173 research outputs found

    ENAS-B: Combining ENAS with Bayesian Optimisation for Automatic Design of Optimal CNN Architectures for Breast Lesion Classification from Ultrasound Images

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    Efficient Neural Architecture Search (ENAS) is a recent development in searching for optimal cell structures for Convolutional Neural Network (CNN) design. It has been successfully used in various applications including ultrasound image classification for breast lesions. However, the existing ENAS approach only optimises cell structures rather than the whole CNN architecture nor its trainable hyperparameters. This paper presents a novel framework for automatic design of CNN architectures by combining strengths of ENAS and Bayesian Optimisation in two folds. Firstly, we use ENAS to search for optimal normal and reduction cells. Secondly, with the optimal cells and a suitable hyperparameter search space, we adopt Bayesian Optimisation to find the optimal depth of the network and optimal configuration of the trainable hyperparameters. To test the validity of the proposed framework, a dataset of 1,522 breast lesion ultrasound images is used for the searching and modelling. We then evaluate the robustness of the proposed approach by testing the optimized CNN model on three external datasets consisting of 727 benign and 506 malignant lesion images. We further compare the CNN model with the default ENAS-based CNN model, and then with CNN models based on the state-of-the-art architectures. The results (error rate of no more than 20.6% on internal tests and 17.3% on average of external tests) showed that the proposed framework generates robust and light CNN models

    Automatic Detection of Thyroid Nodule Characteristics From 2D Ultrasound Images

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    Thyroid cancer is one of the common types of cancer worldwide, and Ultrasound (US) imaging is a modality normally used for thyroid cancer diagnostics. The American College of Radiology Thyroid Imaging Reporting and Data System (ACR TIRADS) has been widely adopted to identify and classify US image characteristics for thyroid nodules. This paper presents novel methods for detecting the characteristic descriptors derived from TIRADS. Our methods return descriptions of the nodule margin irregularity, margin smoothness, calcification as well as shape and echogenicity using conventional computer vision and deep learning techniques. We evaluate our methods using datasets of 471 US images of thyroid nodules acquired from US machines of different makes and labeled by multiple radiologists. The proposed methods achieved overall accuracies of 88.00%, 93.18%, and 89.13% in classifying nodule calcification, margin irregularity, and margin smoothness respectively. Further tests with limited data also show a promising overall accuracy of 90.60% for echogenicity and 100.00% for nodule shape. This study provides an automated annotation of thyroid nodule characteristics from 2D ultrasound images. The experimental results showed promising performance of our methods for thyroid nodule analysis. The automatic detection of correct characteristics not only offers supporting evidence for diagnosis, but also generates patient reports rapidly, thereby decreasing the workload of radiologists and enhancing productivity

    A Fractional LC − RC Circuit

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    Mathematics Subject Classification: 26A33, 30B10, 33B15, 44A10, 47N70, 94C05We suggest a fractional differential equation that combines the simple harmonic oscillations of an LC circuit with the discharging of an RC circuit. A series solution is obtained for the suggested fractional differential equation. When the fractional order α = 0, we get the solution for the RC circuit, and when α = 1, we get the solution for the LC circuit. For arbitrary α we get a general solution which shows how the oscillatory behavior (LC circuit) go over to a decay behavior (RC circuit) as grows from 0 to 1, and vice versa. An explanation of the behavior is proposed based on the idea of the evolution of a resistive property in the inductor giving a new value to the inductance that affects the frequency of the oscillator

    Taming Anycast in a Wild Internet

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    Anycast is a popular tool for deploying global, widely available systems, including DNS infrastructure and content delivery networks (CDNs). The optimization of these networks often focuses on the deployment and management of anycast sites. However, such approaches fail to consider one of the primary configurations of a large anycast network: the set of networks that receive anycast announcements at each site (i.e., an announcement configuration). Altering these configurations, even without the deployment of additional sites, can have profound impacts on both anycast site selection and round-trip times. In this study, we explore the operation and optimization of any-cast networks through the lens of deployments that have a large number of upstream service providers. We demonstrate that these many-provider anycast networks exhibit fundamentally different properties when interacting with the Internet, having a greater number of single AS hop paths and reduced dependency on each provider, compared with few-provider networks. We further examine the impact of announcement configuration changes, demonstrating that in nearly 30% of vantage point groups, round-trip time performance can be improved by more than 25%, solely by manipulating which providers receive anycast announcements. Finally, we propose DailyCatch, an empirical measurement methodology for testing and validating announcement configuration changes, and demonstrate its ability to influence user-experienced performance on a global anycast CDN

    The Role of Television in Developing Creative and Innovative Ideas Among University Youth: A Field Study on a Sample of University Youth in the United Arab Emirates

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    University youth. Diagnosing young peoples motives in radio programs and diagnosis. The skills that young people see in their development and standing, and their interconnectedness in television in their marketing, especially since creativity and innovation are among the skills that can be cultivated in individuals, through a stage based on interesting scientific development that inspires creativity and innovation among young people, such as: competitions Scientific programs that stimulate the thinking process and puzzle programs related to the areas related to roads and military status. Developing scientific programs that motivate young people to develop their skills in developing their skills in developing their skills in developing their skills in project development and development programs. That is the essence of this study, which led us to the following results: The field results confirmed that 59% of the sample members believe that Arab programs contribute to marketing and developing creative and innovative skills for Arab youth, compared to 41% who believe in the contribution of foreign programs. Results related to the motives of exposure to programs concluded that 17% are motivated by acquiring new knowledge and scientific experiences, 11% are motivated by learning about the latest discoveries, 41.5% are exposed to learning innovative ways to solve problems, 18% are exposed to entertainment and leisure, and 10.5% are exposed to programs motivated by learning about peoples cultures, and 6% motivated by self- discovery

    Perspectives and attitudes of jordanian medical and paramedical students toward surrogate pregnancy

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    Purpose: This study aims at investigating the perspectives of Jordanian medical and paramedical students on surrogate pregnancy. Methods: A questionnaire-based cross-sectional study design was used. The sample consisted of n=328 students of both genders. The questionnaire responses were numerically coded and analyzed across gender and the level of education. Results: Approximately, 18% of the students reported good awareness about the ethical dilemmas of surrogacy. The results showed a general reluctance to accept surrogate pregnancy as the majority (80.5% of male students and 97.6% of female students) had a negative attitude toward surrogacy. In addition, undergraduate students were less supportive to surrogate pregnancy than graduate students. Religious considerations were the main reason (accounts for about 70%) for driving negative attitude toward surrogacy. Conclusion: The findings of the study indicate a general reluctance toward accepting the concept of surrogate pregnancy, which is mainly due to religious reasons

    Structural and Optoelectronic Characterization of Synthesized Undoped CZTS and Cd-doped CZTS Thin Films

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    138-149Copper zinc tin sulfide (CZTS) thin films with different doping ratios of Cadmium (Cd) were successfully fabricated using the sol-gel method by dip-coating technique. The surface morphology, the crystal structure properties as well the optical properties of undoped CZTS thin film and Cd- doped CZTS thin films were investigated using scanning electron microscopy (SEM), x-ray diffraction (XRD), and UV-Vis spectrophotometer. SEM micrographs demonstrated that the size and morphology of the particles improve due to increasing the Cd concentration in CZTS thin films. In addition, the XRD patterns exhibited the crystalline nature for CZTS thin films with kesterite crystal structure and showed improvement in some crystal structure properties such as crystal size and volume of unit cell with the incorporation of Cd into CZTS thin films. Moreover, optical bandgap energy , in addition to several optoelectronic parameters such as refractive index (), extinction coefficient (), dispersion energy, high-frequency dielectric constant, density of state, Plasma frequency, and relaxation time have been estimated. Remarkably, the bandgap energy of CZTS thin films ranges from 1.594 to 1.529 depending on the Cd content; it increases with increases the concentration of Cd into CZTS thin films

    NiO-Nanofillers Embedded in Graphite/PVA-Polymer Matrix for efficient Electromagnetic Radiation Shielding

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    In this study, we report on the preparation of NiO/graphite sheets nanofillers in PVA-polymer matrix using a simple cost-effective hydrothermal process for EM shielding effectiveness applications. The careful optimization of the growth conditions and NiO/G/PVA relative ratios have resulted in NiO nanoparticles formation with homogeneous density. In this nanocomposite, the NiO nanoparticles and graphite sheets were incorporated into a polymer to enhance the electromagnetic shielding effectiveness. The morphological, structural, and chemical analysis have been conducted by SEM, EDX and XRD techniques. EDX and XRD analysis confirmed the exact chemical composition with high purity. SEM images showed the best morphology with homogenous NiO-nanoparticles distribution on graphite sheets for 15 wt% NiO relative ratio NiO/G/PVA nanocomposite. The nanocomposite was tested in different environments and shielding chambers that contained relatively high-level exposure to electromagnetic radiation. The shielding effectiveness (SE) measurements of NiO/G/PVA showed a significant increase of shielding effectiveness of about 17 dB compared to the commercial shielding paint. This can be ascribed to the homogenous distribution of NiO-NPs over the entire graphite sheets and the strong interaction of the incident electromagnetic radiation with the magnetic and electric dipoles in the nanocomposite. These finding is promising for enhanced flexible and cost-effective EMI shielding applications

    Evaluation of the effect of hypericum triquetrifolium turra on memory impairment induced by chronic psychosocial stress in rats: Role of BDNF

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    Background: Chronic psychosocial stress impairs memory function and leads to a depression-like phenotype induced by a persistent status of oxidative stress. Hypericum perforatum L. (St. John’s wort) is widely used to relieve symptoms of anxiety and depression; however, its long-term use is associated with adverse effects. Hypericum triquetrifolium Turra is closely related to H. perforatum. Both plants belong to Hypericaceae family and share many biologically active compounds. Previous work by our group showed that methanolic extracts of H. triquetrifolium have potent antioxidant activity as well as high hypericin content, a component that proved to have stress-relieving and antidepressant effects by other studies. Therefore, we hypothesized that H. triquetrifolium would reduce stress-induced cognitive impairment in a rat model of chronic stress. Objective: To determine whether chronic treatment with H. triquetrifolium protects against stress-associated memory deficits and to investigate a possible mechanism. Methods: The radial arm water maze (RAWM) was used to test learning and memory in rats exposed to daily stress using the resident-intruder paradigm. Stressed and unstressed rats received chronic H. triquetrifolium or vehicle. We also measured levels of brain-derived neurotrophic factor (BDNF) in the hippocampus, cortex and cerebellum. Results: Neither chronic stress nor chronic H. triquetrifolium administration affected performance during acquisition. However, memory tests in the RAWM showed that chronic stress impaired different post-encoding memory stages. H. triquetrifolium prevented this impairment. Furthermore, hippocampal BDNF levels were markedly lower in stressed animals than in unstressed animals, and chronic administration of H triquetrifolium chronic administration protected against this reduction. No significant difference was observed in the effects of chronic stress and/or H. triquetrifolium treatment on BDNF levels in the cerebellum and cortex. Conclusion: H. triquetrifolium extract can oppose stress-associated hippocampus-dependent memory deficits in a mechanism that may involve BDNF in the hippocampus

    Optimization of facade design based on the impact of interior obstructions to daylighting

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    Overcrowding in the perimeter zone is an inevitable issue in residential rooms with limited space. Obstructions, such as furniture and household items, may block the existing windows, and therefore affect interior daylight conditions. A facade design approach is needed that simultaneously takes into account daylighting and the volume of usable space for obstructions in the perimeter zone of such rooms. This study simulates daylight distributions in a typical small residential room with obstructions in front of windows. The simulation consists of two parts. First, the effects on horizontal illuminances caused by different positions and shapes of obstructions are examined under an overcast sky. Second, the maximum usable space volumes for obstructions of 51 optimized facade configurations are calculated in terms of four window-to-wall ratios (WWRs). The results of this study show that optimizing the forms of facade design can increase the usable interior space volume and meet the daylighting requirements of Chinese standards for small residential rooms. Additionally, by using the optimized facade forms, a facade with a WWR value of 50% provides the maximum usable space for obstructions. Based on the above results, this paper presents two matrices that can help architects in selecting the appropriate fenestration methods and confirming the size of usable space and allocation for residents
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