2021 International Bhurban Conference on Applied Sciences and Technologies (IBCAST)最新文献

{"title":"Nonlinear Backstepping Based Control of Single-phase Inverter in a Standalone Photovoltaic System","authors":"Adil Latif, L. Khan, Saghir Ahmad","doi":"10.1109/IBCAST51254.2021.9393189","DOIUrl":"https://doi.org/10.1109/IBCAST51254.2021.9393189","url":null,"abstract":"This research article presents a nonlinear robust nonlinear control for a single-phase PV inverter. Based on the Lyapunov stability theory, the proposed backstepping controller ensures the desired sinusoidal voltage at the output of the H-bridge inverter designed for a PV system standalone operation. The output voltage of the inverter is maintained even though significant variations are present at the input. The scheme aims to reduce the computational complexity of the system by tracking the desired voltage. The overall system is simulated in MATLAB/SIMULINK, in the presence of MPPT control law and single-phase H-bridge inverter. Various parameters are observed and compared with conventional PID control to endorse the effective performance of the control scheme.","PeriodicalId":234659,"journal":{"name":"2021 International Bhurban Conference on Applied Sciences and Technologies (IBCAST)","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115700965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of Modified Chebyshev Picard Iteration to the Relative Orbital Dynamics Problem","authors":"A. Imran, Faizan Sikandar Wains, Xuechuan Wang, Yue Xiaokui","doi":"10.1109/IBCAST51254.2021.9393269","DOIUrl":"https://doi.org/10.1109/IBCAST51254.2021.9393269","url":null,"abstract":"In this paper we apply the Modified Chebyshev Picard Iteration Method, which uses Chebyshev Polynomials as basis functions to the Orbital Relative Dynamics Problem. We use the mathematical properties of the Chebyshev polynomials to speed up the integration process by parallel problem solving. In this paper we will only apply this method to the Clohessy-Wiltshire model of satellite relative motion, as their is a analytical solution available so we can easily quantify our results in comparison to the analytical method and other numerical methods like ODE45 and ODE113.","PeriodicalId":234659,"journal":{"name":"2021 International Bhurban Conference on Applied Sciences and Technologies (IBCAST)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123768611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Robust Principal Component Analysis of Vortex-induced Vibrations using Particle Image Velocimetry Measurements","authors":"Ahmad Saeed, Z. Bangash, Hamayun Farooq, I. Akhtar","doi":"10.1109/IBCAST51254.2021.9393277","DOIUrl":"https://doi.org/10.1109/IBCAST51254.2021.9393277","url":null,"abstract":"Experimental techniques to measure fluid flow fields often contain measurement noise and corruption leading to missing velocity vectors that degrade data-driven analysis like POD, DMD etc. that are mostly based on least-squares. Here we use a statistical technique, robust principal component analysis (RPCA) to cope with this problem, RPCA removes the corrupted and misleading flow fields and fill in the missing velocity field vectors to improve the quality of the data by using the information of global coherent structures present in data before applying modal decomposition techniques like POD and DMD. RPCA takes the data matrix and decomposes this matrix into two parts first is a low-rank L matrix which contain coherent structures of flow field data and second is a S matrix which is sparse and contains corrupt entries of flow field. RPCA is applied on the numerical data (DNS) and experimental data of circular cylinder. First, we apply RPCA on the data obtained through direct numerical simulation of flow at Reynolds number 100 and add salt and pepper noise artificially to check the performance of RPCA and error analysis. Next, we investigate its performance on the experimental velocity fields data of vortex induced vibrations. Finally, we apply POD and DMD on the RPCA filtered data which are sensitive to noise and outliers. In all cases RPCA correctly identifies the coherent structures and fill in incorrect or missing information through L1 norm.","PeriodicalId":234659,"journal":{"name":"2021 International Bhurban Conference on Applied Sciences and Technologies (IBCAST)","volume":"172 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115024847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identification of Geometrical Parameters Dependency on Aerodynamic and Stability Characteristics of Flying Wing Micro Air Vehicle","authors":"T. Shams, Syed Irtiza Ali Shah, Hassan Abbas, Sara Khushbash, M. Ahmad, K. Mehmood","doi":"10.1109/IBCAST51254.2021.9393015","DOIUrl":"https://doi.org/10.1109/IBCAST51254.2021.9393015","url":null,"abstract":"Flying Wing Micro Air Vehicles (FWMAV) are characterized as small flying machines which have low aspect ratio wings and low mass moment of inertia. These two geometric characteristics make them aerodynamically inefficient and dynamically unstable platform. Further less weight makes these types of vehicles prone to unsteady oscillations during flight, triggered by slight atmospheric gust or minor pilot input. Since they operate at low Reynolds number regime, therefore, laminar separation bubble formation and abrupt bursting of LSB deteriorates their flight performance while low moments of inertia make them unstable in flight and pose difficulty in maintaining steady straight and level trajectory. Despite of many miniaturization problems, these vehicles are found useful in many military and civilian applications like surveillance, reconnaissance, target acquisition and ground mapping, just to name a few. These missions demand high endurance along with stable flight with no disturbances or unwanted oscillations. This research has identified a knowledge gap in literature concerning geometrical variables dependency on aerodynamic and stability characteristics of flying wing micro aerial vehicle (FWMAV). Geometric variables considered for many surrogate models were aspect ratio, dihedral angle and leading edge sweep. Since aerodynamic performance of vehicle is contingent on airfoil efficiency, therefore this research has focused on the selection criteria of optimal airfoil for better endurance characteristics. Potential flow solver has been used for analysis purposes of 2D airfoils and 3D wings. Validation of computational results was carried out with wind tunnel tests by comparing static stability coefficients. It was found that lateral dynamics posed a larger problem as compared to longitudinal. Though pitch stability was difficult to achieve, still, Dutch-Roll and Spiral modes were found as main problematic areas to achieve steady flight. The research concluded that for low mass moment of inertia vehicles, lateral and directional stability does not only depend upon sweep and dihedral angle but aspect ratio also played a significant role. A dependency of longitudinal, lateral and directional stability parameters as function of geometrical parameters (aspect ratio, wing leading edge sweep and dihedral angle) is proposed.","PeriodicalId":234659,"journal":{"name":"2021 International Bhurban Conference on Applied Sciences and Technologies (IBCAST)","volume":"113 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116036152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Novel Miniaturized Frequency Selective Surface for EMI Shielding Applications","authors":"M. Idrees, Siama Buzdar, Siafullah Khalid, M. A. Khalid","doi":"10.1109/IBCAST51254.2021.9393313","DOIUrl":"https://doi.org/10.1109/IBCAST51254.2021.9393313","url":null,"abstract":"In this paper, a thin single layer miniaturized band-reject frequency selective surface (FSS) is presented for electromagnetic interference (EMI) shielding applications. This FSS consists of a convoluted circular loop (CCL) and achieves an effective shielding in the X-band. The FSS unit cell is designed over a thin Rogers 5880 laminate. Moreover, this CCL FSS offers 3-dB fractional bandwidth of 21 % and exhibits stable frequency response over oblique incidence angles for both the TE and TM modes of polarization. Thus, the proposed FSS is a suitable candidate for narrowband selective shielding applications.","PeriodicalId":234659,"journal":{"name":"2021 International Bhurban Conference on Applied Sciences and Technologies (IBCAST)","volume":"93 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114565605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A New Model for Co-Ratings Based Similarity in Collaborative Filtering","authors":"Mubbashir Ayub, Tasawer Khan, Muhammad Shafqat","doi":"10.1109/IBCAST51254.2021.9393308","DOIUrl":"https://doi.org/10.1109/IBCAST51254.2021.9393308","url":null,"abstract":"Collaborative Filtering recommender systems use the history of user ratings to construct a usually very sparse user-item rating matrix and then use some similarity measurement algorithm to find similar user/items for prediction purpose. Conventional similarity measures such as PCC or Cosine works only on co-rated items and ignore the rating of items that are not rated commonly. Besides, the accuracy of these measures is not very high. Advanced similarity measures such as NHSM and Bhattacharya Co-efficient give comparable accuracy but ignores the weightage of the number of co-rated items. In this paper, we aim to use not only the rating values of co-rated items but also consider the weightage of the number of co-rated items. Moreover, in our improved similarity measure, named Improved_CF we take into account the ratings of non-co-rated items also. Experiments on four publically available datasets (i.e. CiaoDVD, Filmtrust, MovieLens-100K, Epinions) are used to establish the effectiveness of our proposed model. Both prediction and classification accuracy metrics are used as evaluation parameters.","PeriodicalId":234659,"journal":{"name":"2021 International Bhurban Conference on Applied Sciences and Technologies (IBCAST)","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127038306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploiting Spatiotemporal Features for Action Recognition","authors":"Usairam Bin Muslim, M. H. Khan, M. S. Farid","doi":"10.1109/IBCAST51254.2021.9393316","DOIUrl":"https://doi.org/10.1109/IBCAST51254.2021.9393316","url":null,"abstract":"Action recognition from videos is important due to its numerous applications in real life scenarios. Most commonly action recognition is used for surveillance but it is also used in other applications such as entertainment and gaming. Moreover, due to high demand of automation and easy availability of higher processing power, researchers are aiming for better ways to accurately classify human actions using videos. Different methods have been proposed in literature in order to identify actions. However, most of these methods suffer from limitations such as implementation complexity and inability to recognize complex actions. In this paper, we propose a novel action recognition technique which is easy to implement and is robust to complex actions. While there are different methods to capture motion, trajectories based methods have proven to be an excellent way to represent motion in videos. Inspired by that, we sampled dense points in different frames of the video to track down their displacement information to encode the trajectories. We used dense trajectories along with oriented gradients and motion boundary information as features. We use codebook generated using Gaussian mixture model and Fisher vector to encode our features. Finally, after reducing the dimensionality of our data, we use linear Support Vector Machine to identify the actions. The experimental evaluations performed on a recent benchmark action recognition dataset showed that our method is able to achieve encouraging results compared to other competing methods.","PeriodicalId":234659,"journal":{"name":"2021 International Bhurban Conference on Applied Sciences and Technologies (IBCAST)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130624114","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel Sensor Fault Detection and Isolation for an Unmanned Aerial Vehicle","authors":"Hamid Maqsood, M. Taimoor, Z. Ullah, N. Ali, Muhammad Sohail","doi":"10.1109/IBCAST51254.2021.9393247","DOIUrl":"https://doi.org/10.1109/IBCAST51254.2021.9393247","url":null,"abstract":"To avoid adverse impacts on humans and the environment and upon the system itself, early detection and isolation of faults and failures in the flight control system are crucial. This paper focuses on designing a novel detection and isolation (FDI) of sensor faults in quadrotors. The traditional nonlinear fault detection techniques including integral chain differentiator and high gain observer are incorporated to realize the accurate reconstruction of the sensor faults. However, the proposed approach based on the improved high gain observer is employed that offers fast detection of sensor faults with improved detection accuracy and lower gain requirement than the traditional observer. Various simulation results validate the superiority of the proposed FDI method and prove its efficacy under the influence of different fault scenarios.","PeriodicalId":234659,"journal":{"name":"2021 International Bhurban Conference on Applied Sciences and Technologies (IBCAST)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130665036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A New Approach for Dehazing and Enhancement of Infrared Images","authors":"M. Nawaz, G. Raja, M. Qasim","doi":"10.1109/IBCAST51254.2021.9393238","DOIUrl":"https://doi.org/10.1109/IBCAST51254.2021.9393238","url":null,"abstract":"This paper proposes the implementation of an algorithm that dehazes and enhances outdoor infrared (IR) images. Dehazing is carried out through dark channel prior (DCP) and enhancement is achieved by multi-scale retinex (MSR) technique. The atmospheric light present in the haze concentrated image is approximated and a transmission map is estimated which separates out the concentration of haze. Enhancement of dehazed images is done by augmenting the image contrast directly instead of unraveling the physical model of image degradation. The reflectance component of image is acquired by approximating the atmospheric brightness of scene. Resulting images are then assimilated in optical attenuation model to recover the final output image. The proposed method is implemented using MATLAB and is validated by assessing the images according to their average gradient, information entropy, and root mean square error. Experimental results show that the proposed method can remove the haze concentration in images successfully and enhance them significantly.","PeriodicalId":234659,"journal":{"name":"2021 International Bhurban Conference on Applied Sciences and Technologies (IBCAST)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123942650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Underwater Navigation, Localization and Path Planning for Autonomous Vehicles: A Review","authors":"Fahad Jalal, Faizan Nasir","doi":"10.1109/IBCAST51254.2021.9393315","DOIUrl":"https://doi.org/10.1109/IBCAST51254.2021.9393315","url":null,"abstract":"Recently, there has been increasing interest in the field of Autonomous Underwater Vehicle (AUV) navigation and localization. Navigation is a critical element for AUV because of the absence of reliable positioning system and complexity of unstable environment. Precise navigation and localization is required for AUVs for positioning, tracking, control and guidance, due to impossible relying on radio communication and global positioning systems, navigation, communication and localization in underwater environment are considered as challenge. Path Planning is important and necessary for various application including AUVs, major task is to plan and manage safe and secure routes with minimum energy and cost. Acoustic system was considered as main approach but there were still some shortcomings. Researcher have explored different alternatives. A review of recent advances and future challenges are identifies to analyze and summarize these alternatives, Path planning for the multiple AUVs is discussed in detail for the both predictable and unpredictable environments also a various underwater navigation and localization algorithms are discussed.","PeriodicalId":234659,"journal":{"name":"2021 International Bhurban Conference on Applied Sciences and Technologies (IBCAST)","volume":"105 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124302867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}