is proven to be able to classify the CA images successfully
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Diffusion tensor imaging parameters in mild traumatic brain injury and its correlation with early neuropsychological impairment: a longitudinal study
We explored the prognostic value of diffusion tensor imaging (DTI) parameters of selected white matter (WM) tracts in predicting neuropsychological outcome, both at baseline and 6 months later, among well-characterized patients diagnosed with mild traumatic brain injury (mTBI). Sixty-one patients with mTBI (mean age=27.08; standard deviation [SD], 8.55) underwent scanning at an average of 10 h (SD, 4.26) post-trauma along with assessment of their neuropsychological performance at an average of 4.35 h (SD, 7.08) upon full Glasgow Coma Scale recovery. Results were then compared to 19 healthy control participants (mean age=29.05; SD, 5.84), both in the acute stage and 6 months post-trauma. DTI and neuropsychological measures between acute and chronic phases were compared, and significant differences emerged. Specifically, chronic-phase fractional anisotropy and radial diffusivity values showed significant group differences in the corona radiata, anterior limb of internal capsule, cingulum, superior longitudinal fasciculus, optic radiation, and genu of corpus callosum. Findings also demonstrated associations between DTI indices and neuropsychological outcome across two time points. Our results provide new evidence for the use of DTI as an imaging biomarker and indicator of WM damage occurring in the context of mTBI, and they underscore the dynamic nature of brain injury and possible biological basis of chronic neurocognitive alterations
Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries
Background
Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.
Methods
This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries.
Results
In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.
Conclusion
This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries
Managing complications of radiation therapy in head and neck cancer patients: part VI. management of opportunistic infections
Head and neck cancer is becoming a more recognizable pathology to the general population and dentists. The modes of treatment include surgery and/or radiation therapy. Where possible, pretreatment dental assessment shall be provided for these patients before they undergo radiation therapy. There are occasions, however, whereby head and neck cancer patients are not prepared optimally for radiation therapy. Because of this, they succumb to complicated oral adverse effects after radiation therapy. The last part of this series reviews the opportunistic infections that can occur to the perioral structure. Their management is briefly discussed. © 2006 Elsevier. All rights reserved
Hybrid neural network for prediction of CO2 solubility in monoethanolamine and diethanolamine solutions
The solubility of CO2 in single monoethanolamine (MEA) and diethanolamine (DEA) solutions was predicted by a model developed based on the Kent-Eisenberg model in combination with a neural network. The combination forms a hybrid neural network (HNN) model. Activation functions used in this work were purelin, logsig and tansig. After training, testing and validation utilizing different numbers of hidden nodes, it was found that a neural network with a 3-15-1 configuration provided the best model to predict the deviation value of the loading input. The accuracy of data predicted by the HNN model was determined over a wide range of temperatures (0 to 120 °C), equilibrium CO2 partial pressures (0.01 to 6,895 kPa) and solution concentrations (0.5 to 5.0M). The HNN model could be used to accurately predict CO2 solubility in alkanolamine solutions since the predicted CO2 loading values from the model were in good agreement with experimental data
Hybrid computational scheme for antenna-human body interaction.
A new hybrid method of moments (MoM)/finite-difference time-domain (FDTD), with a sub-gridded finite-difference time-domain (SGFDTD) approach is presented. The method overcomes the drawbacks of homogeneous MoM and FDTD simulations, and so permits accurate analysis of realistic applications. As a demonstration, it is applied to the short-range interaction between an inhomogeneous human body and a small UHF RFID antenna tag, operating at 900 MHz. Near-field and far-field performance for the antenna are assessed for different placements over the body. The cumulative distribution function of the radiation efficiency and the absorbed power are presented and analyzed. The algorithm has a five-fold speed advantage over fine-gridded FDTD
Hybrid computational scheme for antenna-human body interaction.
A new hybrid method of moments (MoM)/finite-difference time-domain (FDTD), with a sub-gridded finite-difference time-domain (SGFDTD) approach is presented. The method overcomes the drawbacks of homogeneous MoM and FDTD simulations, and so permits accurate analysis of realistic applications. As a demonstration, it is applied to the short-range interaction between an inhomogeneous human body and a small UHF RFID antenna tag, operating at 900 MHz. Near-field and far-field performance for the antenna are assessed for different placements over the body. The cumulative distribution function of the radiation efficiency and the absorbed power are presented and analyzed. The algorithm has a five-fold speed advantage over fine-gridded FDTD
An investigation of border shopping development at Padang Besar
Padang Besar, a border town between the States of Malaysia and Thailand is well known for its shopping activities since early 1950s, with the establishment of shophouses along the border. However, the development and shopping
facilities offered to the visitors seem to be insufficient. Hence, the main objective of this paper is to provide some understanding on the development of border shopping scenario at Padang Besar. Grounded theory qualitative data
analysis strategy was employed in an attempt to generate the understanding of the border shopping development from the tourism supply chains perspective.The data was gathered through personal interviews and observations.The finding revealed that the town of Padang Besar does has a potential to be developed into a border shopping tourism
destination since the town itself is associated mainly with border shopping activities
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Directional and Isolated UWB-MIMO Antenna Based Uniplanar UWB-FSS Array and T-strip for Bi-static Microwave Imaging: Baggage-Scanner
YesThis article presented a novel compact multi-input-multi-output (MIMO) hexagonal monopole antenna with a uniplanar compact frequency-selective-surface (FSS) array for microwave imaging (MWI). The ultra-wideband (UWB) dual-element linear MIMO antenna was designed on the FR4 substrate with 50 Ω coplanar waveguide feed, T-strip isolation, novel numerical calculation, and equivalent circuit analyses. The main issues of realising high-resolution images based on planer UWB antenna for MWI are the low gain, omnidirectional pattern, design size, and mutual coupling of MIMO design. A novel technique was proposed to solve a hybrid issue (mutual coupling) of the MIMO reflected-waves from the FSS array and direct-wave. The uniplanar UWB-FSS unit cell was compacted by combining a square-loop and cross-dipole with a size of 0.095λ×0.095λ. The novel isolated UWB-MIMO antenna and UWB-FSS array (IMAF) were integrated, after investigating the distance between the antenna and FSS. The fabricated IMAF with a stable gain improvement of 4.5 dBi higher than the antenna without FSS, directional radiation pattern, size of 30×73.8×21.6 mm3 observed that a low mutual coupling of -27 dB, and operation bandwidth of 3.0-11.7 GHz. Moreover, a handbag was scanned experimentally via the bi-static approach to detect a small concealed object. The MWI system based on the MIMO antenna with FSS was displayed image resolution of 55% higher than that of MIMO antenna without FSS. The new baggage-scanner approach confirmed that the proposed MIMO antenna with FSS array can lead the humanity for healthy MWI applications.The full-text of this article will be released for public view at the end of the publisher embargo on 3rd Nov 2022