检索结果-南通市图书馆

一种优化开关磁阻电机换相区控制策略的高效率转矩分配函数

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

电工技术学报 2024年第6期39卷 1671-1683页

作者：杨帆陈昊李晓东 Miguel Pablo Aguirre muhammad asghar Saqib 中国矿业大学电气工程学院徐州221116 新能源电动车技术与装备中东欧国家国际联合研究中心徐州221008 江苏省高校新能源发电与电动车国际合作联合实验室徐州221008 徐州市新能源电动车技术与装备重点实验室徐州221008 澳门科技大学创新工程学院中国澳门999078 布宜诺斯艾利斯工学院电子工程系布宜诺斯艾利斯B1636 巴基斯坦工程技术大学电气工程系讷瓦布沙阿44000

转矩分配函数被广泛应用于抑制开关磁阻电机的转矩脉动。然而,输入相转矩跟踪不足或者输出相产生较大的负转矩这两种情况通常会导致电机的转矩脉动难以得到有效抑制,并降低电机的运行效率。因此,为了能够有效降低电机的转矩脉动并提高... 详细信息

转矩分配函数被广泛应用于抑制开关磁阻电机的转矩脉动。然而,输入相转矩跟踪不足或者输出相产生较大的负转矩这两种情况通常会导致电机的转矩脉动难以得到有效抑制,并降低电机的运行效率。因此,为了能够有效降低电机的转矩脉动并提高电机的效率,提出了一种新型的转矩分配函数控制策略。在提出的转矩分配函数控制策略中,电机的换相区域分为两个区域。在前一区域中,通过降低输入相转矩分配的比例,可以实现输入相实际转矩快速跟踪参考转矩,电机的转矩脉动有效降低。同时由于在输入相电感变化率较低时减少输入相分配的转矩,从而输入相的峰值电流随之降低,电机的转矩电流比提高。在后一区域中,将输出相的电流在转子对齐位置附近处减小到0,以避免产生较大的负转矩。因此,在所提出的方案下,电机的转矩脉动得到有效抑制,电机的效率也得到了提高。为了验证该方法的有效性,在一台12/8三相开关磁阻电机上进行了仿真和实验。结果表明,所提出的转矩分配函数控制策略能有效降低开关磁阻电机转矩脉动,也能有效地提高开关磁阻电机的运行效率。

关键词：开关磁阻电机转矩分配函数负转矩转矩电流比效率

Long-term outcomes of titanium-nitride-oxide coated stents and drug-eluting stents in acute coronary syndrome:A systematic review and meta-analysis

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

World Journal of Cardiology 2024年第5期16卷 293-305页

作者： muhammad Ahmed Ali Fahim Afia Salman Hira Anas Khan Syed muhammad Hasan Muskan FatimaBhojani Sarah Aslam Amna Zia Ul Haq Vishal Reddy Bejugam Beena Muntaha Nasir Wajiha Gul Abdul Moeed Abdelrahman S Abdalla muhammad Majid muhammad Sohaib asghar Md Al Hasibuzzaman Department of Internal Medicine Dow University of Health SciencesKarachi 74200Pakistan Department of Internal Medicine North Central Bronx HospitalBronxNY 10467United States Department of Urology Center for Academic MedicineStanford University School of MedicinePalo AltoCA 33872United States Department of Cardiovascular Imaging Cleveland ClinicClevelandOH 44195United States Division of Nephrology and Hypertension Mayo Clinic RochesterRochesterMN 55905United States Institute of Nutrition and Food Science University of DhakaDhaka 1000Bangladesh

BACKGROUND In severe cases of coronary artery disease,percutaneous coronary intervention provide promising *** stent used could be a drug-eluting stent(DES)or a titanium-nitride-oxide coated stent(TiNOS).AIM To compare the 5-year effectiveness and safety of the two stent *** The following systematic review and meta-analysis was conducted in accordance with the preferred reporting items for systematic reviews and meta-analysis guidelines,and PubMed/MEDLINE,Scopus,and Cochrane Central were searched from inception till August *** outcomes were major adverse cardiac events(MACE),cardiac death,myocardial infarction(MI),cardiac death or MI,and ischemia-driven total lesion revascularization(ID-TLR).RESULTS Four randomized controlled trials(RCT),which analyzed a sum total of 3045 patients with acute coronary syndrome(ACS)after a median follow-up time of 5 years were *** statistically insignificant,an increase in the ID-TLR was observed in patients receiving TiNOSs vs *** addition,MI,cardiac death and MI,and definite stent thrombosis(DST)were significantly decreased in the TiNOS *** analysis revealed no significant results with meta-regression presenting non-ST elevated MI(NSTEMI)as a statistically significant covariate in the outcome of *** TiNOS was found to be superior to DES in terms of MI,cardiac death or MI,and DST outcomes,however,the effect of the two stent types on ID-TLR and MACE was not significant.A greater number of studies are required to establish an accurate comparison of patient outcomes in TiNOS and DES.

关键词： Stents Drug-eluting Major adverse cardiac events All-cause death Meta-analysis

An Access Control Scheme Using Heterogeneous Signcryption for IoT Environments

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2022年第3期70卷 4307-4321页

作者： Insaf Ullah Hira Zahid Fahad Algarni muhammad asghar Khan Hamdard Institute of Engineering and Technology Islamabad44000Pakistan Department of Information Technology Abbottabad University of Science and TechnologyAbbottabadPakistan College of Computing and Information Technology The University of BishaBishaSaudi Arabia

When the Wireless Sensor Network(WSN)is combined with the Internet of Things(IoT),it can be employed in a wide range of applications,such as agriculture,industry 4.0,health care,smart homes,among *** the big data generated by these applications in Cloud Servers(CSs),requires higher levels of authenticity and confidentiality during communication conducted through the *** is one of the most promising approaches nowadays for overcoming such obstacles,due to its combined nature,i.e.,signature and encryption.A number of researchers have developed schemes to address issues related to access control in the IoT literature,however,the majority of these schemes are based on homogeneous *** will be neither adequate nor practical for heterogeneous IoT *** addition,these schemes are based on bilinear pairing and elliptic curve cryptography,which further requires additional processing time and more communication overheads that is inappropriate for real-time ***,this paper aims to solve the above-discussed issues,we proposed an access control scheme for IoT environments using heterogeneous signcryption scheme with the efficiency and security hardiness of hyperelliptic *** the security services such as replay attack prevention,confidentiality,integrity,unforgeability,non-repudiations,and forward secrecy,the proposed scheme has very low computational and communication costs,when it is compared to existing *** is primarily because of hyperelliptic curve lighter nature of key and other *** AVISPA tool is used to simulate the security requirements of our proposed scheme and the results were under two backbends(Constraint Logic-based Attack Searcher(CL-b-AtSER)and On-the-Fly Model Checker(ON-t-FL-MCR))proved to be SAFE when the presented scheme is coded in HLPSL *** scheme was proven to be capable of preventing a variety of attacks,including confidentiality,integrity,unforge

关键词： Internet of Things(IoT) access control big data heterogeneous signcryption

An Efficient Proxy Blind Signcryption Scheme for IoT

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2022年第3期70卷 4293-4306页

作者： Aamer Khan Insaf Ullah Fahad Algarni muhammad Naeem M.Irfan Uddin muhammad asghar Khan Department of Information Technology Abbottabad University of Science and TechnologyAbbotabadPakistan Hamdard Institute of Engineering and Technology Islamabad44000Pakistan College of Computing and Information Technology University of BishaBishaSaudi Arabia Institute of Computing Kohat University of Science and TechnologyKohatPakistan

Recent years have witnessed growing scientific research interest in the Internet of Things(IoT)technologies,which supports the development of a variety of applications such as health care,Industry 4.0,agriculture,ecological data management,and other various *** utilizes the Internet as a prime medium of communication for both single documents as well as multi-digital ***,due to the wide-open nature of the Internet,it is important to ensure the anonymity,untraceably,confidentiality,and unforgeability of communication with efficient computational complexity and low *** designed a light weight and secure proxy blind signcryption for multi-digital messages based on a hyperelliptic curve(HEC).Our results outperform the available schemes in terms of computational cost and communication *** designed scheme also has the desired authentication,unforgeability of warrants and/or plaintext,confidentiality,integrity,and blindness,***,our scheme is more suitable for devices with low computation power such as mobiles and tablets.

关键词： Proxy signcryption multi-digital-documents proxy blind signcryption hyperelliptic curve IoT

The Double Edge Sword Based Distributed Executor Service

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computer Systems Science & Engineering 2022年第8期42卷 589-604页

作者： Faisal Bahadur Arif Iqbal Umar Insaf Ullah Fahad Algarni muhammad asghar Khan Department of Information Technology Hazara UniversityMansehra21300Pakistan Hamdard Institute of Engineering and Technology Islamabad 44000Pakistan College of Computing and Information Technology The University of BishaBishaSaudi Arabia

Scalability is one of the most important quality attribute of softwareintensive systems,because it maintains an effective performance parallel to the large fluctuating and sometimes unpredictable *** order to achieve scalability,thread pool system(TPS)(which is also known as executor service)has been used extensively as a middleware service in software-intensive *** optimization is a challenging problem that determines the optimal size of thread pool dynamically on *** case of distributed-TPS(DTPS),another issue is the load balancing b/w available set of TPSs running at backend *** DTPSs are overloaded either due to an inappropriate TPS optimization strategy at backend servers or improper load balancing scheme that cannot quickly recover an ***,the performance of software-intensive system is ***,in this paper,we propose a new DTPS that follows the collaborative round robin load balancing that has the effect of a double-edge *** the one hand,it effectively performs the load balancing(in case of overload situation)among available TPSs by a fast overload recovery procedure that decelerates the load on the overloaded TPSs up to their capacities and shifts the remaining load towards other gracefully running *** on the other hand,its robust load deceleration technique which is applied to an overloaded TPS sets an appropriate upper bound of thread pool size,because the pool size in each TPS is kept equal to the request rate on it,hence dynamically optimizes *** evaluated the results of the proposed system against state of the art DTPSs by a clientserver based simulator and found that our system outperformed by sustaining smaller response times.

关键词： Software-intensive systems distributed executor service load balancing overload monitoring multi-threading thread pool performance

Ambiguity Resolution in Direction of Arrival Estimation with Linear Antenna Arrays Using Differential Geometry

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2022年第1期70卷 581-599页

作者： Alamgir Safi muhammad asghar Khan Fahad Algarni muhammad Adnan Aziz M.Irfan Uddin Insaf Ullah Tanweer Ahmad Cheema Department of Electronic Engineering ISRA UniversityIslamabad44000Pakistan Hamdard Institute of Engineering&Technology Islamabad44000Pakistan College of Computing and Information Technology University of BishaBishaSaudi Arabia Institute of Computing Kohat University of Science and TechnologyKohatPakistan

Linear antenna arrays(LAs)can be used to accurately predict the direction of arrival(DOAs)of various targets of interest in a given ***,under certain conditions,LA suffers from the problem of ambiguities among the angles of targets,which may result inmisinterpretation of such *** order to cope up with such ambiguities,various techniques have been ***,none of them fully resolved such a problem because of rank deficiency and high computational *** aimed to resolve such a problem by proposing an algorithm using differential *** proposed algorithm uses a specially designed doublet antenna array,which is made up of two individual linear *** angle observation models,ambiguous observation model(AOM)and estimated observation model(EOM),are derived for each individual *** ambiguous set of angles is contained in the AOM,which is obtained from the corresponding array elements using differential *** EOM for each array,on the other hand,contains estimated angles of all sources impinging signals on each array,as calculated by a direction-finding algorithm such as the genetic *** algorithm then contrasts the EOM of each array with its AOM,selecting the output of that array whose EOM has the minimum correlation with its corresponding *** comparison to existing techniques,the proposed algorithm improves estimation accuracy and has greater precision in antenna aperture selection,resulting in improved resolution capabilities and the potential to be used more widely in practical *** simulation results using MATLAB authenticates the effectiveness of the proposed algorithm.

关键词： Antenna array direction of arrival ambiguity resolution doublet antenna array ambiguous observation model estimated observation model

A Lightweight and Robust User Authentication Protocol with User Anonymity for IoT-Based Healthcare

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2022年第4期131卷 307-329页

作者： Chien-Ming Chen Shuangshuang Liu Shehzad Ashraf Chaudhry Yeh-Cheng Chen muhammad asghar khan College of Computer Science and Engineering Shandong University of Science and TechnologyQingdao266590China Department of Computer Engineering Istanbul Gelisim UniversityIstanbul34310Turkey Department of Computer Science University of CaliforniaDavisCA95616USA Department of Electrical Engineering Hamdard UniversityIslamabad44000Pakistan

With the rise of the Internet of Things(IoT),the word“intelligent medical care”has increasingly become a major *** medicine adopts the most advanced IoT technology to realize the interaction between patients and people,medical institutions,andmedical ***,with the openness of network transmission,the security and privacy of information transmission have become a major ***,Masud et *** a lightweight anonymous user authentication protocol for IoT medical treatment,claiming that their method can resist various ***,through analysis of the protocol,we observed that their protocol cannot effectively resist privileged internal attacks,sensor node capture attacks,and stolen authentication attacks,and their protocol does not have perfect forward ***,we propose a new protocol to resolve the security vulnerabilities in Masud’s protocol and remove some redundant parameters,so as tomake the protocolmore compact and *** addition,we evaluate the security and performance of the new protocol and prove that the overall performance of the new protocol is better than that of other related protocols.

关键词： IoT intelligent medical user authentication

Speech Recognition-Based Automated Visual Acuity Testing with Adaptive Mel Filter Bank

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2022年第2期70卷 2991-3004页

作者： Shibli Nisar muhammad asghar Khan Fahad Algarni Abdul Wakeel M.Irfan Uddin Insaf Ullah Department of Electrical Engineering National University of Sciences and Technology(NUST)Islamabad44000Pakistan Hamdard Institute of Engineering&Technology Islamabad44000Pakistan College of Computing and Information Technology University of BishaBishaSaudi Arabia Institute of Computing Kohat University of Science and TechnologyKohatPakistan

One of the most commonly reported disabilities is vision loss,which can be diagnosed by an ophthalmologist in order to determine the visual system of a *** procedure,however,usually requires an appointment with an ophthalmologist,which is both time-consuming and expensive *** issues that can arise include a lack of appropriate equipment and trained practitioners,especially in rural *** on a cognitively motivated attribute extraction and speech recognition approach,this paper proposes a novel idea that immediately determines the eyesight *** proposed system uses an adaptive filter bank with weighted mel frequency cepstral coefficients for feature *** adaptive filter bank implementation is inspired by the principle of spectrum sensing in cognitive radio that is aware of its environment and adapts to statistical variations in the input stimuli by learning from the *** performance evaluation demonstrates the potential of our automated visual acuity test method to achieve comparable results to the clinical ground truth,established by the expert ophthalmologist’s *** overall accuracy achieved by the proposed model when compared with the expert ophthalmologist test is 91.875%.The proposed method potentially offers a second opinion to ophthalmologists,and serves as a cost-effective pre-screening test to predict eyesight loss at an early stage.

关键词： Eyesight test speech recognition HMM SVM feature extraction

Evaluating the Efficiency of CBAM-Resnet Using Malaysian Sign Language

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2022年第5期71卷 2755-2772页

作者： Rehman Ullah Khan Woei Sheng Wong Insaf Ullah Fahad Algarni muhammad Inam Ul Haq Mohamad Hardyman bin Barawi muhammad asghar Khan Faculty of Cognitive Sciences and Human Development Universiti Malaysia SarawakKuching94300Malaysia Hamdard Institute of Engineering and Technology Islamabad44000Pakistan College of Computing and Information Technology The University of BishaBisha61922Saudi Arabia Department of Computer Sciences Khushal Khan Khattak UniversityKarak27200Pakistan

The deaf-mutes population is constantly feeling helpless when others do not understand them and vice *** fill this gap,this study implements a CNN-based neural network,Convolutional Based Attention Module(CBAM),to recognise Malaysian Sign Language(MSL)in videos *** study has created 2071 videos for 19 dynamic *** different experiments were conducted for dynamic signs,using CBAM-3DResNet implementing‘Within Blocks’and‘Before Classifier’*** metrics such as the accuracy,loss,precision,recall,F1-score,confusion matrix,and training time were recorded to evaluate the models’*** showed that CBAM-ResNet models had good performances in videos recognition tasks,with recognition rates of over 90%with little ***‘Before Classifier’is more efficient than‘Within Blocks’models of *** experiment results indicated the CBAM-ResNet‘Before Classifier’efficiency in recognising Malaysian Sign Language and its worth of future research.

关键词： CBAM-ResNet malaysian sign language within blocks before classifier efficiency evaluation