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Hydrodynamics and Heat Transfer Analysis of Airflow in a Sinusoidally Curved Channel

Computers, Materials & Continua 2022年第6期71卷 4835-4853页

作者： Abid.A.Memon M.Asif Memon kaleemullah bhatti Thanin Sitthiwirattham Nichaphat Patanarapeelert Department of Mathematics and Social Sciences Sukkur IBA UniversitySukkur65200SindhPakistan Mathematics Department Faculty of Science and TechnologySuan Dusit UniversityBangkok10300Thailand Department of Mathematics Faculty of Applied ScienceKing Mongkut’s University of Technology North BangkokBangkok10800Thailand

For heat transfer enhancement in heat exchangers,different types of channels are often *** performance of heat exchangers can be made better by considering geometry composed of sinusoidally curved *** research studies the modeling and simulation of airflow through a 2πunits long sinusoidally curved wavy *** the purpose,two-dimensional Navier Stokes equations along with heat equations are under *** simulate the fluid flow problem,the finite element-based software COMSOL Multiphysics 5.4 is *** parametric study for Reynolds number from Re=100 to Re=1000 and the period of vibration P from 0 to 5 are *** surface plots,streamline patterns,contours,and graphs are presented for the velocity field magnitude,temperature,and pressure against the Reynolds number as well as period of *** results are compared with various *** is found that due to the creation of periodic contraction regions the velocity magnitude of the flow is continuously increasing with the increase of Reynolds number,on the contrary the pressure is decreasing from inlet to outlet of the ***,a periodic variation in the pressure distribution along the vibrating boundaries has been found with an average increase of 500%for the high Reynolds number.A novel work was done by expressing the rotation rate per second in terms of local Reynolds number for the recirculating regions found due to the periodic oscillation of the *** average temperature near the outlet where a fixed temperature is imposed initially is decreasing with an increase in Reynolds *** convection process is weakened due to an increase of periodic vibration of boundaries.

关键词： Simulation of fluid flow heat transfer cosine function wavy channel

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Self-Awakened Particle Swarm Optimization BN Structure Learning Algorithm Based on Search Space Constraint

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Computers, Materials & Continua 2023年第9期76卷 3257-3274页

作者： kun Liu Peiran Li Yu Zhang Jia Ren Xianyu Wang Uzair Aslam bhatti School of Information and Communication Engineering Hainan UniversityHaikou570228China Playload Research Center for Space Electronic Information System Academy of Space Electronic Information TechnologyXi’an710100China Research Center CRSC Communication&Information Group Co.Ltd.Beijing100070China

To obtain the optimal Bayesian network(BN)structure,researchers often use the hybrid learning algorithm that combines the constraint-based(CB)method and the score-and-search(SS)*** hybrid method has the problemthat the search efficiency could be improved due to the ample search *** search process quickly falls into the local optimal solution,unable to obtain the global *** on this,the Particle SwarmOptimization(PSO)algorithm based on the search space constraint process is *** the first stage,the method uses dynamic adjustment factors to constrain the structure search space and enrich the diversity of the initial *** the second stage,the update mechanism is redefined,so that each step of the update process is consistent with the current structure which forms a one-to-one *** the same time,the“self-awakened”mechanism is added to prevent precocious particles frombeing part of the *** the fitness value of the particle converges prematurely,the activation operation makes the particles jump out of the local optimal values to prevent the algorithmfromconverging too quickly into the local ***,the standard network dataset was compared with other *** experimental results showed that the algorithmcould find the optimal solution at a small number of iterations and a more accurate network structure to verify the algorithm’s effectiveness.

关键词： Bayesian network structure learning particle swarm optimization

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Simulation of Non-Isothermal Turbulent Flows Through Circular Rings of Steel

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Computers, Materials & Continua 2022年第3期70卷 4341-4355页

作者： Abid.A.Memon M.Asif Memon kaleemullah bhatti kamsing Nonlaopon Ilyas khan Department of Mathematics and Social Sciences Sukkur IBA UniversitySukkur65200SindhPakistan Department of Mathematics Faculty of ScienceKhon Kaen UniversityKhon Kaen40002Thailand Department of Mathematics College of Science Al-ZulfiMajmaah UniversityAl-Majmaah11952Saudi Arabia

This article is intended to examine the fluid flow patterns and heat transfer in a rectangular channel embedded with three semi-circular cylinders comprised of steel at the *** an organization is used to generate the heat exchangers with tube and shell because of the production of more turbulence due to zigzag path which is in favor of rapid heat *** of little maintenance,the heat exchanger of such type is extensively ***,we generate simulation of flow and heat transfer using nonisothermal flow interface in the Comsol multiphysics 5.4 which executes the Reynolds averaged Navier stokes equation(RANS)model of the turbulent flow together with heat *** is tested with Prandtl number(Pr=0.7)with inlet velocity magnitude in the range from 1 to 2 m/sec which generates the Reynolds number in the range of 2.2×10^(5) to 4.4×10^(5) with turbulence kinetic energy and the dissipation rate in ranges(3.75×10^(−3) to 1.5×10^(−2))and(3.73×10^(−3)−3×10^(−2))*** correlations available in the literature are used in order to check *** results are displayed through streamlines,surface plots,contour plots,isothermal lines,and *** is concluded that by retaining such an arrangement a quick distribution of the temperature over the domain can be seen and also the velocity magnitude is increasing from 333.15%to a maximum of 514%.The temperature at the middle shows the consistency in value but declines immediately at the *** process becomes faster with the decrease in inlet velocity magnitude.

关键词： Incompressible turbulent flow heat transfer non-isothermal finite element method energy equation

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Framework for fault-tolerant speed tracking control of gasoline engines using the first principle-based engine model

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Journal of Control and Decision 2023年第4期10卷 560-571页

作者： Raheel Anjum Ahmed Yar Ghulam Murtaza Qadeer Ahmed Aamer I.bhatti Controls and Signal Processing Research Group(CASPR) Capital University of Science and TechnologyIslamabadPakistan Department of Mechanical Engineering College of E&MENational University of Sciences and TechnologyIslamabadPakistan Center for Automotive Research The Ohio State UniversityColumbusOHUSA Department of Electrical Engineering Capital University of Science and TechnologyIslamabadPakistan

Optimal engine torque management,a fundamental objective,depends predominantly on engine speed tracking *** ensures to attain desired speed profile in the presence of uncertainties,disturbances and *** the other hand,certain requirements such as emissions control,fuel efficiency and drivability are degraded in case of poorspeed ***,constraints on engine speed tracking performance are even more stringent for hybrid power-train architecture as crankshaft speed and engine torque are the basic variables for coordinated *** tracking is also considered essential for gearshift control ofthe automatic *** this research work,a framework for fault-tolerant speed tracking of the gasoline engine is proposed using the First Principle-based Engine Model(FPEM).A high-fidelity direct relationship between fuel injection input and engine speed is derived by the transformation of *** is induced in the fuel injection subsystem to generate the torque *** the proposed framework,a second-order sliding mode-based control technique is applied to track desired speed profile by mitigating the faultsin the fuel injection *** data acquired from the engine test rig is used to demonstrate the offline validity and fault tolerance capabilities of the proposed framework in MATLAB/Simulink.

关键词： Engine speed tracking fault-tolerant control gasoline engines sliding mode control

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Zero Watermarking Algorithm for Medical Image Based on Resnet50-DCT

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Computers, Materials & Continua 2023年第4期75卷 293-309页

作者： Mingshuai Sheng Jingbing Li Uzair Aslam bhatti Jing Liu Mengxing Huang Yen-Wei Chen School of Information and Communication Engineering Hainan UniversityHaikou570228China State key Laboratory of Marine Resource Utilization in the South China Sea Hainan UniversityHaikou570228China School of Computer Science and Technology Hainan UniversityHaikou570228China Research Center for Healthcare Data Science Zhejiang LabHangzhou311121China Graduate School of Information Science and Engineering Ritsumeikan UniversityKyoto5258577Japan

Medical images are used as a diagnostic tool, so protecting theirconfidentiality has long been a topic of study. From this, we propose aResnet50-DCT-based zero watermarking algorithm for use with medicalimages. To begin, we use Resnet50, a pre-training network, to draw out thedeep features of medical images. Then the deep features are transformedby DCT transform and the perceptual hash function is used to generatethe feature vector. The original watermark is chaotic scrambled to get theencrypted watermark, and the watermark information is embedded into theoriginal medical image by XOR operation, and the logical key vector isobtained and saved at the same time. Similarly, the same feature extractionmethod is used to extract the deep features of the medical image to be testedand generate the feature vector. Later, the XOR operation is carried outbetween the feature vector and the logical key vector, and the encryptedwatermark is extracted and decrypted to get the restored watermark;thenormalized correlation coefficient (NC) of the original watermark and therestored watermark is calculated to determine the ownership and watermarkinformation of the medical image to be tested. After calculation, most ofthe NC values are greater than 0.50. The experimental results demonstratethe algorithm’s robustness, invisibility, and security, as well as its ability toaccurately extract watermark information. The algorithm also shows goodresistance to conventional attacks and geometric attacks.

关键词： Medical images deep residual network resnet50-DCT privacy protection robustness security

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Robust Multi-Watermarking Algorithm for Medical Images Based on GoogLeNet and Henon Map

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Computers, Materials & Continua 2023年第4期75卷 565-586页

作者： Wenxing Zhang Jingbing Li Uzair Aslam bhatti Jing Liu Junhua Zheng Yen-Wei Chen School of Information and Communication Engineering Hainan UniversityHaikou570228China State key Laboratory of Marine Resource Utilization in the South China Sea Hainan UniversityHaikou570228China Research Center for Healthcare Data Science Zhejiang LabHangzhou311100China Graduate School of Information Science and Engineering Ritsumeikan UniversityKusatsu525-8577Japan

The field of medical images has been rapidly evolving since the advent of the digital medical information ***,medical data is susceptible to leaks and hacks during *** paper proposed a robust multi-watermarking algorithm for medical images based on GoogLeNet transfer learning to protect the privacy of patient data during transmission and storage,as well as to increase the resistance to geometric attacks and the capacity of embedded watermarks of watermarking ***,a pre-trained GoogLeNet network is used in this paper,based on which the parameters of several previous layers of the network are fixed and the network is fine-tuned for the constructed medical dataset,so that the pre-trained network can further learn the deep convolutional features in the medical dataset,and then the trained network is used to extract the stable feature vectors of medical ***,a two-dimensional Henon chaos encryption technique,which is more sensitive to initial values,is used to encrypt multiple different types of watermarked private ***,the feature vector of the image is logically operated with the encrypted multiple watermark information,and the obtained key is stored in a third party,thus achieving zero watermark embedding and blind *** experimental results confirmthe robustness of the algorithm from the perspective ofmultiple types of watermarks,while also demonstrating the successful embedding ofmultiple watermarks for medical images,and show that the algorithm is more resistant to geometric attacks than some conventional watermarking algorithms.

关键词： Zero watermarks GoogLeNet medical image Henon map feature vector

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Raising capital amid economic policy uncertainty:an empirical investigation

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Financial Innovation 2022年第1期8卷 2013-2044页

作者： Dawood Ashraf Mohsin khawaja M.Ishaq bhatti Islamic Development Bank Institute(A Member of Islamic Development Bank Group) 8111 King Khalid StreetJeddah 22332-2444Saudi Arabia School of Business Studies Institute of Business Administration(IBA)KarachiPakistan S P Jain School of Global Management SydneyNSW 2141Australia La Trobe Business School La Trobe UniversityMelbourneAustralia

This paper investigates how economic policy uncertainty affects firms’frequency and their choice of financial instruments to raise *** applying a three-step sequential framework over a sample of 6834 publicly listed US non-financial firms,we find that during periods of high economic uncertainty,firms raise capital more frequently with a preference toward debt *** empirical findings suggest that firms prefer debt financing over equity financing to avoid ownership dilution and high equity *** rise in leverage during periods of high economic uncertainty highlights the importance of scrutinizing policy tools used to stabilize the economy during such times.

关键词： Economic policy uncertainty Political uncertainty Capital issuance Debt and equity markets Ownership structure Governance mechanisms

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A Multi-Watermarking Algorithm for Medical Images Using Inception V3 and DCT

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Computers, Materials & Continua 2023年第1期74卷 1279-1302页

作者： Yu Fan Jingbing Li Uzair Aslam bhatti Chunyan Shao Cheng Gong Jieren Cheng Yenwei Chen School of Information and Communication Engineering Hainan UniversityHaikou570100China State key Laboratory of Marine Resource Utilization in the South China Sea Hainan UniversityHaikou570100China School of Computer Science and Technology Hainan UniversityHaikou570100China Graduate School of Information Science and Engineering Ritsumeikan UniversityKyoto5258577Japan Hainan Blockchain Technology Engineering Research Center Hainan UniversityHaikou570100China TJ-YZ School of Network Science Haikou University of EconomicsHaikou571127China

Medical images are a critical component of the diagnostic process for *** the quality of medical photographs is essential to the accuracy of a physician’s diagnosis,they must be encrypted due to the characteristics of digital storage and information leakage associated with medical *** watermark embedding algorithm embeds the watermark information into the medical image,which reduces the quality of the medical image and affects the physicians’judgment of patient *** addition,watermarks in this method have weak robustness under high-intensity geometric attacks when the medical image is attacked and the watermarks are *** paper proposes a novel watermarking algorithm using the convolutional neural networks(CNN)Inception V3 and the discrete cosine transform(DCT)to address above mentioned ***,the medical image is input into the Inception V3 network,which has been structured by adjusting parameters,such as the size of the convolution kernels and the typical architecture of the convolution ***,the coefficients extracted from the fully connected layer of the network are transformed by DCT to obtain the feature vector of the medical *** last,the watermarks are encrypted using the logistic map system and hash function,and the keys are stored by a third *** encrypted watermarks and the original image features are performed logical operations to realize the embedding of *** the experimental section,multiple watermarking schemes using three different types of watermarks were implemented to verify the effectiveness of the three proposed *** NC values for all the images are more than 90%accurate which shows the robustness of the *** experimental results demonstrate the robustness under both conventional and high-intensity geometric attacks of the proposed algorithm.

关键词： Inception V3 multi-watermarking DCT watermark encryption robustness

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A Progressive Approach to Generic Object Detection: A Two-Stage Framework for Image Recognition

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Computers, Materials & Continua 2023年第6期75卷 6351-6373页

作者： Muhammad Aamir Ziaur Rahman Waheed Ahmed Abro Uzair Aslam bhatti Zaheer Ahmed Dayo Muhammad Ishfaq College of Computer Science Huanggang Normal UniversityHuanggangHubei438000China FAST School of Computing National University of Computer&Emerging Science(NUCES)Karachi CampusKarachi75030Pakistan School of Information and Communication Engineering Hainan UniversityHaikou68000China

Object detection in images has been identified as a critical area of research in computer vision image *** has developed several novel methods for determining an object’s location and category from an ***,there is still room for improvement in terms of detection *** study aims to develop a technique for detecting objects in *** enhance overall detection performance,we considered object detection a two-fold problem,including localization and *** proposed method generates class-independent,high-quality,and precise proposals using an agglomerative clustering *** then combine these proposals with the relevant input image to train our network on convolutional ***,a network refinement module decreases the quantity of generated proposals to produce fewer high-quality candidate ***,revised candidate proposals are sent into the network’s detection process to determine the object *** algorithm’s performance is evaluated using publicly available the PASCAL Visual Object Classes Challenge 2007(VOC2007),VOC2012,and Microsoft Common Objects in Context(MS-COCO)*** only 100 proposals per image at intersection over union((IoU)=0.5 and 0.7),the proposed method attains Detection Recall(DR)rates of(93.17%and 79.35%)and(69.4%and 58.35%),and Mean Average Best Overlap(MABO)values of(79.25%and 62.65%),for the VOC2007 and MS-COCO datasets,***,it achieves a Mean Average Precision(mAP)of(84.7%and 81.5%)on both VOC *** experiment findings reveal that our method exceeds previous approaches in terms of overall detection performance,proving its effectiveness.

关键词： Deep neural network deep learning features agglomerative clustering localizations refinement region of interest(ROI) object detection

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Defending Adversarial Examples by a Clipped Residual U-Net Model

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Intelligent Automation & Soft Computing 2023年第2期35卷 2237-2256页

作者： kazim Ali Adnan N.Qureshi Muhammad Shahid bhatti Abid Sohail Mohammad Hijji Department of Computer Science Faculty of Information TechnologyUniversity of Central Punjab Lahore54000Pakistan Department of Computer Science COMSAT University IslamabadLahore CampusLahore54000Pakistan Faculty of Computers and Information Technology Computer Science DepartmentUniversity of TabukTabuk47711Saudi Arabia

Deep learning-based systems have succeeded in many computer vision ***,it is found that the latest study indicates that these systems are in danger in the presence of adversarial *** attacks can quickly spoil deep learning models,e.g.,different convolutional neural networks(CNNs),used in various computer vision tasks from image classiﬁcation to object *** adversarial examples are carefully designed by injecting a slight perturbation into the clean *** proposed CRU-Net defense model is inspired by state-of-the-art defense mechanisms such as MagNet defense,Generative Adversarial Net-work Defense,Deep Regret Analytic Generative Adversarial Networks Defense,Deep Denoising Sparse Autoencoder Defense,and Condtional Generattive Adversarial Network *** have experimentally proved that our approach is better than previous defensive *** proposed CRU-Net model maps the adversarial image examples into clean images by eliminating the adversarial *** proposed defensive approach is based on residual and U-Net *** experiments are done on the datasets MNIST and CIFAR10 to prove that our proposed CRU-Net defense model prevents adversarial example attacks in WhiteBox and BlackBox settings and improves the robustness of the deep learning algorithms especially in the computer visionﬁ*** have also reported similarity(SSIM and PSNR)between the original and restored clean image examples by the proposed CRU-Net defense model.

关键词： Adversarial examples adversarial attacks defense method residual learning u-net cgan cru-et model

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