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1.
Sci Rep ; 14(1): 9501, 2024 04 25.
Artigo em Inglês | MEDLINE | ID: mdl-38664436

RESUMO

The use of various kinds of magnetic resonance imaging (MRI) techniques for examining brain tissue has increased significantly in recent years, and manual investigation of each of the resulting images can be a time-consuming task. This paper presents an automatic brain-tumor diagnosis system that uses a CNN for detection, classification, and segmentation of glioblastomas; the latter stage seeks to segment tumors inside glioma MRI images. The structure of the developed multi-unit system consists of two stages. The first stage is responsible for tumor detection and classification by categorizing brain MRI images into normal, high-grade glioma (glioblastoma), and low-grade glioma. The uniqueness of the proposed network lies in its use of different levels of features, including local and global paths. The second stage is responsible for tumor segmentation, and skip connections and residual units are used during this step. Using 1800 images extracted from the BraTS 2017 dataset, the detection and classification stage was found to achieve a maximum accuracy of 99%. The segmentation stage was then evaluated using the Dice score, specificity, and sensitivity. The results showed that the suggested deep-learning-based system ranks highest among a variety of different strategies reported in the literature.


Assuntos
Neoplasias Encefálicas , Imageamento por Ressonância Magnética , Redes Neurais de Computação , Humanos , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/diagnóstico , Imageamento por Ressonância Magnética/métodos , Aprendizado Profundo , Glioma/diagnóstico por imagem , Glioma/patologia , Glioma/diagnóstico , Glioblastoma/diagnóstico por imagem , Glioblastoma/diagnóstico , Glioblastoma/patologia , Processamento de Imagem Assistida por Computador/métodos , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Interpretação de Imagem Assistida por Computador/métodos
2.
Biomimetics (Basel) ; 8(5)2023 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-37754143

RESUMO

High-strength grout is specified to increase the bond between grout and bar in grouted connections and to ensure that the forces in the bars can be transferred to the surrounding material accordingly. Although polymer grout is fast setting and rapid in strength development, the use of polymer mortar in grouted connections is still limited because of the lack of information and familiarity practitioners have regarding the product. The goal of this work is to investigate the mechanical characteristics and performance of polyester grout containing fly ash that can be used as an infill material for grouted connections. This study focused on the composition of polymer grout, which typically consists of a binder, hardener, and filler. In this particular case, the binder was made of unsaturated polyester resin and hardener, while the filler was fine sand. The aim of the research was to investigate the potential benefits of incorporating fly ash as an additional filler in polymer resin grout and examine the mechanical properties of polymer resin grout. To this end, varying amounts of fly ash were added to the mix, ranging from 0% to 32% of the total filler by volume, with a fixed polymer content of 40%. The performance of the resulting grout was evaluated through flowability, compression, and splitting tensile tests. The results of the experiments showed that, at a fly ash volume of 28%, the combination of fine sand and fly ash led to an improvement in grout strength; specifically, at this volume of fly ash, the compressive and tensile strengths increased by 24.7% and 124%, respectively, compared to the control mix. However, beyond a fly ash volume of 28%, the mechanical properties of the grout started to deteriorate. Due its superior properties in terms of compressive and flexural strengths over all examined mixes, the PRG-40-28 mix is ideal for use in the infill material for mechanical connections.

3.
Opt Express ; 30(21): 37816-37832, 2022 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-36258363

RESUMO

The security issue is essential in the Internet-of-Things (IoT) environment. Biometrics play an important role in securing the emerging IoT devices, especially IoT robots. Biometric identification is an interesting candidate to improve IoT usability and security. To access and control sensitive environments like IoT, passwords are not recommended for high security levels. Biometrics can be used instead, but more protection is needed to store original biometrics away from invaders. This paper presents a cancelable multimodal biometric recognition system based on encryption algorithms and watermarking. Both voice-print and facial images are used as individual biometrics. Double Random Phase Encoding (DRPE) and chaotic Baker map are utilized as encryption algorithms. Verification is performed by estimating the correlation between registered and tested models in their cancelable format. Simulation results give Equal Error Rate (EER) values close to zero and Area under the Receiver Operator Characteristic Curve (AROC) equal to one, which indicates the high performance of the proposed system in addition to the difficulty to invert cancelable templates. Moreover, reusability and diversity of biometric templates is guaranteed.

4.
Materials (Basel) ; 15(9)2022 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-35591399

RESUMO

Utilizing solid wastes and industrial by-products as a partial replacement for raw materials has become an acceptable practice among researchers and scientists in the civil engineering field. Sawdust and wood shavings are not an exception; they are being used in concrete as a partial or total replacement for some of its constituents. The main goal of this research is to establish a relation between destructive and non-destructive testing for concrete containing wood shavings as a partial replacement of sand (woodcrete). With this type of material existing, thus the need to understand the behavior of such material becomes urgent and evokes the need to ease the process of the assessment and the evaluation of such materials and therefore provide more understanding of its behavior. In addition to the conventional concrete mix, five mixes of woodcrete were made by replacing fine aggregate by volume with wood shavings at different replacement levels varied from 5% to 50%. Cubic samples were tested at the age of 90 days using nondestructive tests (NDT), namely, rebound hammer test and ultrasonic pulse velocity test. Then, the specimens were tested using a conventional compressive test using a universal compression testing machine. Statistical analysis was performed to establish empirical relations between destructive and non-destructive results. The dynamic modulus of elasticity was calculated, and some formulas to estimate the (compressive) strength of woodcrete using NDT results were proposed and tested against experimental results and showed acceptable results.

5.
Appl Opt ; 61(4): 875-883, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-35201055

RESUMO

Two schemes for optical wireless modulation format recognition (MFR), based on the orthogonal-triangular decomposition (OTD) and Hough transform (HT) of the constellation diagrams, are proposed in this paper. Constellation diagrams are obtained at optical signal-to-noise ratios (OSNRs) ranging from 5 to 30 dB for seven different modulation formats (2/4/8/16-PSK and 8/16/32-QAM) as images. The first scheme depends on applying the HT of the obtained images; the second scheme is based on utilization of the decomposition of each of the obtained image matrices into an orthogonal matrix (Q) and an upper triangular matrix (R) followed by the HT. Different classifiers, including AlexNet, VGG16, and VGG19, are used for the MFR task. Model setups and results are provided to study the scheme efficiency at different levels of OSNR. The proposed schemes provide unique signatures for constellation diagrams. Moreover, it reveals that the main pattern corresponding to each constellation diagram is more distinguishable for both proposed schemes at different levels of OSNR. The obtained results achieve high accuracy at low OSNR values.

6.
Int J Numer Method Biomed Eng ; 38(1): e3530, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34506081

RESUMO

Deep learning is one of the most promising machine learning techniques that revolutionalized the artificial intelligence field. The known traditional and convolutional neural networks (CNNs) have been utilized in medical pattern recognition applications that depend on deep learning concepts. This is attributed to the importance of anomaly detection (AD) in automatic diagnosis systems. In this paper, the AD is performed on medical electroencephalography (EEG) signal spectrograms and medical corneal images for Internet of medical things (IoMT) systems. Deep learning based on the CNN models is employed for this task with training and testing phases. Each input image passes through a series of convolution layers with different kernel filters. For the classification task, pooling and fully-connected layers are utilized. Computer simulation experiments reveal the success and superiority of the proposed models for automated medical diagnosis in IoMT systems.


Assuntos
Inteligência Artificial , Redes Neurais de Computação , Simulação por Computador , Internet , Aprendizado de Máquina
7.
Appl Opt ; 60(30): 9380-9389, 2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34807076

RESUMO

High-speed wireless communication is necessary in our personal lives, in both working and living spaces. This paper presents a scheme for wireless optical modulation format recognition (MFR) based on the Hough transform (HT). The HT is used to project constellation diagrams onto another space for efficient feature extraction. Constellation diagrams are obtained at optical signal-to-noise ratios (OSNR) ranging from 5 to 30 dB for eight different modulation formats (2/4/8/16 phase-shift keying and 8/16/32/64 QAM). Different classifiers are used for the task of MFR: AlexNet, VGG16, and VGG19. A study of the effect of varying the number of samples on the accuracy of the classifiers is provided for each modulation format. To evaluate the proposed scheme, the efficiency of the three classifiers is studied at different values of OSNR. The obtained results reveal that the proposed scheme succeeds in identifying the wireless optical modulation format blindly with a classification accuracy up to 100%, even at low OSNR values less than 10 dB.

8.
Appl Opt ; 60(13): 3659-3667, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33983298

RESUMO

This paper presents a new trend in biometric security systems, which is cancelable multi-biometrics. In general, traditional biometric systems depend on a single biometric for identification. These traditional systems are subject to different types of attacks. In addition, a biometric signature may be lost in hacking scenarios; for example, in the case of intrusion, biometric signatures can be stolen forever. To reduce the risk of losing biometric signatures, the trend of cancelable biometrics has evolved by using either deformed or encrypted versions of biometrics for verification. In this paper, several biometric traits for the same person are treated to obtain a single cancelable template. First, optical scanning holography (OSH) is applied during the acquisition of each biometric. The resulting outputs are then compressed simultaneously to generate a unified template based on the energy compaction property of the discrete cosine transform (DCT). Hence, the OSH is used in the proposed approach as a tool to generate deformed versions of human biometrics in order to get the unified biometric template through DCT compression. With this approach, we guarantee the possibility of using multiple biometrics of the same user to increase security, as well as privacy of the new biometric template through utilization of the OSH. Simulation results prove the robustness of the proposed cancelable multi-biometric approach in noisy environments.


Assuntos
Biometria/métodos , Segurança Computacional , Compressão de Dados/métodos , Holografia/métodos , Simulação por Computador , Dermatoglifia , Mãos , Humanos , Iris , Curva ROC
9.
Appl Opt ; 60(13): 3977-3988, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33983337

RESUMO

Underwater localization using visible-light communications is proposed based on neural networks (NNs) estimation of received signal strength (RSS). Our proposed work compromises two steps: data collection and NN training. First, data are collected with the aid of Zemax OpticStudio Monte Carlo ray tracing software, where we configure 40,000 receivers in a $100\;{\rm m} \times 100\;{\rm m}$ area in order to measure the channel gain for each detector in seawater. The channel gains represent the input data set to the NN, while the output of the NN is the coordinates of each detector based on the RSS intensity technique. Next, an NN system is built and trained with the aid of Orange data mining software. Several trials for NN implementations are performed, and the best training algorithms, activation functions, and number of neurons are determined. In addition, several performance measures are considered in order to evaluate the robustness of the proposed network. Specifically, we evaluate the following parameters: classification accuracy (CA), area under the curve (AUC), training time, testing time, F1, precision, recall, logloss, and specificity. The corresponding measures are as follows: 99.1% for AUC and 98.7% for CA, F1, precision, and recall. Further, the performance results of logloss and specificity are 7.3% and 99.3% respectively.

10.
Int J Numer Method Biomed Eng ; 37(8): e3449, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33599091

RESUMO

Brain tumor is a mass of anomalous cells in the brain. Medical imagining techniques have a vital role in the diagnosis of brain tumors. Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) techniques are the most popular techniques to localize the tumor area. Brain tumor segmentation is very important for the diagnosis of tumors. In this paper, we introduce a framework to perform brain tumor segmentation, and then localize the region of the tumor, accurately. The proposed framework begins with the fusion of MR and CT images by the Non-Sub-Sampled Shearlet Transform (NSST) with the aid of the Modified Central Force Optimization (MCFO) to get the optimum fusion result from the quality metrics perspective. After that, image interpolation is applied to obtain a High-Resolution (HR) image from the Low-Resolution (LR) ones. The objective of the interpolation process is to enrich the details of the fusion result prior to segmentation. Finally, the threshold and the watershed segmentation are applied sequentially to localize the tumor region, clearly. The proposed framework enhances the efficiency of segmentation to help the specialists diagnose brain tumors.


Assuntos
Algoritmos , Neoplasias Encefálicas , Encéfalo/diagnóstico por imagem , Neoplasias Encefálicas/diagnóstico por imagem , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Tomografia Computadorizada por Raios X
11.
Microsc Res Tech ; 84(3): 394-414, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33350559

RESUMO

Automatic detection of maculopathy disease is a very important step to achieve high-accuracy results for the early discovery of the disease to help ophthalmologists to treat patients. Manual detection of diabetic maculopathy needs much effort and time from ophthalmologists. Detection of exudates from retinal images is applied for the maculopathy disease diagnosis. The first proposed framework in this paper for retinal image classification begins with fuzzy preprocessing in order to improve the original image to enhance the contrast between the objects and the background. After that, image segmentation is performed through binarization of the image to extract both blood vessels and the optic disc and then remove them from the original image. A gradient process is performed on the retinal image after this removal process for discrimination between normal and abnormal cases. Histogram of the gradients is estimated, and consequently the cumulative histogram of gradients is obtained and compared with a threshold cumulative histogram at certain bins. To determine the threshold cumulative histogram, cumulative histograms of images with exudates and images without exudates are obtained and averaged for each type, and the threshold cumulative histogram is set as the average of both cumulative histograms. Certain histogram bins are selected and thresholded according to the estimated threshold cumulative histogram, and the results are used for retinal image classification. In the second framework in this paper, a Convolutional Neural Network (CNN) is utilized to classify normal and abnormal cases.


Assuntos
Retinopatia Diabética , Disco Óptico , Doenças Retinianas , Algoritmos , Retinopatia Diabética/diagnóstico por imagem , Humanos , Redes Neurais de Computação , Doenças Retinianas/diagnóstico por imagem
12.
Magn Reson Imaging ; 61: 300-318, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31173851

RESUMO

The successful early diagnosis of brain tumors plays a major role in improving the treatment outcomes and thus improving patient survival. Manually evaluating the numerous magnetic resonance imaging (MRI) images produced routinely in the clinic is a difficult process. Thus, there is a crucial need for computer-aided methods with better accuracy for early tumor diagnosis. Computer-aided brain tumor diagnosis from MRI images consists of tumor detection, segmentation, and classification processes. Over the past few years, many studies have focused on traditional or classical machine learning techniques for brain tumor diagnosis. Recently, interest has developed in using deep learning techniques for diagnosing brain tumors with better accuracy and robustness. This study presents a comprehensive review of traditional machine learning techniques and evolving deep learning techniques for brain tumor diagnosis. This review paper identifies the key achievements reflected in the performance measurement metrics of the applied algorithms in the three diagnosis processes. In addition, this study discusses the key findings and draws attention to the lessons learned as a roadmap for future research.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Diagnóstico por Computador/métodos , Aprendizado de Máquina , Imageamento por Ressonância Magnética , Algoritmos , Encéfalo/patologia , Neoplasias Encefálicas/patologia , Glioma/diagnóstico por imagem , Glioma/patologia , Humanos , Processamento de Imagem Assistida por Computador/métodos
13.
AMB Express ; 7(1): 111, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28582970

RESUMO

During the last few years, the global transcription machinery engineering (gTME) technique has gained more attention as an effective approach for the construction of novel mutants. Genetic strategies (molecular biology methods) were utilized to get mutational for both genes (SPT15 and TAF23) basically existed in the Saccharomyces cerevisiae genome via screening the gTME approach in order to obtain a new mutant S. cerevisiae diploid strain. The vector pYX212 was utilized to transform these genes into the control diploid strain S. cerevisiae through the process of mating between haploids control strains S. cerevisiae (MAT-a [CICC 1374]) and (MAT-α [CICC 31144]), by using the oligonucleotide primers SPT15-EcoRI-FW/SPT15-SalI-RV and TAF23-SalI-FW/TAF23-NheI-RV, respectively. The resultant mutants were examined for a series of stability tests. This study showed how strong the effect of using strategic gTME with the importance of the modification we conducted in Error Prone PCR protocol by increasing MnCl2 concentration instead of MgCl2. More than ninety mutants we obtained in this study were distinguished by a high level production of bio-ethanol as compared to the diploid control strain.

14.
J Biotechnol ; 186: 91-7, 2014 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-25011099

RESUMO

The aproteinogenic amino acid L-phenylglycine (L-Phg) is an important side chain building block for the preparation of several antibiotics and taxol. To biosynthesis L-Phg from glucose, an engineered Escherichia coli containing L-Phg synthetic genes was firstly developed by an L-phenylalanine producing chassis supplying phenylpyruvate. The enzymes HmaS (L-4-hydroxymandelate synthase), Hmo (L-4-hydroxymandelate oxidase) and HpgT (L-4-hydroxyphenylglycine transaminase) from Amycolatopsis orientalis as well as Streptomyces coelicolor were heterologously expressed in E. coli and purified to evaluate their abilities on L-Phg formation. HpgT conversing phenylglyoxylate to L-Phg uses an unusual amino donor L-phenylalanine, which releases another phenylpyruvate as the substrate of HmaS. Thus, a recycle reaction was developed to maximize the utilization of precursor phenylpyruvate. To amplify the accumulation of L-Phg, the effects of attenuating L-phenylalanine transamination was investigated. After deletion of tyrB and aspC, L-Phg yield increased by 12.6-fold. The limiting step in the L-Phg biosynthesis was also studied; the L-Phg yield was further improved by 14.9-fold after enhancing hmaS expression. Finally, by optimizing expression of hmaS, hmo and hpgT and attenuation of L-phenylalanine transamination, the L-Phg yield was increased by 224-fold comparing with the original strain.


Assuntos
Escherichia coli/genética , Glicina/análogos & derivados , Proteínas Recombinantes/metabolismo , Transaminases/metabolismo , Actinomycetales/enzimologia , Actinomycetales/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Escherichia coli/metabolismo , Glucose/metabolismo , Glicina/análise , Glicina/metabolismo , Redes e Vias Metabólicas , Fenilalanina/metabolismo , Proteínas Recombinantes/genética , Streptomyces/enzimologia , Streptomyces/genética , Transaminases/genética
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