| 1. |
- Abbas, Muhammad Tahir, et al.
(författare)
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An adaptive approach to vehicle trajectory prediction using multimodel Kalman filter
- 2020
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Ingår i: European transactions on telecommunications. - : Wiley-Blackwell. - 1124-318X .- 2161-3915.
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Tidskriftsartikel (refereegranskat)abstract
- With the aim to improve road safety services in critical situations, vehicle trajectory and future location prediction are important tasks. An infinite set of possible future trajectories can exit depending on the current state of vehicle motion. In this paper, we present a multimodel-based Extended Kalman Filter (EKF), which is able to predict a set of possible scenarios for vehicle future location. Five different EKF models are proposed in which the current state of a vehicle exists, particularly, a vehicle at intersection or on a curve path. EKF with Interacting Multiple Model framework is explored combinedly for mathematical model creation and probability calculation for that model to be selected for prediction. Three different parameters are considered to create a state vector matrix, which includes vehicle position, velocity, and distance of the vehicle from the intersection. Future location of a vehicle is then used by the software-defined networking controller to further enhance the safety and packet delivery services by the process of flow rule installation intelligently to that specific area only. This way of flow rule installation keeps the controller away from irrelevant areas to install rules, hence, reduces the network overhead exponentially. Proposed models are created and tested in MATLAB with real-time global positioning system logs from Jeju, South Korea.
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| 2. |
- Abbas, Muhammad Tahir, et al.
(författare)
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Road-Aware Estimation Model for Path Duration in Internet of Vehicles (IoV)
- 2019
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Ingår i: Wireless personal communications. - : Springer. - 0929-6212 .- 1572-834X. ; 109:2, s. 715-738
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Tidskriftsartikel (refereegranskat)abstract
- In Internet of Vehicles (IoV), numerous routing metrics have been used to assess the performance of routing protocols such as, packet delivery ratio, throughput, end-to-end delay and path duration. Path duration is an influential design parameter, among these routing metrics, that determines the performance of vehicular networks. For instance, in highly dynamic scenarios, it can be used to predict link life time in on-demand routing protocols. In this paper, we propose an infrastructure-assisted hybrid road-aware routing protocol which is capable of enhanced vehicle-to-vehicle and vehicle-to-infrastructure communication. A remarkable aspect of the proposed protocol is that it establishes a link between path duration and fundamental design parameters like vehicular velocity, density, hop count and transmission range. Although, a lot of research has been previously performed, a well defined analytical model for IoV is not available in the literature. Precisely, a relation between path duration and vehicular velocity has not been validated in the previous studies. Experimental results show that the increased packet delivery ratio with reduced end-to-end delay can be achieved by the prediction of path duration. Proposed model for path duration is validated by getting experimental results from network simulator 3 (NS3) and analytical results from MATLAB. In addition, SUMO simulator was used to generate real time traffic on the roads of Gangnam district, South Korea.
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| 3. |
- Abbas, Muhammad Tahir, et al.
(författare)
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SD-IoV : SDN enabled routing for internet of vehicles in road-aware approach
- 2019
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Ingår i: Journal of Ambient Intelligence and Humanized Computing. - : Springer. - 1868-5137 .- 1868-5145. ; 11:3, s. 1265-1280
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Tidskriftsartikel (refereegranskat)abstract
- Proposing an optimal routing protocol for internet of vehicles with reduced overhead has endured to be a challenge owing to the incompetence of the current architecture to manage flexibility and scalability. The proposed architecture, therefore, consolidates an evolving network standard named as software defined networking in internet of vehicles. Which enables it to handle highly dynamic networks in an abstract way by dividing the data plane from the control plane. Firstly, road-aware routing strategy is introduced: a performance-enhanced routing protocol designed specifically for infrastructure-assisted vehicular networks. In which roads are divided into road segments, with road side units for multi-hop communication. A unique property of the proposed protocol is that it explores the cellular network to relay control messages to and from the controller with low latency. The concept of edge controller is introduced as an operational backbone of the vehicle grid in internet of vehicles, to have a real-time vehicle topology. Last but not least, a novel mathematical model is estimated which assists primary controller in a way to find not only a shortest but a durable path. The results illustrate the significant performance of the proposed protocol in terms of availability with limited routing overhead. In addition, we also found that edge controller contributes mainly to minimizes the path failure in the network.
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| 4. |
- Bibi, Uzma, et al.
(författare)
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Graphene-Based Strain Sensing of Cementitious Composites with Natural and Recycled Sands
- 2023
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Ingår i: Sensors. - : MDPI. - 1424-8220. ; 23:16
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Tidskriftsartikel (refereegranskat)abstract
- Structural health monitoring is crucial for ensuring the safety and reliability of civil infrastructures. Traditional monitoring methods involve installing sensors across large regions, which can be costly and ineffective due to the sensors damage and poor compliance with structural members. This study involves systematically varying the graphene nanoplatelets (GNPs) concentration and analyzing the strength performance and piezoresistive behavior of the resulting composites. Two different composites having natural and recycled sands with varying percentages of GNPs as 2%, 4%, 6%, and 8% were prepared. Dispersion of GNPs was performed in superplasticizer and then ultrasonication was employed by using an ultrasonicator. The four-probe method was utilized to establish the piezoresistive behavior. The results revealed that the compressive strength of mortar cubes with natural sand was increased up to a GNP content of 6%, beyond which it started to decline. In contrast, specimens with recycled sand showed a continuous decrease in the compressive strength. Furthermore, the electrical resistance stability was observed at 4% for both natural and recycled sands specimens, exhibiting linearity between the frictional change in the resistivity and compressive strain values. It can be concluded from this study that the use of self-sensing sustainable cementitious composites could pave their way in civil infrastructures.
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| 5. |
- Ghumman, Iss, et al.
(författare)
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Computational Fluid Mechanics Model for Numerical Investigation of Frictional Tribo-pair during Mixed Lubrication
- 2022
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Ingår i: Proceedings of 2022 19th International Bhurban Conference on Applied Sciences and Technology, IBCAST 2022. - : Institute of Electrical and Electronics Engineers Inc.. - 9781665460514 ; , s. 815-820
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Konferensbidrag (refereegranskat)abstract
- All the machines are constructed through mechanical links and pairs. One of the crucial pairs is the sliding pair; due to their nature and general use, they are often subjected to a higher degree of dynamics and external forces leading to high frictional force. To reduce wear from friction formerly thick film of commercial oil is used. However, viscosity-based higher thickness yields higher energy losses, and nano-lubricants are popular in reducing friction while keeping film thickness and improving wear resistance. This paper develops a numerical model for sliding pairs that predicts the load carried by components under different lubrication regimes. The aim is to simulate hydrodynamic and mixed lubrication regimes for different loading conditions. A detailed multiphysics model of tribo-pair was modeled, including lubricant rheology, surface topology, oil film squeeze, and film temperature through the moving mesh. The fluid domain has been meshed with Arbitrary Lagrangian and Eulerian techniques. Energy loss due to viscous friction and boundary friction were determined by solving Naiver- Stokes equations in the moving mesh deformable geometry domain. The numerical model was compared with the available literature, and the results are presented. This numerical simulation remained valid and provides the fundamental understanding of oil film thickness and load-carrying capacity of sliding tribo-pair in the presence of nano-lubricants. The developed model is a useful methodology for studying lubricant oil enriched with nanoparticles.
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| 6. |
- Ahmad, Afaq, et al.
(författare)
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Investigation of Circular Hollow Concrete Columns Reinforced with GFRP Bars and Spirals
- 2023
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Ingår i: Buildings. - : MDPI. - 2075-5309. ; 13:4
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Tidskriftsartikel (refereegranskat)abstract
- Glass fiber-reinforced polymer (GFRP) reinforcements are useful alternatives to traditional steel bars in concrete structures, particularly in vertical structural elements such as columns, as they are less prone to corrosion, and impart increasing strength and endurance of buildings. There is limited research on the finite element analysis (FEA) of the structural behavior of hollow glass fiber-reinforced polymer reinforced concrete (GFRPRC) columns. The hollow portion can be used for the service duct and for reducing the self-weight of the members. Numerical analysis of the compressive response of circular hollow concrete columns reinforced with GFRP bars and spirals is performed in this study. This article aims to investigate the axial behavior of hollow GFRP concrete columns and compare it with that of solid steel reinforced concrete (RC) columns as well as hollow steel RC columns. The Abaqus software is used to construct finite element models. After calibration of modeling using an experimental test result as a control model, a parametric study is conducted. The columns with the same geometry, loading, and boundary conditions are analyzed in the parametric study. It is resulted that the hollow GFRP concrete columns provide a greater confinement effect than the solid steel RC columns. The average variation in the ultimate axial load-carrying capacities of the experimental results, from that of the FEA values, is noted to be only 3.87%, while the average difference in the corresponding deformations is 7.08%. Moreover, the hollow GFRP concrete columns possess greater axial load and deformation capacities compared with the solid steel RC columns.
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| 7. |
- Ali, Iftikhar, et al.
(författare)
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Knowledge, Attitude, Awareness, and Barriers Toward Influenza Vaccination Among Medical Doctors at Tertiary Care Health Settings in Peshawar, Pakistan-A Cross-Sectional Study
- 2018
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Ingår i: Frontiers In Public Health. - : FRONTIERS MEDIA SA. - 2296-2565. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Objective: This study intends to evaluate the knowledge, attitude and awareness of medical doctors toward influenza vaccination and the reasons for not getting vaccinated. Methods: A cross-sectional study was carried out among medical doctors in three major tertiary care health settings in Peshawar, Khyber Pakhtunkhwa (KP), Pakistan. A web-based, pre-tested questionnaire was used for data collection. Results: A total of (n = 300) medical doctors were invited, however only (n = 215) participated in the study with a response rate of 71.7%. Among the participants, 95.3% (n = 205) were males with a mean age of 28.67 +/- 3.89 years. By designation, 121(56.3%) were trainee medical officers and 40 (18.6%) were house officers. The majority 102(47.4%) had a job experience of 1-2 years. Of the total sample, 38 (17.7%) doctors reported having received some kind of vaccination, whereas only 19 (8.84%) were vaccinated against influenza. The results identified that the major barriers toward influenza vaccinations included (1) Unfamiliarity with Influenza vaccination availability (Relative Importance Index RII = 0.830), (2) Unavailability of Influenza vaccines due to lack of proper storage area in the institution (RII = 0.634), (3) Cost of vaccine (RII = 0.608), and (4) insufficient staff to administer vaccine (RII = 0.589). Additionally, 156 (72.6%) of doctors were not aware of the influenza immunization recommendation and guidelines published by the Advisory Committee on Immunization Practices (ACIP) and Centre for Disease Control and Prevention (CDC). Physicians obtained a high score (8.27 +/- 1.61) of knowledge and understanding regarding influenza and its vaccination followed by medical officers (8.06 +/- 1.37). Linear Regression analysis revealed that gender was significantly associated with the knowledge score with males having a higher score (8.0 +/- 1.39) than females (6.80 +/- 1.61 beta = -1.254 and CI [-2.152 to -0.355], p = 0.006). Conclusion: A very low proportion of doctors were vaccinated against influenza, despite the published guidelines and recommendations. Strategies that address multiple aspects like increasing awareness and the importance of the influenza vaccine, the international recommendations and enhancing access and availability of the vaccine are needed to improve its coverage and health outcomes.
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| 8. |
- de Vries, Paul S., et al.
(författare)
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Multiancestry Genome-Wide Association Study of Lipid Levels Incorporating Gene-Alcohol Interactions
- 2019
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Ingår i: American Journal of Epidemiology. - : Oxford University Press. - 0002-9262 .- 1476-6256. ; 188:6, s. 1033-1054
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Tidskriftsartikel (refereegranskat)abstract
- A person's lipid profile is influenced by genetic variants and alcohol consumption, but the contribution of interactions between these exposures has not been studied. We therefore incorporated gene-alcohol interactions into a multiancestry genome-wide association study of levels of high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides. We included 45 studies in stage 1 (genome-wide discovery) and 66 studies in stage 2 (focused follow-up), for a total of 394,584 individuals from 5 ancestry groups. Analyses covered the period July 2014-November 2017. Genetic main effects and interaction effects were jointly assessed by means of a 2-degrees-of-freedom (df) test, and a 1-df test was used to assess the interaction effects alone. Variants at 495 loci were at least suggestively associated (P < 1 x 10(-6)) with lipid levels in stage 1 and were evaluated in stage 2, followed by combined analyses of stage 1 and stage 2. In the combined analysis of stages 1 and 2, a total of 147 independent loci were associated with lipid levels at P < 5 x 10(-8) using 2-df tests, of which 18 were novel. No genome-wide-significant associations were found testing the interaction effect alone. The novel loci included several genes (proprotein convertase subtilisin/kexin type 5 (PCSK5), vascular endothelial growth factor B (VEGFB), and apolipoprotein B mRNA editing enzyme, catalytic polypeptide 1 (APOBEC1) complementation factor (A1CF)) that have a putative role in lipid metabolism on the basis of existing evidence from cellular and experimental models.
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| 9. |
- Feitosa, Mary F., et al.
(författare)
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Novel genetic associations for blood pressure identified via gene-alcohol interaction in up to 570K individuals across multiple ancestries
- 2018
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Ingår i: PLOS ONE. - : Public library science. - 1932-6203. ; 13:6
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Tidskriftsartikel (refereegranskat)abstract
- Heavy alcohol consumption is an established risk factor for hypertension; the mechanism by which alcohol consumption impact blood pressure (BP) regulation remains unknown. We hypothesized that a genome-wide association study accounting for gene-alcohol consumption interaction for BP might identify additional BP loci and contribute to the understanding of alcohol-related BP regulation. We conducted a large two-stage investigation incorporating joint testing of main genetic effects and single nucleotide variant (SNV)-alcohol consumption interactions. In Stage 1, genome-wide discovery meta-analyses in approximate to 131 K individuals across several ancestry groups yielded 3,514 SNVs (245 loci) with suggestive evidence of association (P <1.0 x 10(-5)). In Stage 2, these SNVs were tested for independent external replication in individuals across multiple ancestries. We identified and replicated (at Bonferroni correction threshold) five novel BP loci (380 SNVs in 21 genes) and 49 previously reported BP loci (2,159 SNVs in 109 genes) in European ancestry, and in multi-ancestry meta-analyses (P < 5.0 x 10(-8)). For African ancestry samples, we detected 18 potentially novel BP loci (P< 5.0 x 10(-8)) in Stage 1 that warrant further replication. Additionally, correlated meta-analysis identified eight novel BP loci (11 genes). Several genes in these loci (e.g., PINX1, GATA4, BLK, FTO and GABBR2 have been previously reported to be associated with alcohol consumption. These findings provide insights into the role of alcohol consumption in the genetic architecture of hypertension.
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| 10. |
- Shabbir, Faisal, et al.
(författare)
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Experimental and Numerical Investigation of Construction Defects in Reinforced Concrete Corbels
- 2023
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Ingår i: Buildings. - : MDPI. - 2075-5309. ; 13:9
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Tidskriftsartikel (refereegranskat)abstract
- Reinforced concrete corbels were examined in this study for the cracking behavior and strength evaluation, focusing on defects typically found in these structures. A total of 11 corbel specimens were tested, including healthy specimens (HS), specimens with lower concrete strength (LC), specimens with less reinforcement ratio (LR), and specimens with more concrete cover than specifications (MC). The HS specimens were designed using the ACI conventional method. The specimens were tested under static loading conditions, and the actual strengths along with the crack patterns were determined. In the experimental tests, the shear capacity of the HS specimens was 28.18% and 57.95% higher than the LR and LC specimens, respectively. Similarly, the moment capacity of the HS specimens was 25% and 57.52% greater than the LR and LC specimens, respectively. However, in the case of the built-up sections, the shear capacity of the HS specimens was 9.91% and 37.51% higher than the LR and LC specimens, respectively. Likewise, the moment capacity of the HS specimens was 39.91% and 14.30% higher than the LR and LC specimens, respectively. Moreover, a detailed nonlinear finite element model (FEM) was developed using ABAQUS, and a more user-friendly strut and tie model (STM) was investigated toward its suitability to assess the strengths of the corbels with construction defects. The results from FEM and STM were compared. It was found that the FEM results were in close agreement with their experimental counterparts.
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