Papers by Prof.Amjad Al-Nasser
The international journal of organizational analysis, Jul 13, 2015
Purpose– The purpose of this study is to establish both the validity of Western theories within t... more Purpose– The purpose of this study is to establish both the validity of Western theories within the Middle East, namely, the United Arab Emirates (UAE), and to further improve and extend our understanding of the effect of organisational coaching on counterproductive behaviours, such as bullying and alienation.Design/methodology/approach– A sample size of 656 participants from 29 organisations and 14 different industries was employed. A research model was proposed, refined and tested through a quantitative paradigm using one dimension nonlinear principal components analysis, linear structural equation modelling (SEM) and MANOVA.Findings– The correlation analysis results show non-significant negative correlations between coaching and all of the organisational counterproductive behaviour dimensions but not certainty. It was found that a significant weak relationship exists between most of the mediator dimensions, while a strong relationship exists between job alienation and workplace bullying. Results of the linear SEM provide support that coaching is related to certainty. Furthermore, the results reveal that certainty mediates a significant link between coaching and organisational counterproductive work behaviours (job alienation and bullying).Originality/value– The study is considered the first in the UAE to investigate organisational counterproductive work behaviours (bullying and job alienation). The main contribution of this study is to quantify the relationship between organisational coaching and bullying and job alienation mediated by organisational climate dimensions.
Journal of Taibah University for Science, Oct 31, 2022
Journal of Applied Statistics, Aug 6, 2019
ABSTRACT In this study, we propose a new single acceptance sampling plan from truncated life test... more ABSTRACT In this study, we propose a new single acceptance sampling plan from truncated life test assuming that the quality characteristics follow the Tsallis q-exponential distribution. The proposed plan is given, and then we derived the operation characteristics function and calculate the optimal sample size and producer’'s risk for some given parameter values to measure the performance of this plan. Also, a comparative study with other sampling plan is discussed to show the benefit of the proposed plan, and real data analysis is given to illustrate the applicability of the proposed plan in the industry.
RePEc: Research Papers in Economics, Mar 10, 2005
Genetic Testing and Molecular Biomarkers, 2011
The activity of the methylenetetrahydrofolate reductase (MTHFR) enzyme is regulated by the two po... more The activity of the methylenetetrahydrofolate reductase (MTHFR) enzyme is regulated by the two polymorphisms C677T and A1298C, which reduce enzyme activity and result in hypomethylation of chromosomes that increase the risk of nondisjunction. These polymorphisms are suggested to be risk factors for Down syndrome (DS) in some populations. The aim of this study was to test if C677T and A1298C polymorphisms are correlated to maternal risk of DS in Jordan. The proportions of C677T and A1298C polymorphisms were examined in 53 case mothers who delivered DS children and 29 controls. The median age of case mothers was 35 years when delivering their affected children. Polymerase chain reaction-restriction fragment length polymorphism was used for genotyping. The frequency of MTHFR C677T allele in all DS mothers was 3.2-fold higher than in the controls (odds ratio [OR] = 3.12, 95% confidence interval [CI]: 1.303-7.677). Also, the proportion of 677T in the older case mothers was different from the controls, but was significantly higher in younger case mothers than in the controls (OR = 4.2, 95% CI: 1.61-10.97, p = 0.003). The proportions of 677CT and 677TT genotypes in younger cases are, respectively, 10- and 9-fold higher than in the controls. The proportions of MTHFR A1298C are significantly different among all case groups and the controls (χ(2) = 4.27, p = 0.127), but there was a significant difference between young case mothers and both older case mothers group and the controls (OR = 1.25, 95% CI: 0.405-3.85, p = 0.698). There is strong association between MTHFRC677T and maternal risk of DS in Jordanian mothers younger than 35 years old and the MTHFR1298C allele has a lesser but additive risk effect in MTHFR677T/1298C compound heterozygotes.
Pathogens, 2020
In December 2019, a cluster of fatal pneumonia cases presented in Wuhan, China. They were caused ... more In December 2019, a cluster of fatal pneumonia cases presented in Wuhan, China. They were caused by a previously unknown coronavirus. All patients had been associated with the Wuhan Wholefood market, where seafood and live animals are sold. The virus spread rapidly and public health authorities in China initiated a containment effort. However, by that time, travelers had carried the virus to many countries, sparking memories of the previous coronavirus epidemics, severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS), and causing widespread media attention and panic. Based on clinical criteria and available serological and molecular information, the new disease was called coronavirus disease of 2019 (COVID-19), and the novel coronavirus was called SARS Coronavirus-2 (SARS-CoV-2), emphasizing its close relationship to the 2002 SARS virus (SARS-CoV). The scientific community raced to uncover the origin of the virus, understand the pathogenesis of the dise...
Journal of Quantitative Methods, 2019
Journal of Modern Applied Statistical Methods, 2004
This article deals with multiple linear functional relationships models. Two robust estimations p... more This article deals with multiple linear functional relationships models. Two robust estimations procedure are proposed to estimate the model, based on Generalized Maximum Entropy and Partial Least Square. They are distribution free and do not rely (so much) on classical assumptions. The experiments showed that the GME approach outperforms the PLS in terms of mean squares of errors (MSE). Empirical examples are studied.
Jordan Journal of Civil Engineering, 2011
In this paper, we analyze the emissions caused by private gasoline vehicles based on a random sam... more In this paper, we analyze the emissions caused by private gasoline vehicles based on a random sample of 950 vehicles. Different types of pollutants; carbon monoxide (CO), carbon dioxide (CO 2) and hydrocarbon (HC) were analyzed based on the Jordanian emission standards with special reference to three different vehicles' manufacturing countries; namely: Korea, Japan and Germany. The analysis results indicated that Korean made vehicles gave better results than Japanese and German made ones on superiority to pass the tests of vehicles' emission. The results indicated that at a significance value of 0.05 there was a statistical relationship between Japanese vehicles and model year, engine capacity, vehicle fuel supply system and periodic maintenance. Also, for German vehicles there was a statistical relationship between manufacturing year, fuel type and fuel supply system. However, Korean vehicles showed a statistical relationship only with the fuel supply system. Overall, all vehicles should have an injection system in order to reduce exhausts' emissions, and the vehicles should be as new as possible. It should also be recommended not to import vehicles with carburetor fuel supply system.
The International Journal of Human Resource Management, 2016
The University of Gloucestershire accepts no liability for any infringement of intellectual prope... more The University of Gloucestershire accepts no liability for any infringement of intellectual property rights in any material deposited but will remove such material from public view pending investigation in the event of an allegation of any such infringement.
Journal of Applied Mathematics and Decision Sciences, 2005
Journal of Modern Applied Statistical Methods, Jul 28, 2020
A single acceptance sampling plan for the three-parameter Lindley distribution under a truncated ... more A single acceptance sampling plan for the three-parameter Lindley distribution under a truncated life test is developed. For various consumer's confidence levels, acceptance numbers, and values of the ratio of the experimental time to the specified average lifetime, the minimum sample size important to assert a certain average lifetime are calculated. The operating characteristic (OC) function values as well as the associated producer's risks are also provided. A numerical example is presented to illustrate the suggested acceptance sampling plans.
Soft Computing, Sep 25, 2019
In this paper, data concerning MILANO EXPO2015 is collected from the official twitter page of the... more In this paper, data concerning MILANO EXPO2015 is collected from the official twitter page of the event before and after its opening. In order to extract a semi-supervised ontology and to evaluate the global sentiment around the event, a variety of language processing techniques has been applied on the collected "tweets": Latent Semantic Analysis, sentiment polarity tracking, along with gap analysis has allowed the semantic evaluation of users' opinions. Moreover, the generalized cross entropy approach has been applied for the first time on web data, adding prior information on the effect of semantic classes on the global sentiment, improving accuracy and adding detail to the analysis.
Pakistan Journal of Statistics and Operation Research, Jun 2, 2023
In this paper, a new generalization of one parameter Lindely distribution is proposed. The new di... more In this paper, a new generalization of one parameter Lindely distribution is proposed. The new distribution is a mixture distribution of Gamma distributions with fixed scale parameter and variable shape parameter. The distribution is called 'GOLD Distribution' as it is a generalization for several distributions such as exponential, Lindely, Sujatha, Amarendra, Devya and Shambhu distributions. The probability density and cumulative density functions are derived. Also, the statistical properties of the GOLD distribution are discussed. Parameter estimation using the maximum likelihood and the method of moments are given. Moreover, an illustration of the usefulness of the GOLD distribution in survival data analysis is discussed based on a real lifetime data.
Electronic Journal of Applied Statistical Analysis, Feb 11, 2016
In this study, a new acceptance sampling plan based on truncated life test is proposed for a life... more In this study, a new acceptance sampling plan based on truncated life test is proposed for a lifetime following a New Weibull-Pareto distribution (NWPD). For various acceptance numbers, confidence levels and values of the ratio of the fixed experiment time to the particular mean lifetime as well as the minimum sample sizes required to assert the specified mean life are found. The operating characteristic function values of the suggested sampling plans and producer's risk are presented. The important tables are presented and the results are explained by a discussing the results of numerical examples.
Statistics in Transition New Series, Sep 1, 2021
In this research, a new acceptance sampling plan for a truncated life test is presented, assuming... more In this research, a new acceptance sampling plan for a truncated life test is presented, assuming that the quality characteristic follows the power Lomax distribution. The operating characteristic function values are calculated for the proposed sampling plan, jointly with the optimal sample size and the producer's risk for a selection of distribution parameters. Furthermore, a comparative study with other sampling plans is introduced to demonstrate the advantages of the proposed plan. Finally, a real-life example illustrating the applicability of the proposed sampling plan in a manufacturing company is discussed.
Stochastics and quality control, Jun 1, 2017
A double acceptance sampling plan (DASP) based on truncated life tests is suggested in this paper... more A double acceptance sampling plan (DASP) based on truncated life tests is suggested in this paper when the lifetime of a product follows the exponentiated generalized inverse Rayleigh distribution (EGIR). For a fixed value of the consumer’s confidence level, the minimum sample sizes of the first and second samples needed to ensure the specified mean life are obtained. The operating characteristic values according to the different quality levels are obtained and the minimum ratios of the mean life to the specified life are calculated. The important tables based on the suggested DASP are calculated and illustrated.
Afrika Matematika, Feb 20, 2018
We develop a ranked acceptance sampling plan by attribute for exponential distribution assuming t... more We develop a ranked acceptance sampling plan by attribute for exponential distribution assuming that the life test is truncated at a pre-assigned time. Two main requirements are essential for the proposed ranked sampling plans; namely; the life times of the test units are assumed to follow the exponential distribution; and the data are selected by using a free cost sampling method, the median ranked set sampling scheme from a large lot. The main advantage of using the median rank set sampling is to reduce producer's risk, and it is one of the ranked scheme that produces a judgment order statistics that are mutually independent and identically distributed random variables to meet the binomial theory assumptions. The distribution function characterization under the median ranked set sampling scheme is derived assuming that the set size is known; then the minimum sample size necessary to ensure the specified average life are obtained and the operating characteristic values of the sampling plans based on the ranked samples and producer's risk are presented. A comparisons with sampling plan based on simple random sampling and an illustrative example are given.
Ranked Set Sampling
Abstract In this chapter, the design of the Shewhart control chart based on ranked repetitive sam... more Abstract In this chapter, the design of the Shewhart control chart based on ranked repetitive sampling is presented. The structure of the proposed control chart is given for the quality characteristic and follows the normal distribution. The necessary measures of this chart are given to assess its performance. The performance of the chart is evaluated using the average run length over the existing control chart. The application of the chart is given through simulation and a real example.
Pesquisa Operacional, 2020
In this paper, we proposed a new ranked data control chart using repetitive sampling criterion to... more In this paper, we proposed a new ranked data control chart using repetitive sampling criterion to increase the performance of detecting any shift in mean process. For the comparisons target, the average run length (ARL) of the proposed control chart based on repetitive extreme ranked set sampling computed using exact and estimated parameters. The results showed that the ARL affected negatively by the parameter estimation. Moreover, the performances of the proposed control chart is evaluated and compared with similar control chart that obtained by using different sampling schemes such as the simple random sampling, ranked set sampling, extreme ranked set sampling and repetitive ranked set sampling.. The results showed that the ranked data based control chart outperform the classical control chart in terms of the ARL.
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Papers by Prof.Amjad Al-Nasser