A Simple and Cost-effective Design for Simultaneous Transmission of Point-to-point and Broadcast Services in WDM-PON

Ahmed Muddassir Khan,Zhang Jie,Yousaf Khan,Muhammad Idrees,Yongli Zhao,Shahab Niazi,Aftab Husein,Abid Munir,Ishtiaq Ahmed,Junyan Liu 보안공학연구지원센터 2013 International Journal of Future Generation Communi Vol.6 No.3

Neural network based direct torque control for doubly fed induction generator fed wind energy systems

Aftab Ahmed Ansari,Giribabu Dyanamina Techno-Press 2023 Advances in computational design Vol.8 No.3

Torque ripple content and variable switching frequency operation of conventional direct torque control (DTC) are reduced by the integration of space vector modulation (SVM) into DTC. Integration of space vector modulation to conventional direct torque control known as SVM-DTC. It had been more frequently used method in renewable energy and machine drive systems. In this paper, SVM-DTC is used to control the rotor side converter (RSC) of a wind driven doubly-fed induction generator (DFIG) because of its advantages such as reduction of torque ripples and constant switching frequency operation. However, flux and torque ripples are still dominant due to distorted current waveforms at different operations of the wind turbine. Therefore, to smoothen the torque profile a Neural Network Controller (NNC) based SVM-DTC has been proposed by replacing the PI controller in the speed control loop of the wind turbine controller. Also, stability analysis and simulation study of DFIG using process reaction curve method (RRCM) are presented. Validation of simulation study in MATLAB/SIMULINK environment of proposed wind driven DFIG system has been performed by laboratory developed prototype model. The proposed NNC based SVM-DTC yields superior torque response and ripple reduction compared to other methods.

A study on finite element of pre damaged stress concentration factor for a composite laminate member with central circular

T. Ahmed,R. S. Choudhry,Atta Ur Rehman Shah,Hasan Aftab Saeed 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.8

The study investigates the pre damaged stress concentration factor (SCF) for a composite laminate member (CLM) with central circular hole subjected to tensile loading. The presence of holes yields high stress concentrations in the structural members termed as stress raiser and often regarded as an important design deriver. The pre damaged SCF refers to the stress concentrations within elastic (undamaged) range of the CLM prior to the failure initiation. The traditional experimental and analytical methods for the estimation of SCF offer macro level behaviour which is not considered appropriate for CLM where lamina by lamina behaviour is more significant. A meso level finite element (FE) model is presented to capture the lamina by lamina influence on the overall SCF for a CLM using commercial software Abaqus. The paper deals with the fundamental influencing factors such as laminae orientation effect, stress distribution effect around periphery of the hole, decaying effect and ligament effect on SCF for CLM. Analytical models have been formulated to validate the FE models. The results of FE models have been found in close agreement with the analytical results.

Integration of RFID Network Planning with Xbee Network : A New Approach

Khalid Hasnan,Aftab Ahmed,Badrul-aisham,Qadir Bakhsh,Kamran Latif,Kashif Hussain 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.4

Radio Frequency Identification (RFID) is a wireless technology used for real time identification and data capture of items. It replaces the traditional barcode at retail shop, warehousing, logistics and supply chain management etc. The basic requirements for deploying RFID network are to know the number of readers needed, location of the readers and the efficient power setting for each reader. The optimal solution of RFID network planning problems can be achieved by the implementation of newly developed Multi-Colony Global Particle Swarm Optimization (MC-GPSO) algorithm, which computes objective functions scientifically. However owing to the limited transmission range of RFID reader, it can track and identify items within specified range only. A novel approach to integrate RFID network planning with XBee wireless mesh network was developed. It could enhance the communication range and visibility of items identification and tracking activity faster and accurate. It also increases the tracking activity of multiple items as compared to existing barcode technology. RFID system is able to reduce the product loss or shrinkage and bullwhip effect resulting to reduce the overall cost. It also reduces the time of data transfer in global network.

Distance Learning in an Enterprise Manufacturing Network

Kenneth Ebeling,Syed Aftab Ahmed,Sung - Youl Lee 대한산업공학회 2003 대한산업공학회 추계학술대회논문집 Vol.2003 No.-

Sentiment Analysis for COVID-19 Vaccine Popularity

( Muhammad Saeed ),( Naeem Ahmed ),( Abid Mehmood ),( Muhammad Aftab ),( Rashid Amin ),( Shahid Kamal ) 한국인터넷정보학회 2023 KSII Transactions on Internet and Information Syst Vol.17 No.5

Social media is used for various purposes including entertainment, communication, information search, and voicing their thoughts and concerns about a service, product, or issue. The social media data can be used for information mining and getting insights from it. The World Health Organization has listed COVID-19 as a global epidemic since 2020. People from every aspect of life as well as the entire health system have been severely impacted by this pandemic. Even now, after almost three years of the pandemic declaration, the fear caused by the COVID-19 virus leading to higher depression, stress, and anxiety levels has not been fully overcome. This has also triggered numerous kinds of discussions covering various aspects of the pandemic on the social media platforms. Among these aspects is the part focused on vaccines developed by different countries, their features and the advantages and disadvantages associated with each vaccine. Social media users often share their thoughts about vaccinations and vaccines. This data can be used to determine the popularity levels of vaccines, which can provide the producers with some insight for future decision making about their product. In this article, we used Twitter data for the vaccine popularity detection. We gathered data by scraping tweets about various vaccines from different countries. After that, various machine learning and deep learning models, i.e., naive bayes, decision tree, support vector machines, k-nearest neighbor, and deep neural network are used for sentiment analysis to determine the popularity of each vaccine. The results of experiments show that the proposed deep neural network model outperforms the other models by achieving 97.87% accuracy.

ROBUST DIFFERENTIAL STEERING CONTROL SYSTEM FOR AN INDEPENDENT FOUR WHEEL DRIVE ELECTRIC VEHICLE

Muhammad Arshad Khan,Muhammad Faisal Aftab,Ejaz Ahmed,윤일중 한국자동차공학회 2019 International journal of automotive technology Vol.20 No.1

This research investigates a robust differential steering control system (DSCS) for an independent four wheel drive electric vehicle (EV). The DSCS will maneuver the independently actuated (IA) four wheel drive EV without the help of any conventional steering mechanism (CSM) via the input torque of the four wheels. The differential angular rotation speed between left and right wheels is used to generate the CSM effects. The DSCS is designed using the linear model of the vehicle with linear tire dynamics and is tested in simulations using a nonlinear vehicle model with nonlinear tire dynamics. The proposed DSCS is a combination of forward speed and yaw rate controllers, designed using the robust H∞ control methodology. The effectiveness of the proposed robust controller is analyzed by comparing the performance of the all-wheel drive (AWD), the rear wheel drive (RWD), and the front wheel drive (FWD) vehicles during simulations. The simulations results indicates that the proposed system can successfully maneuver the vehicle under different driving conditions by tracking the desired parameters without the use of any CSM.

Locator Placement Optimization for Minimum Part Positioning Error During Machining Operation Using Genetic Algorithm

Sajid Ullah Butt,Mamoona Arshad,Aamer Ahmed Baqai,Hasan Aftab Saeed,Naveed Akmal Din,Rehan Ahmed Khan 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.22 No.5

Fixture design is one of the main factors which affect the final product quality. Proper design of fixture plays an important role in ensuring the required tolerance of the product. Proper placement of locators is one of the prominent factors in fixture design. Locators are elastic: they deform under clamping and machining forces causing rigid body displacement of the workpiece which in turn affects the part quality. In this article, a 3-2-1 type of fixturing system having elastic locators around a considerably rigid rectangular workpiece is considered. A genetic algorithm is proposed, which uses a fitness function that evaluates the positioning error of the workpiece under external forces and torque. Among several variables, 12 variables, which define the placement of locators, are chosen to be optimized while minimizing the positioning error of the workpiece at the point of action of machining force. The proposed algorithm optimizes the 12 interlinked variables, within the specified region, for machining force and torque at a single point. However, when the cutting tool moves to any other point on the workpiece, it is observed that either the workpiece loses its contact with any one of the locators or the positioning error increases by a large value. To overcome this issue, the proposed algorithm is further modified for placement optimization to cater for multi-point machining, and the isostatism of the workpiece is ensured by checking the magnitude and direction of displacement (of what?) at each point of workpiece-locator contact. Finally, the original and modified GA algorithms are explained through a case study where the single point optimized placement shows loss of contact when machining force is applied at other points. The placement optimized from the modified algorithm shows that the isostatism of the workpiece remains intact while all four positioning errors are converged towards the same value. The results obtained from the proposed and modified algorithm are verified using ANSYS simulation.

Description of novel variants in consanguineous Pakistani families affected with intellectual disability

Rasool Iqra Ghulam,Zahoor Muhammad Yasir,Ahmed Irfan,Iqbal Muhammad,Shafqat Shehla,Anjum Aftab Ahmad,Shehzad Wasim 한국유전학회 2023 Genes & Genomics Vol.45 No.4

Background Intellectual disability (ID) is a neurodevelopmental condition, affecting 1–3% of the population. Genetic factors play a key role causing the limitation in intellectual functioning and adaptive behavior. The heterogeneity of ID makes it more difficult for genetic and clinical diagnosis. Mapping of variants through next generation DNA sequencing in consanguineous families would help to understand the molecular parthenogenesis of ID. Objective The aim of this study was to describe the genetic variants of ID in consanguineous Pakistani families. Methods We analyzed four unrelated consanguineous Pakistani families having an intellectual disability through whole exome sequencing (WES). Data was analyzed using different bioinformatics tools and software. Results We mapped four novel variants in different ID genes. Each variant is found in different family, co-segregating with a recessive pattern of inheritance. The variants found are; c.1437delG:p.Asn480Thrfs*10, mapped in FKRP, c.2041 C>A:p.Leu681Met in HIRA, c.382 C>T:p.Arg128Cys in BDH1 and c.267+1G>A:p.? identified in TRAPPC6B. Conclusions These variants help in demonstration of status and molecular basis of intellectual disability in Pakistani population leading to provision of genetic counseling services and a contribution in disease variant database.

Some Pyridyl- and Thiophenyl- Substituted 1,2,4-Triazolo[3,4-b]1,3,4-thiadiazole Derivatives as Potent Antibacterial

Muhammad Rizwan Maqsood,Muhammad Hanif,Muhammad Rafiq,Muhammad Saleem,Sumera Zaib,Aftab Ahmed Khan,Mazhar Iqbal,Jamshed Iqbal,Nasim Hasan Rama,서승염,Ki-Hwan Lee 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.12

The target compounds 6-11a-e were synthesized by condensing 4-amino-5-aryl-3H-1,2,4-triazole-3-thiones 5a-f with various aromatic carboxylic acids in the presence of phosphorous oxychloride. The structures of newly synthesized compounds were characterized by IR, 1H NMR, 13C NMR, elemental analysis and mass spectrometric studies. All the synthesized compounds were screened for their antibacterial activity. Almost all the tested compounds were potent against four different strains of bacteria when compared with that of reference drug ciprofloxacin. Compounds 6c, 6e, 8d, 9b, 9e, 11a and 11b showed nearly equal or lower MIC values than standard drug, against all four tested bacterial strains but rest of the compounds showed excellent antibacterial activities.