Dr Ahsan Ali - Academia.edu (original) (raw)

Papers by Dr Ahsan Ali

Proceedings of the 9th International Conference on Machine Learning and Computing

While a hard clustering algorithm lets a pattern to belong to a single cluster class, soft cluste... more While a hard clustering algorithm lets a pattern to belong to a single cluster class, soft clustering allows patterns to belong to all cluster classes with different degrees of relationship. This is important in the case of short-text clustering, in which a small-sized text fragment such as a quotation or sentence may be related to more than one subject or topic. However, soft clustering of short-text is complicated by the computational difficulties inherent in defining cluster centroids using conventional cluster centrality measures. Therefore, this paper proposes a new soft short-text clustering algorithm based on the use of PageRank as a centrality measure. Results suggest that when used in hard clustering mode, its performance is on par with state-of-the-art spectral clustering algorithms. Advantages of the algorithm include its ability to perform soft clustering, its ability to operate on non-symmetric matrices, and its ability to converge automatically to an appropriate number of cluster classes.

Mathematics

Medical image acquisition devices are susceptible to producing blurry images due to respiratory a... more Medical image acquisition devices are susceptible to producing blurry images due to respiratory and patient movement. Despite having a notable impact on such blind-motion deblurring, medical image deblurring is still underexposed. This study proposes an end-to-end scale-recurrent deep network to learn the deblurring from multi-modal medical images. The proposed network comprises a novel residual dense block with spatial-asymmetric attention to recover salient information while learning medical image deblurring. The performance of the proposed methods has been densely evaluated and compared with the existing deblurring methods. The experimental results demonstrate that the proposed method can remove blur from medical images without illustrating visually disturbing artifacts. Furthermore, it outperforms the deep deblurring methods in qualitative and quantitative evaluation by a noticeable margin. The applicability of the proposed method has also been verified by incorporating it into ...

Journal of Functional Biomaterials

Zn-based biodegradable alloys or composites have the potential to be developed to next-generation... more Zn-based biodegradable alloys or composites have the potential to be developed to next-generation orthopedic implants as alternatives to conventional implants to avoid revision surgeries and to reduce biocompatibility issues. This review summarizes the current research status on Zn-based biodegradable materials. The biological function of Zn, design criteria for orthopedic implants, and corrosion behavior of biodegradable materials are briefly discussed. The performance of many novel zinc-based biodegradable materials is evaluated in terms of biodegradation, biocompatibility, and mechanical properties. Zn-based materials perform a significant role in bone metabolism and the growth of new cells and show medium degradation without the release of excessive hydrogen. The addition of alloying elements such as Mg, Zr, Mn, Ca, and Li into pure Zn enhances the mechanical properties of Zn alloys. Grain refinement by the application of post-processing techniques is effective for the developme...

Energies

Solar energy is the most promising green energy resource, as there is an enormous supply of solar... more Solar energy is the most promising green energy resource, as there is an enormous supply of solar power. It is considered a good potential solution for energy crises in both domestic and industrial sectors. Nowadays, many types of solar systems are used for harvesting solar energy. Most of the research is focused on direct absorption solar collectors (DASCs) due to their ability to capture more solar energy. The effectiveness of DASCs is dependent on various factors, such as working fluid properties, geometry, and operating parameters. This review summarizes the impact of different design and operating parameters on the performance of DASCs. Many effective parameters are considered and their impact on optical and thermal properties is summarized. The influence of working fluid parameters, such as base fluid type, nanoparticle type, nanoparticle size, nanoparticle shape, and nanoparticle concentration on heat transfer performance, was discussed and their optimum range was suggested. ...

Journal of Indian Business Research

Purpose The purpose of this study is to empirically test the impact of resilience-enhancing human... more Purpose The purpose of this study is to empirically test the impact of resilience-enhancing human resource practices on job satisfaction and organizational commitment with the mediating role of employee resilience. Design/methodology/approach With a quantitative approach, structural equation modeling was used to test the hypothesis. Data was collected with a survey method from 326 bankers of Pakistan. Data was diagnosed with all reliability and validity tests and significance was tested with bootstrapping. Smart-PLS software was used. Findings Results revealed that there is a partial mediating impact of employee resilience in the relationship of resilience-enhancing human resource practice and job satisfaction. For resilience-enhancing human resource practice and organizational commitment, employee resilience plays a partial mediating role. Research limitations/implications This study is confined to bankers only and a limited sample is used. However, it significantly provides a cont...

2017 IEEE 85th Vehicular Technology Conference (VTC Spring)

Spatial models for the locations of base stations (BSs) in cellular networks have long been desir... more Spatial models for the locations of base stations (BSs) in cellular networks have long been desirable since they play a pivotal role in evaluating the mutual interference and, hence, overall performance of the network. The Poisson point process (PPP) is the most analytically tractable and widely used model for the location of BSs, but it fails to capture the underlying separation between the BSs of cellular networks. In this paper we use the most recent proposed model, the β-Ginibre point process (β-GPP), for the locations of BSs to capture the underlying separation between them. Simple yet accurate approximations for the Laplace transform of interference are still missing from the research literature for a β-GPP model. We address this shortcoming, and provide an approximate expression for the Laplace transform of interference using the diagonal approximation for computing the determinant of the kernel matrix K of a β-GPP. We apply that expression to derive a simple computable integral representation for the coverage probability of a typical user under the assumption of a Rayleigh fading channel. To show the accuracy of our derived expression, we compare it with that obtained by simulations and existing results in literature for different values of β. Further, we show that for the value of β=0, our derived expression become equal to the PPP case. Here, we also provide the extensive simulation results to validate the accuracy of our derived analytical expressions.

Polymers

Many researchers and scientists have contributed significantly to provide structural and molecula... more Many researchers and scientists have contributed significantly to provide structural and molecular characterizations of biochemical interactions using microscopic techniques in the recent decade, as these biochemical interactions play a crucial role in the production of diverse biomaterials and the organization of biological systems. The properties, activities, and functionalities of the biomaterials and biological systems need to be identified and modified for different purposes in both the material and life sciences. The present study aimed to review the advantages and disadvantages of three main branches of microscopy techniques (optical microscopy, electron microscopy, and scanning probe microscopy) developed for the characterization of these interactions. First, we explain the basic concepts of microscopy and then the breadth of their applicability to different fields of research. This work could be useful for future research works on biochemical self-assembly, biochemical aggr...

International Journal of Molecular Sciences

Tissue-nonspecific alkaline phosphatase (TNAP) is an ectoenzyme bound to the plasma membranes of ... more Tissue-nonspecific alkaline phosphatase (TNAP) is an ectoenzyme bound to the plasma membranes of numerous cells via a glycosylphosphatidylinositol (GPI) moiety. TNAP’s function is well-recognized from earlier studies establishing its important role in bone mineralization. TNAP is also highly expressed in cerebral microvessels; however, its function in brain cerebral microvessels is poorly understood. In recent years, few studies have begun to delineate a role for TNAP in brain microvascular endothelial cells (BMECs)—a key component of cerebral microvessels. This review summarizes important information on the role of BMEC TNAP, and its implication in health and disease. Furthermore, we discuss current models and tools that may assist researchers in elucidating the function of TNAP in BMECs.

Filomat

The purpose of this paper is to introduce the notion of multivalued Hardy-Rogers ??-contraction i... more The purpose of this paper is to introduce the notion of multivalued Hardy-Rogers ??-contraction in the sense of generalized simulation functions and to present the corresponding fixed point results with some examples. Moreover, we study the strict fixed point and well-posedness, data dependence, as well as, the Ulam-Hyres stability of the fixed point problem. As an application, we prove the existence of the solution for nonlinear fractional differential equation involving Caputo fractional derivative.

MARKHOR (The Journal of Zoology)

GeneXpert is attributed as one of the latest technical means for diagnosing Tuberculosis in very ... more GeneXpert is attributed as one of the latest technical means for diagnosing Tuberculosis in very short period of time. Objectives: To evaluate the efficiency of GeneXpert and fluorescent microscopy in the detection of pulmonary tuberculosis (TB); To compare the sensitivity and specificity of GeneXpert and fluorescent microscope in the diagnosis of Mycobacterium tuberculosis Methods: In the present investigation, the diagnostic performance of GeneXpert MTB / RIF for tuberculosis was compared with the performance of light-emitting diode fluorescence microscope in TB samples from Narowal, Pakistan. For this purpose, a total of 299 TB positive specimens were obtained. Among these 54% (n = 160) were categorized to be obtained from male and 46% (n = 139) from female population. Data collected was distributed in 4 age groups; 0-20, 21-40, 41-60, and 61-80, in which the percentage and number of samples were found as 2% (n = 6), 60% (n = 179), 27% (n = 80) and 11% (n = 34), respectively. Res...

Proceedings of the ... AAAI Conference on Artificial Intelligence, May 18, 2021

Data heterogeneity has been identified as one of the key features in federated learning but often... more Data heterogeneity has been identified as one of the key features in federated learning but often overlooked in the lens of robustness to adversarial attacks. This paper focuses on characterizing and understanding its impact on backdooring attacks in federated learning through comprehensive experiments using synthetic and the LEAF benchmarks. The initial impression driven by our experimental results suggests that data heterogeneity is the dominant factor in the effectiveness of attacks and it may be a redemption for defending against backdooring as it makes the attack less efficient, more challenging to design effective attack strategies, and the attack result also becomes less predictable. However, with further investigations, we found data heterogeneity is more of a curse than a redemption as the attack effectiveness can be significantly boosted by simply adjusting the client-side backdooring timing. More importantly, data heterogeneity may result in overfitting at the local training of benign clients, which can be utilized by attackers to disguise themselves and fool skewed-feature based defenses. In addition, effective attack strategies can be made by adjusting attack data distribution. Finally, we discuss the potential directions of defending the curses brought by data heterogeneity. The results and lessons learned from our extensive experiments and analysis offer new insights for designing robust federated learning methods and systems.

WSEAS Transactions on Computers archive, Jun 1, 2008

Employee motivation is one of the key drivers of success in today's competitive environment. Rele... more Employee motivation is one of the key drivers of success in today's competitive environment. Relevant literature generally explains that motivated employees can perform their tasks much better than demotivated workers. It is due to this reason that there is always a requirement of a comprehensive framework that should be able to provide complete guidelines with the help of which supervisors * should be able to identify core factors that motivate employees. Keeping in line the requirement stated earlier, this research paper presents a self formulated † framework i.e. 'Imperative Motivational Factors Framework' (IMFF). This proposed framework familiarizes necessary stakeholders with the core motivational factors' identification process. The framework takes into account very generic factors identified from various motivational theories, society and industry. Once the generic factors are identified then the framework formulates specific factors for a group of employees and / or for individual employee ‡ .

Chemosensors, 2022

Printing technology promises a viable solution for the low-cost, rapid, flexible, and mass fabric... more Printing technology promises a viable solution for the low-cost, rapid, flexible, and mass fabrication of biosensors. Among the vast number of printing techniques, screen printing and inkjet printing have been widely adopted for the fabrication of biosensors. Screen printing provides ease of operation and rapid processing; however, it is bound by the effects of viscous inks, high material waste, and the requirement for masks, to name a few. Inkjet printing, on the other hand, is well suited for mass fabrication that takes advantage of computer-aided design software for pattern modifications. Furthermore, being drop-on-demand, it prevents precious material waste and offers high-resolution patterning. To exploit the features of inkjet printing technology, scientists have been keen to use it for the development of biosensors since 1988. A vast number of fully and partially inkjet-printed biosensors have been developed ever since. This study presents a short introduction on the printing...

Polymers, 2021

In this research article, an organic polymer based polypyrrole (Ppy) composite material has been ... more In this research article, an organic polymer based polypyrrole (Ppy) composite material has been synthesized and analyzed for the design and fabrication purposes of a fast-responsive, highly sensitive, and an economical resistive-type novel humidity detection sensor. This humidity sensor most suitably serves the purpose for industrial humidity (i.e., values ranging from low to high) detection applications. First, a polypyrrole composite material (a mixture of polypyrrole, polypyrrole-NiO, polypyrrole-CeO2, and polypyrrole-Nb2O5) has been synthesized by chemical oxidative polymerization method, and then is treated at various temperatures, i.e., 100, 150 and 200 °C, respectively. After this treatment, the synthesized samples were then characterized by using FTIR, SEM, and DTA/TGA techniques for analyzing humidity sensing properties. The polypyrrole samples with the best morphological structure and properties were then incorporated on interdigitated electrodes. For the fabrication purp...

Stroke: Vascular and Interventional Neurology, 2021

Introduction : Background: Several accrediting bodies certify the level of stroke care hospitals ... more Introduction : Background: Several accrediting bodies certify the level of stroke care hospitals provide. The Joint Commission on Hospital Accreditation (JC) is the largest accrediting body in the United States. There is no open source Geographic Information Systems (GIS) dataset showing the distribution of JC accredited centers by ZIP code. Objective: to create a stroke center accessibility and stroke center desert system using geospatial analysis and machine learning which provides real‐time assessment of stroke center availability, distribution and access to care. Methods : Geospatial data layers of JC accredited stroke centers were compiled using data sources including U.S. Census Bureau and CDC. Map layers corresponding to the levels of JC accredited stroke hospitals geolocated using ZIP code were created as follows: 1) Acute Stroke Ready 2) Primary 3) Thrombectomy Capable 4) Comprehensive Stroke Center. A GIS dataset displaying stroke mortality by region was obtained from the ...

Asia Pacific Journal of Management, 2021

Research has mostly focused on how formal leadership can shape a climate for innovation, but we k... more Research has mostly focused on how formal leadership can shape a climate for innovation, but we know little about how informal leadership, such as shared leadership, may affect this process. Departing from this dominant focus, we examine how shared leadership may have a positive influence on team processes and performance. Based on social information processing theory, we develop a moderated mediation model that examines the indirect effect of shared leadership on team creativity via a climate for innovation and further investigates the moderating effect of task uncertainty. Two survey-based field studies using multisource, multiwave data support the hypothesized model. The findings reveal that (1) shared leadership positively predicts a climate for innovation, (2) this relationship is stronger when the team faces task uncertainty, (3) a climate for innovation positively predicts team creativity, (4) shared leadership predicts team creativity through the mediating effect of a climate for innovation, and (5) this mediation effect is stronger when task uncertainty is high. Theoretical and practical implications are discussed.

Academia Letters, 2021

The main purpose of this report is to review the Environmental Impact Assessment (EIA) of Modunag... more The main purpose of this report is to review the Environmental Impact Assessment (EIA) of Modunaghat Water Treatment Plant (WTP), finding gaps in the report with the solutions. The history of the Modunaghat WTP was assessed and the EIA was analyzed. After analyzing the EIA of the plant, issues and problems were identified and recommendation were provided including the challenges. Checklist and matrix methods were used to perform the EIA of Modunaghat WTP. Network method was suggested as the EIA methodology. The final recommendation was to consult with the fishermen on timely basis to analyze fish breeding situation of the Halda river.

Proceedings of the 20th International Middleware Conference Industrial Track, 2019

During the past few years, all leading cloud providers introduced burstable instances that can sp... more During the past few years, all leading cloud providers introduced burstable instances that can sprint their performance for a limited period to address sudden workload variations. Despite the availability of burstable instances, there is no clear understanding of how to minimize the waste of resources by regulating their burst capacity to the workload requirements. This is especially true when it comes to non-CPU-intensive applications. In this paper, we investigate how to limit network and I/O usage to optimize the efficiency of the bursting process. We also study which resource shall be controlled to benefit both cloud providers and end-users. We design MRburst (Multi-Resource burstable performance scheduler) to automatically limit multiple resources (i.e., network, I/O, and CPU) and make the application comply with a user-defined service level objective (SLO) while minimizing wasted resources. MRburst is evaluated on Amazon EC2 using two multi-resource applications: an FTP server and a Ceph system. Experimental results show that MRburst outperforms state-of-the-art approaches by allowing instances to speed up their performance for up to 2.4 times longer period while meeting SLO.

Want to know how to use an electronic component? This second book of a three-volume set includes ... more Want to know how to use an electronic component? This second book of a three-volume set includes key information on electronics parts for your projects--complete with photographs, schematics, and diagrams. You'll learn what each one does, how it works, why it's useful, and what variants exist. No matter how much you know about electronics, you'll find fascinating details you've never come across before.Perfect for teachers, hobbyists, engineers, and students of all ages, this reference puts reliable, fact-checked information right at your fingertips--whether you're refreshing your memory or exploring a component for the first time. Beginners will quickly grasp important concepts, and more experienced users will find the specific details their projects require.Volume 2 covers signal processing, including LEDs, LCDs, audio, thyristors, digital logic, and amplification.Unique: the first and only encyclopedia set on electronic components, distilled into three separat...

Software Defined Networking (SDN) decouples the control plane from the data plane, thereby facili... more Software Defined Networking (SDN) decouples the control plane from the data plane, thereby facilitates network virtualization, dynamic programmability and flexibility in network management. Earlier works on SDN modeling only focused on packet-level arrivals without considering flow-level arrivals. However, the model without considering flow-level arrivals cannot correctly reflect the probability of packets sent to the controller. In this paper, we propose an analytical model (4D state) which consider flow-level (UDP flow) arrivals and packet-level arrivals simultaneously. Our analytical model (4D state) use fourdimensional states to evaluate the steady state probability. We have derived analytical formulas of average packet delay and packet loss probability for UDP flows in SDN. We have conducted numerical analysis and extensive simulations. Our results show good matches, which verify the suitability and correctness of our analysis. Error ratio of the analytical results for 4D state...