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Article
Publication date: 15 June 2012

Hooran MahmoudiNasab and Sherif Sakr

The purpose of this paper is to present a two‐phase approach for designing an efficient tailored but flexible storage solution for resource description framework (RDF) data based…

Abstract

Purpose

The purpose of this paper is to present a two‐phase approach for designing an efficient tailored but flexible storage solution for resource description framework (RDF) data based on its query workload characteristics.

Design/methodology/approach

The approach consists of two phases. The vertical partitioning phase which aims of reducing the number of join operations in the query evaluation process, while the adjustment phase aims to maintain the efficiency of the performance of the query processing by adapting the underlying schema to cope with the dynamic nature of the query workloads.

Findings

The authors perform comprehensive experiments on two real‐world RDF datasets to demonstrate that the approach is superior to the state‐of‐the‐art techniques in this domain.

Originality/value

The main motivation behind the authors' approach is that several benchmarking studies have recently shown that each RDF dataset requires a tailored table schema in order to achieve efficient performance during query processing. None of the previous approaches have considered this limitation.

Details

International Journal of Web Information Systems, vol. 8 no. 2
Type: Research Article
ISSN: 1744-0084

Keywords

Article
Publication date: 22 June 2010

Sherif Sakr and Ghazi Al‐Naymat

The purpose of this paper is to provide a detailed discussion for different types of graph queries and a different mechanism for indexing and querying graph databases.

1154

Abstract

Purpose

The purpose of this paper is to provide a detailed discussion for different types of graph queries and a different mechanism for indexing and querying graph databases.

Design/methodology/approach

The paper reviews the existing approaches and techniques for indexing and querying graph databases. For each approach, the strengths and weaknesses are discussed with particular emphasis on the target application domain. Based on an analysis of the state‐of‐the‐art of research literature, the paper provides insights for future research directions and untouched challenging research aspects.

Findings

Several graph indexing and querying techniques have been proposed in the literature. However, there is still a clear room for improvement and further research issues in that domain.

Research limitations/implications

The paper identifies the advantages and disadvantages of the different graph indexing mechanisms and their suitability for different practical applications. The paper provides some guidelines and recommendations which are useful for future research in the area of graph databases.

Practical implications

The paper has practical implications for social networks, protein networks, chemical compounds, multimedia database, and semantic web.

Originality/value

The paper contributes to the implementation of an efficient indexing and querying mechanism for graph databases in different application domains.

Details

International Journal of Web Information Systems, vol. 6 no. 2
Type: Research Article
ISSN: 1744-0084

Keywords

Article
Publication date: 4 April 2008

Sherif Sakr

Estimating the sizes of query results and intermediate results is crucial to many aspects of query processing. All database systems rely on the use of cardinality estimates to…

1604

Abstract

Purpose

Estimating the sizes of query results and intermediate results is crucial to many aspects of query processing. All database systems rely on the use of cardinality estimates to choose the cheapest execution plan. In principle, the problem of cardinality estimation is more complicated in the Extensible Markup Language (XML) domain than the relational domain. The purpose of this paper is to present a novel framework for estimating the cardinality of XQuery expressions as well as their sub‐expressions. Additionally, this paper proposes a novel XQuery cardinality estimation benchmark. The main aim of this benchmark is to establish the basis of comparison between the different estimation approaches in the XQuery domain.

Design/methodology/approach

As a major innovation, the paper exploits the relational algebraic infrastructure to provide accurate estimation in the context of XML and XQuery domains. In the proposed framework, XQuery expressions are translated into an equivalent relational algebraic plans and then using a well defined set of inference rules and a set of special properties of the algebraic plan, this framework is able to provide high‐accurate estimation for XQuery expressions.

Findings

This paper is believed to be the first which provides a uniform framework to estimate the cardinality of more powerful XML querying capabilities using XQuery expressions as well as their sub‐expressions. It exploits the relational algebraic infrastructure to provide accurate estimation in the context of XML and XQuery domains. Moreover, the proposed framework can act as a meta‐model through its ability to incorporate different summarized XML structures and different histogram techniques which allows the model designers to achieve their targets by focusing their effort on designing or selecting the adequate techniques for them. In addition, this paper proposes benchmark for XQuery cardinality estimation systems. The proposed benchmark distinguishes itself from the other existing XML benchmarks in its focus on establishing the basis for comparing the different estimation approaches in the XML domain in terms of their accuracy of the estimations and their completeness in handling different XML querying features.

Research limitations/implications

The current status of this proposed XQuery cardinality estimations framework does not support the estimation of the queries over the order information of the source XML documents and does not support non‐numeric predicates.

Practical implications

The experiments of this XQuery cardinality estimation system demonstrate its effectiveness and show high‐accurate estimation results. Utilizing the cardinality estimation properties during the SQL translation of XQuery expression results in an average improvement of 20 percent on the performance of their execution times.

Originality/value

This paper presents a novel framework for estimating the cardinality of XQuery expressions as well as its sub‐expressions. A novel XQuery cardinality estimation benchmark is introduced to establish the basis of comparison between the different estimation approaches in the XQuery domain.

Details

International Journal of Web Information Systems, vol. 4 no. 1
Type: Research Article
ISSN: 1744-0084

Keywords

Content available
Article
Publication date: 22 June 2010

David Taniar

336

Abstract

Details

International Journal of Web Information Systems, vol. 6 no. 2
Type: Research Article
ISSN: 1744-0084

Content available
Article
Publication date: 20 November 2009

398

Abstract

Details

International Journal of Web Information Systems, vol. 5 no. 4
Type: Research Article
ISSN: 1744-0084

Article
Publication date: 17 October 2023

Adhi Alfian, Hamzah Ritchi and Zaldy Adrianto

Increased fraudulent practices have heightened the need for innovation in anti-fraud programs, necessitating the development of analytics techniques for detecting and preventing…

Abstract

Purpose

Increased fraudulent practices have heightened the need for innovation in anti-fraud programs, necessitating the development of analytics techniques for detecting and preventing fraud. The subject of fraud analytics will continue to expand in the future for public-sector organizations; therefore, this research examined the progress of fraud analytics in public-sector transactions and offers suggestions for its future development.

Design/methodology/approach

This study systematically reviewed research on fraud analytics development in public-sector transactions. The review was conducted from June 2021 to June 2023 by identifying research objectives and questions, performing literature quality assessment and extraction, data synthesis and research reporting. The research mainly identified 43 relevant articles that were used as references.

Findings

This research examined fraud analytics development related to public-sector financial transactions. The results revealed that fraud analytics expansion has not spread equally, as most programs have been implemented by governments and healthcare organizations in developed countries. This research also exposed that the analytics optimization in fraud prevention is higher than for fraud detection. Such analytics help organizations detect fraud, improve business effectiveness and efficiency, and refine administrative systems and work standards.

Research limitations/implications

This research offers comprehensive insights for researchers and public-sector professionals regarding current fraud analytics development in public-sector financial transactions and future trends.

Originality/value

This study presents the first systematic literature review to investigate the development of fraud analytics in public-sector transactions. The findings can aid scholars' and practitioners' future fraud analytics development.

Details

Journal of Public Budgeting, Accounting & Financial Management, vol. 35 no. 5
Type: Research Article
ISSN: 1096-3367

Keywords

Article
Publication date: 30 August 2021

Olugbenga Timo Oladinrin and Lekan Damilola Ojo

The detrimental impacts of the construction industry activities, namely, toxicity of cement and concrete to the health of construction workers and the general public, have been…

Abstract

Purpose

The detrimental impacts of the construction industry activities, namely, toxicity of cement and concrete to the health of construction workers and the general public, have been reported in previous studies. Several environmental management measures were put in place by international organisations to reduce these impacts on humans and the entire ecosystem. Sadly, such environmental management measures are not widely embraced in the construction industry of developing countries. This contributes to the poor quality of life of construction stakeholders, amongst other outcomes. Therefore, this study investigated the drivers to facilitate an environmental management system (EMS) in the Nigerian construction industry (NCI).

Design/methodology/approach

questionnaires retrieved from construction professionals in the micro, small, medium and large enterprises were used to conduct both descriptive and inferential statistics, namely, mean score, standard deviation, Kruskal–Wallis H test, post hoc test and factor analysis.

Findings

The analyses show that the drivers of EMS implementation in the NCI could be grouped into intellectual enhancement strategies, documentation and cultural strategies, and motivation and tracking strategies. The study concluded that training and education of relevant stakeholders, tracking compliance levels of organisations and recognising firms acting in compliance with stipulated “environmental” policy are essential. It was recommended that the collaboration of all construction stakeholders be upheld to aid EMS implementation in the NCI.

Originality/value

This paper investigated the drivers of EMS with the opinions of construction professionals in the mainstream of the NCI through survey using to ensure wide coverage of respondents. Investigating the view of construction professionals in the micro, small, medium and large enterprises helped determine possible significant differences. Thus, practical implications of the study were also provided in a systematic manner.

Details

Engineering, Construction and Architectural Management, vol. 29 no. 10
Type: Research Article
ISSN: 0969-9988

Keywords

Article
Publication date: 13 July 2012

A.A. Javadi, M.M. Sherif and H.F. Abd‐Elhamid

Seawater intrusion represents a major problem in many coastal aquifers all over the world. It degrades the water‐quality and hence the groundwater may become unsuitable for…

Abstract

Purpose

Seawater intrusion represents a major problem in many coastal aquifers all over the world. It degrades the water‐quality and hence the groundwater may become unsuitable for domestic and agriculture purposes. Due to the direct hydraulic contact between the freshwater and saline water in coastal aquifers and the density difference between the two water bodies, the seawater migrates inland. The problem is exacerbated when the groundwater abstraction rates exceed the natural recharge from rainfall events. The key to controlling this problem is to maintain the proper balance between water being pumped from the aquifer and the amount of water recharging it. The purpose of this paper is to present a coupled transient finite element model for simulation of fluid flow and solute transport in soils with application to study seawater intrusion in coastal aquifers.

Design/methodology/approach

The model includes coupling of fluid flow and solute transport. Transient density‐dependent flow and the dependency of dispersion on velocity are considered. After validation, the model is applied to predict the seawater intrusion in the Wadi Ham aquifer, UAE in vertical sections and the results are compared with those from a commercial code (SEWAT) which was used to simulate seawater intrusion in the aquifer in a horizontal section.

Findings

A good agreement is observed between the results of the current model in the vertical cross‐section and those of SEWAT in the horizontal cross‐section for the case of Wadi Ham. The results show that the model can predict the extent of seawater intrusion (and the transition zone) and distribution of salt concentration in the aquifer with a good accuracy.

Originality/value

The developed model includes coupling of fluid flow and solute transport in saturated and unsaturated porous media. Transient density‐dependent flow and the dependency of dispersion on velocity are considered. The model has been applied to a real world case study. A combination of the results in vertical and horizontal sections has been used to build a 3D picture of seawater intrusion in the aquifer.

Article
Publication date: 12 August 2019

Abdelrahman Moukhtar Naser, Hamada Abd El - Wahab, Mohamed Abd El Fattah Moustafa El Nady, Abdelzaher E.A. Mostafa, Long Lin and Ahmed Galal Sakr

This paper aims to investigate the best methods of utilisation of reclaimed asphalt pavements (RAP) in Egypt, to determine the effect of using 100% RAP instead of using virgin…

196

Abstract

Purpose

This paper aims to investigate the best methods of utilisation of reclaimed asphalt pavements (RAP) in Egypt, to determine the effect of using 100% RAP instead of using virgin aggregates and asphalt; investigate the effect of thermoplastic elastomer polymer as asphalt modifier; and also improve the mechanical and physical characteristics and consequently improving the quality of asphalt paving, increasing service life of asphalt-paving and reducing costs.

Design/methodology/approach

Nano acrylate terpolymers were prepared with different % (Wt.) of and were characterised by Fourier transforms infrared (FTIR), for molecular weight (Mw), by thermo gravimetric analysis (TGA) and by transmission electron microscopy (TEM). A 4% (Wt.) of the prepared nanoemulsion terpolymer was mixed with virgin asphalt as a polymer modifier, to improve and reuse of the RAP. The modified binder was tested. The tests conducted include penetration, kinematic viscosity, softening point and specific gravity. Application of Marshall mix design types; hot mix asphalt (HMA), warm mix asphalt (WMA) and cold in place recycled (CIR). Four different mix designs used; control mix contained virgin asphalt by HMA, and the other three mix designs were polymermodified asphalt sample by HMA, WMA and CIR.

Findings

The research results showed that using 4 Wt.% of the prepared nanoemulsion terpolymer to produce hot mix asphalt (HMA) and warm mix asphalt (WMA) achieved higher stability compared to the control mix and cold in place recycled (CIR).

Research limitations/implications

This paper discusses the preparation and the characterisation of nanoemulsion and its application in RAPs to enhance and improve the RAP quality.

Practical implications

Nano-acrylate terpolymer can be used as a new polymer to modify asphalt to achieve the required specifications for RAP.

Originality/value

According to the most recent surveys, Europe produced 265 tonnes of asphalt for road applications in 2014, while the amount of available RAP was more than 50 tonnes. The use of RAP in new blended mixes reduces the need of neat asphalt, making RAP recycling economically attractive.

Article
Publication date: 13 May 2020

H. Abd El-Wahab, G.A. Meligi, M.G. Hassaan and L. Lin

The purpose of this study is to prepare, characterise and evaluate nano-emulsions of ter-polymers of various compositions as eco-friendly binders for flexographic ink industry.

Abstract

Purpose

The purpose of this study is to prepare, characterise and evaluate nano-emulsions of ter-polymers of various compositions as eco-friendly binders for flexographic ink industry.

Design/methodology/approach

Various nano-emulsions of ter-polymers were prepared based on Vinyl acetate, Vinyl Versatate, butyl acrylate, acrylic acid and acrylamide monomers by means of a conventional seeded emulsion polymerisation technique, using K2S2O8 as the initiator. The characterisation of the prepared emulsions was performed using Fourier transform infrared, thermo-gravimetric analysis, gel permeation chromatography and transmission electron microscopy. A selection of co-polymers and ter-polymers were formulated with pigments and additional ingredients, as water-based flexographic inks. The inks were characterised for their rheological properties, pH, degree of dispersion, water-resistance and colour density.

Findings

It was found that the low viscosity of the prepared polymers may reduce the film thickness of the flexographic inks and may also increase the spreading of the ink on the surface. As a result, stable modified poly acrylate-based latex with improved physico-mechanical properties was obtained. The prepared latexes showed improved properties such as enhanced thermal stability and better water resistance. The effect of the emulsifier type on the properties of the resulting emulsion latexes and their corresponding films were investigated. Also, as the hydrophobic monomer increases, so does the colour density and increasing the binder ratio enhances the gloss values. The improving in gloss values were obtained and provide excellent adhesion properties for both the pigment particles and the base paper.

Research limitations/implications

The study focusses on the preparation of new water-based ter-polymer nano-particles and their use as eco-friendly binders for flexographic ink industry. Ink formulations based on other different type emulsion polymers could also be studied to assess the applicability of the ink formulation system found for other binders.

Practical implications

The ink formulations developed could find use in industrial-scale printing.

Originality/value

Eco-friendly environment and low-cost ink formulations for printing on paper substrates are novel.

Details

Pigment & Resin Technology, vol. 49 no. 6
Type: Research Article
ISSN: 0369-9420

Keywords

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