Your search for: 'author:("Saleem, Muhammad")' has returned 8 results. (0.028s) Save search

Authors: Saleem, Muhammad | Sharif, Kashif | Fahmi, Aliya

Article Type: Research Article

Abstract: Applications of Pareto distribution are common in reliability, survival and financial studies. In this paper, A Pareto mixture distribution is considered to model a heterogeneous population comprising of two subgroups. Each of two subgroups is characterized by the same functional form with unknown distinct shape and scale parameters. Bayes estimators have been derived using flat and conjugate priors using squared error loss function. Standard errors have also been derived for the Bayes estimators. An interesting feature of this study is the preparation of components of Fisher Information matrix.

Keywords: Maximum likelihood estimators, Fisher information matrix, Bayes estimators, uninformative priors, informative priors, predictive intervals, right censoring, probabilistic mixing

DOI: 10.3233/JIN-180082

Citation: Journal of Integrative Neuroscience, vol. 17, no. 3-4, pp. 463-477, 2018

Authors: Saleem, Muhammad | Khan, Yasar | Hasnain, Ali | Ermilov, Ivan | Ngonga Ngomo, Axel-Cyrille

Article Type: Research Article

Abstract: The Web of Data has grown enormously over the last years. Currently, it comprises a large compendium of interlinked and distributed datasets from multiple domains. Running complex queries on this compendium often requires accessing data from different endpoints within one query. The abundance of datasets and the need for running complex query has thus motivated a considerable body of work on SPARQL query federation systems, the dedicated means to access data distributed over the Web of Data. However, the granularity of previous evaluations of such systems has not allowed deriving of insights concerning their behavior in different steps involved during …federated query processing. In this work, we perform extensive experiments to compare state-of-the-art SPARQL endpoint federation systems using the comprehensive performance evaluation framework FedBench. In addition to considering the tradition query runtime as an evaluation criterion, we extend the scope of our performance evaluation by considering criteria, which have not been paid much attention to in previous studies. In particular, we consider the number of sources selected, the total number of SPARQL ASK requests used, the completeness of answers as well as the source selection time. Yet, we show that they have a significant impact on the overall query runtime of existing systems. Moreover, we extend FedBench to mirror a highly distributed data environment and assess the behavior of existing systems by using the same performance criteria. As the result we provide a detailed analysis of the experimental outcomes that reveal novel insights for improving current and future SPARQL federation systems. Show more

Keywords: SPARQL federation, Web of Data, RDF

DOI: 10.3233/SW-150186

Citation: Semantic Web, vol. 7, no. 5, pp. 493-518, 2016

Authors: Khan, Muhammad Adnan | Umair, Muhammad | Saleem, Muhammad Aamer | Ali, Muhammad Nadeem | Abbas, Sagheer

Article Type: Research Article

Abstract: In modern communication, MIMO technology appeared to be one of the important technologies. System capacity and service quality are enhanced by using this technology. The mission of both channel and data estimation based on the principle of maximum likelihood is achieved by means of continuous and discrete TOMPSO algorithm over Rayleigh Fading Channel. The algorithm has three levels. At the first stage, channel and data populations are prepared. The continuous TOMPSO is using to estimate channel parameters at the second stage. Once the channel is estimated, it is used at stage 3 along with discrete TOMPSO to estimate transmitted symbols. …It is observed that due to included total opposite based learning of swarmand velocity factor the TOMPSO gives a fast convergence rate and attractive results in terms of MMSE and MMCE. Show more

Keywords: MIMO, TOMPSO, BER, MMSE, MMCE

DOI: 10.3233/JIFS-181127

Citation: Journal of Intelligent & Fuzzy Systems, vol. 37, no. 1, pp. 687-692, 2019

Authors: Ullah, Sami | Kashif, Muhammad | Aslam, Muhammad | Haider, Gulfam | AlAita, Abdulrahman | Saleem, Muhammad

Article Type: Research Article

Abstract: The application of classical statistical methods is not feasible given the presence of imprecise, fuzzy, uncertain, or undetermined observations in the underlying dataset. This is due to the existence of uncertainties pervading every aspect of real-life situations, which cannot always be accurately addressed by classical statistical approaches. In order to tackle this problem, a new methodology known as neutrosophic analysis of variance (NANOVA) has been developed as an extension of classical approaches to analyze datasets with uncertainty. The proposed approach can be applied regardless of the number of factors and replications. Moreover, NANOVA introduces a novel matrix-based approach to derive …the F_N-test in an uncertain environment. To assess the effectiveness of NANOVA, various real datasets have been employed, and research findings on single- and two-factor NANOVAs with measures of indeterminacy have been presented. According to our comparisons, NANOVA provides a more informative, efficient, flexible, and reliable approach to deal with uncertainties than classical statistical methods. Therefore, there is a need to go beyond conventional statistical techniques and adopt advanced methodologies that can effectively handle uncertainties. Show more

Keywords: Imprecise data, classical statistics, interval statistics, analysis of variance, F-test

DOI: 10.3233/JIFS-223636

Citation: Journal of Intelligent & Fuzzy Systems, vol. 45, no. 4, pp. 6005-6017, 2023

Authors: Qudus, Umair | Saleem, Muhammad | Ngonga Ngomo, Axel-Cyrille | Lee, Young-Koo

Article Type: Research Article

Abstract: Finding a good query plan is key to the optimization of query runtime. This holds in particular for cost-based federation engines, which make use of cardinality estimations to achieve this goal. A number of studies compare SPARQL federation engines across different performance metrics, including query runtime, result set completeness and correctness, number of sources selected and number of requests sent. Albeit informative, these metrics are generic and unable to quantify and evaluate the accuracy of the cardinality estimators of cost-based federation engines. To thoroughly evaluate cost-based federation engines, the effect of estimated cardinality errors on the overall query runtime performance …must be measured. In this paper, we address this challenge by presenting novel evaluation metrics targeted at a fine-grained benchmarking of cost-based federated SPARQL query engines. We evaluate five cost-based federated SPARQL query engines using existing as well as novel evaluation metrics by using LargeRDFBench queries. Our results provide a detailed analysis of the experimental outcomes that reveal novel insights, useful for the development of future cost-based federated SPARQL query processing engines. Show more

Keywords: SPARQL, benchmarking, cost-based, cost-free, federated, querying

DOI: 10.3233/SW-200420

Citation: Semantic Web, vol. 12, no. 6, pp. 843-868, 2021

Authors: Rabbani, Ghulam | Isab, Anvarhusein A. | Al-Arfaj, Abdul Rahman | Ahmad, Saeed | Saleem, Muhammad | Hameed, Abdul | Akbar, Erum

Article Type: Research Article

Abstract: Mercury(II) complexes of thiolates having the general formula [Hg(RS)Cl2 ]− and [Hg(RS)2 ] have been prepared and characterized by IR and NMR (1 H and 13 C) spectroscopy (RSH = 2-aminoethanethiol hydrochloride (Aet), cysteine (Cys), thiosalicylic acid (Ts) and 2-mercaptonicotinic acid (Mnt)). The spectral data suggests that the coordination of thiolates to mercury(II) occurs through the sulfur as indicated by the absence of S–H vibrations in IR and significant downfield shifts in the C–S resonance in 13 C NMR. However, in Mnt complexes, coordination through both sulfur and nitrogen is indicated. Antimicrobial activities of the complexes were evaluated by minimum …inhibitory concentration and the results showed that the complexes exhibited a wide range of activities against gram-negative bacteria (E. coli, P. aeruginosa), while moderate activity was observed against a mold, P. citrinum. Show more

Keywords: Mercury(II), thiolates, NMR spectroscopy, antimicrobial activity

DOI: 10.3233/SPE-2009-0369

Citation: Spectroscopy, vol. 23, no. 1, pp. 45-50, 2009

Authors: Stadler, Claus | Saleem, Muhammad | Mehmood, Qaiser | Buil-Aranda, Carlos | Dumontier, Michel | Hogan, Aidan | Ngonga Ngomo, Axel-Cyrille

Article Type: Research Article

Abstract: We present the Linked SPARQL Queries (LSQ) dataset, which currently describes 43.95 million executions of 11.56 million unique SPARQL queries extracted from the logs of 27 different endpoints. The LSQ dataset provides RDF descriptions of each such query, which are indexed in a public LSQ endpoint, allowing interested parties to find queries with the characteristics they require. We begin by describing the use cases envisaged for the LSQ dataset, which include applications for research on common features of queries, for building custom benchmarks, and for designing user interfaces. We then discuss how LSQ has been used in practice since the …release of four initial SPARQL logs in 2015. We discuss the model and vocabulary that we use to represent these queries in RDF. We then provide a brief overview of the 27 endpoints from which we extracted queries in terms of the domain to which they pertain and the data they contain. We provide statistics on the queries included from each log, including the number of query executions, unique queries, as well as distributions of queries for a variety of selected characteristics. We finally discuss how the LSQ dataset is hosted and how it can be accessed and leveraged by interested parties for their use cases. Show more

Keywords: SPARQL, Query Log Analysis, Web of Data, RDF

DOI: 10.3233/SW-223015

Citation: Semantic Web, vol. 15, no. 1, pp. 167-189, 2024

Authors: Usbeck, Ricardo | Yan, Xi | Perevalov, Aleksandr | Jiang, Longquan | Schulz, Julius | Kraft, Angelie | Möller, Cedric | Huang, Junbo | Reineke, Jan | Ngonga Ngomo, Axel-Cyrille | Saleem, Muhammad | Both, Andreas

Article Type: Research Article

Abstract: Knowledge Graph Question Answering (KGQA) has gained attention from both industry and academia over the past decade. Researchers proposed a substantial amount of benchmarking datasets with different properties, pushing the development in this field forward. Many of these benchmarks depend on Freebase, DBpedia, or Wikidata. However, KGQA benchmarks that depend on Freebase and DBpedia are gradually less studied and used, because Freebase is defunct and DBpedia lacks the structural validity of Wikidata. Therefore, research is gravitating toward Wikidata-based benchmarks. That is, new KGQA benchmarks are created on the basis of Wikidata and existing ones are migrated. We present a new, …multilingual, complex KGQA benchmarking dataset as the 10th part of the Question Answering over Linked Data (QALD) benchmark series. This corpus formerly depended on DBpedia. Since QALD serves as a base for many machine-generated benchmarks, we increased the size and adjusted the benchmark to Wikidata and its ranking mechanism of properties. These measures foster novel KGQA developments by more demanding benchmarks. Creating a benchmark from scratch or migrating it from DBpedia to Wikidata is non-trivial due to the complexity of the Wikidata knowledge graph, mapping issues between different languages, and the ranking mechanism of properties using qualifiers. We present our creation strategy and the challenges we faced that will assist other researchers in their future work. Our case study, in the form of a conference challenge, is accompanied by an in-depth analysis of the created benchmark. Show more

Keywords: Knowledge graph question answering, benchmark, challenge, query analysis

DOI: 10.3233/SW-233471

Citation: Semantic Web, vol. Pre-press, no. Pre-press, pp. 1-15, 2023