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1 – 10 of over 3000
Article
Publication date: 13 August 2019

Mohamed El-Beltagy

The paper aims to compare and clarify the differences and between the two well-known decomposition spectral techniques; the Winer–Chaos expansion (WCE) and the Winer–Hermite…

Abstract

Purpose

The paper aims to compare and clarify the differences and between the two well-known decomposition spectral techniques; the Winer–Chaos expansion (WCE) and the Winer–Hermite expansion (WHE). The details of the two decompositions are outlined. The difficulties arise when using the two techniques are also mentioned along with the convergence orders. The reader can also find a collection of references to understand the two decompositions with their origins. The geometrical Brownian motion is considered as an example for an important process with exact solution for the sake of comparison. The two decompositions are found practical in analysing the SDEs. The WCE is, in general, simpler, while WHE is more efficient as it is the limit of WCE when using infinite number of random variables. The Burgers turbulence is considered as a nonlinear example and WHE is shown to be more efficient in detecting the turbulence. In general, WHE is more efficient especially in case of nonlinear and/or non-Gaussian processes.

Design/methodology/approach

The paper outlined the technical and literature review of the WCE and WHE techniques. Linear and nonlinear processes are compared to outline the comparison along with the convergence of both techniques.

Findings

The paper shows that both decompositions are practical in solving the stochastic differential equations. The WCE is found simpler and WHE is the limit when using infinite number of random variables in WCE. The WHE is more efficient especially in case of nonlinear problems.

Research limitations/implications

Applicable for SDEs with square integrable processes and coefficients satisfying Lipschitz conditions.

Originality/value

This paper fulfils a comparison required by the researchers in the stochastic analysis area. It also introduces a simple efficient technique to model the flow turbulence in the physical domain.

Details

Engineering Computations, vol. 36 no. 7
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 1 June 1997

H. Holden

Ball grid arrays, chip‐sized grid arrays, directchip attach and flip chip are packages which are increasingly penetrating the market. However,the challenge to PCB fabricators will…

209

Abstract

Ball grid arrays, chip‐sized grid arrays, direct chip attach and flip chip are packages which are increasingly penetrating the market. However, the challenge to PCB fabricators will be how to meet the need imposed by these packages in terms of increased circuit density. Shrinking traces and spaces certainly offer some relief, but traces below 3 mils on 2 mil core will not meet the signal integrity requirements of high speed logic. The real opportunity to increase density is the reduction of via diameters and the adoption of alternative via structures. Non‐drilled vias offer the newest opportunity to increase board density while also reducing costs and board thickness. This paper looks at twelve ‘build‐up technologies’ that all employ non‐drilled vias as well as buried and blind vias. The design rules, materials, manufacturing process, structures, reliability and applications of many of these will be examined and compared. Highlighted will be the application to PCMCIA card (PC card) design and fabrication. Finally, preliminary cost comparisons will be given in order to position these technologies against standard PCBs.

Details

Circuit World, vol. 23 no. 2
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 26 August 2014

Mourad Mroua and Fathi Abid

Since equity markets have a dynamic nature, the purpose of this paper is to investigate the performance of a revision procedure for domestic and international portfolios, and…

2162

Abstract

Purpose

Since equity markets have a dynamic nature, the purpose of this paper is to investigate the performance of a revision procedure for domestic and international portfolios, and provides an empirical selection strategy for optimal diversification from an American investor's point of view. This paper considers the impact of estimation errors on the optimization processes in financial portfolios.

Design/methodology/approach

This paper introduces the concept of portfolio resampling using Monte Carlo method. Statistical inferences methodology is applied to construct the sample acceptance regions and confidence regions for the resampled portfolios needing revision. Tracking error variance minimization (TEVM) problem is used to define the tracking error efficient frontiers (TEEF) referring to Roll (1992). This paper employs a computation method of the periodical after revision return performance level of the dynamic diversification strategies considering the transaction cost.

Findings

The main finding is that the global portfolio diversification benefits exist for the domestic investors, in both the mean-variance and tracking error analysis. Through TEEF, the dynamic analysis indicates that domestic dynamic diversification outperforms international major and emerging diversification strategies. Portfolio revision appears to be of no systematic benefit. Depending on the revision of the weights of the assets in the portfolio and the transaction costs, the revision policy can negatively affect the performance of an investment strategy. Considering the transaction costs of portfolios revision, the results of the return performance computation suggest the dominance of the global and the international emerging markets diversification over all other strategies. Finally, an assessment between the return and the cost of the portfolios revision strategy is necessary.

Originality/value

The innovation of this paper is to introduce a new concept of the dynamic portfolio management by considering the transaction costs. This paper investigates the performance of a revision procedure for domestic and international portfolios and provides an empirical selection strategy for optimal diversification. The originality of the idea consists on the application of a new statistical inferences methodology to define portfolios needing revision and the use of the TEVM algorithm to define the tracking error dynamic efficient frontiers.

Details

International Journal of Managerial Finance, vol. 10 no. 4
Type: Research Article
ISSN: 1743-9132

Keywords

Book part
Publication date: 20 September 2018

Pravin Chopade, Michael Yudelson, Benjamin Deonovic and Alina A. von Davier

This chapter focuses on the state-of-the-art modeling approaches used in Intelligent Tutoring Systems (ITSs) and the frameworks for researching and operationalizing individual and…

Abstract

This chapter focuses on the state-of-the-art modeling approaches used in Intelligent Tutoring Systems (ITSs) and the frameworks for researching and operationalizing individual and group models of performance, knowledge, and interaction. We adapt several ITS methodologies to model team performance as well as individuals’ performance of the team members. We briefly describe the point processes proposed by von Davier and Halpin (2013), and we also introduce the Competency Architecture for Learning in teaMs (CALM) framework, an extension of the Generalized Intelligent Framework for Tutoring (GIFT) (Sottilare, Brawner, Goldberg, & Holden, 2012) to be used for team settings.

Book part
Publication date: 28 September 2015

Arief Rahman

Citizens are substantial stakeholders in every e-government system, thus their willingness to use and ability to access the system are critical. Unequal access and information and…

Abstract

Citizens are substantial stakeholders in every e-government system, thus their willingness to use and ability to access the system are critical. Unequal access and information and communication technology usage, which is known as digital divide, however has been identified as one of the major obstacles to the implementation of e-government system. As digital divide inhibits citizen’s acceptance to e-government, it should be overcome despite the lack of deep theoretical understanding on this issue. This research aimed to investigate the digital divide and its direct impact on e-government system success of local governments in Indonesia as well as indirect impact through the mediation role of trust. In order to get a comprehensive understanding of digital divide, this study introduced a new type of digital divide, the innovativeness divide.

The research problems were approached by applying two-stage sequential mixed method research approach comprising of both qualitative and quantitative studies. In the first phase, an initial research model was proposed based on a literature review. Semi-structured interview with 12 users of e-government systems was then conducted to explore and enhance this initial research model. Data collected in this phase were analyzed with a two-stage content analysis approach and the initial model was then amended based on the findings. As a result, a comprehensive research model with 16 hypotheses was proposed for examination in the second phase.

In the second phase, quantitative method was applied. A questionnaire was developed based on findings in the first phase. A pilot study was conducted to refine the questionnaire, which was then distributed in a national survey resulting in 237 useable responses. Data collected in this phase were analyzed using Partial Least Square based Structural Equation Modeling.

The results of quantitative analysis confirmed 13 hypotheses. All direct influences of the variables of digital divide on e-government system success were supported. The mediating effects of trust in e-government in the relationship between capability divide and e-government system success as well as in the relationship between innovativeness divide and e-government system success were supported, but was rejected in the relationship between access divide and e-government system success. Furthermore, the results supported the moderating effects of demographic variables of age, residential place, and education.

This research has both theoretical and practical contributions. The study contributes to the developments of literature on digital divide and e-government by providing a more comprehensive framework, and also to the implementation of e-government by local governments and the improvement of e-government Readiness Index of Indonesia.

Details

E-Services Adoption: Processes by Firms in Developing Nations
Type: Book
ISBN: 978-1-78560-325-9

Keywords

Open Access
Article
Publication date: 7 April 2023

Eva Seewald, Samantha Baerthel and Trung Thanh Nguyen

This study aims to investigate whether the participation in land rental markets helps to mitigate impacts by climate change on multidimensional poverty in Thailand and Vietnam.

Abstract

Purpose

This study aims to investigate whether the participation in land rental markets helps to mitigate impacts by climate change on multidimensional poverty in Thailand and Vietnam.

Design/methodology/approach

The authors use precipitation data from the National Aeronautics and Space Administration (NASA) and self-reported shocks from the Thailand Vietnam Socio-Economic Panel (TVSEP) project to estimate climate change. Data from the TVSEP are also used to calculate a multidimensional poverty index (MPI). Fixed-effect logit panel regressions with interaction terms are implemented to analyze the above mentioned.

Findings

The results show that land rental markets are used as mitigation strategies to climate change in Thailand and Vietnam. The participation in land rental markets also reduces multidimensional poverty. However, as a mitigation strategy, land rental markets are only successful in certain circumstances.

Research limitations/implications

The results show that there is potential in using land rental markets as mitigation strategies to climate change. Further research is needed to better understand which adaptation strategies, besides land rental market participation, and which combinations of different adaptation strategies are successful to mitigate negative effects induced by climate change.

Practical implications

The results show that there is potential in using land rental markets as mitigation strategies to climate change. Therefore, education in the participation in land rental markets and how to use them as a mitigation strategy can be a way to increase households' resilience to negative effects induced by climate change. Households make better decisions regarding their land when they are better informed on the functionality of land rental markets. Additionally, being better informed increases self-confidence to participate in land-rental markets.

Originality/value

Land rental markets as a mitigation strategy to climate change rarely have been studied, and if so, mainly the effect of leasing land has been studied. Additionally, the authors implement new measures of poverty – a multidimensional view on poverty which provides new insights into who are the poor and how they can be lift out of poverty.

Details

Journal of Economics and Development, vol. 25 no. 2
Type: Research Article
ISSN: 1859-0020

Keywords

Book part
Publication date: 20 September 2018

Stephen B. Gilbert, Michael C. Dorneich, Jamiahus Walton and Eliot Winer

This chapter describes five disciplinary domains of research or lenses that contribute to the design of a team tutor. We focus on four significant challenges in developing…

Abstract

This chapter describes five disciplinary domains of research or lenses that contribute to the design of a team tutor. We focus on four significant challenges in developing Intelligent Team Tutoring Systems (ITTSs), and explore how the five lenses can offer guidance for these challenges. The four challenges arise in the design of team member interactions, performance metrics and skill development, feedback, and tutor authoring. The five lenses or research domains that we apply to these four challenges are Tutor Engineering, Learning Sciences, Science of Teams, Data Analyst, and Human–Computer Interaction. This matrix of applications from each perspective offers a framework to guide designers in creating ITTSs.

Details

Building Intelligent Tutoring Systems for Teams
Type: Book
ISBN: 978-1-78754-474-1

Keywords

Book part
Publication date: 28 September 2023

Peterson K. Ozili

The chapter evaluates how the demise of cryptocurrencies as a medium of exchange may result from the issue of digital money by central banks. To evaluate the likelihood that…

Abstract

The chapter evaluates how the demise of cryptocurrencies as a medium of exchange may result from the issue of digital money by central banks. To evaluate the likelihood that central bank digital money would cause the demise of cryptocurrencies, the research employs discourse analysis and literature review. In this chapter, I demonstrate how the issuing of a digital currency by a central bank might result in the demise of private digital currencies like bitcoin. I contend that central banks will make use of their monetary authority and the confidence that people have in currency guaranteed by the government. This might provide considerable motivation for central banks to launch their own digital money. The creation of a digital currency by a central bank has the potential to reduce confidence in cryptocurrencies, which might eventually cause them to collapse. The chapter is the first to argue that fiat digital money should prevail over private digital currency.

Article
Publication date: 5 September 2008

Ma Lei Hsieh and Hugh Holden

This paper aims to report on a study of an academic library's wireless laptop lending service. The authors believed that the unexpectedly low usage level of the Monmouth…

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Abstract

Purpose

This paper aims to report on a study of an academic library's wireless laptop lending service. The authors believed that the unexpectedly low usage level of the Monmouth University Library's Laptop Lending Service (LLS) could best be understood by engaging the intended users of the LLS, that is, the students of Monmouth University, a small university in New Jersey. A formal, systematic survey would provide substantive data that would help the Library to evaluate this service and determine how well it meets the needs and expectations of students and answer the question, “Is it sufficient to provide wireless access?”

Design/methodology/approach

The open source application PHP Surveyor was used to construct two web‐based surveys which were conducted two years apart (2005 and 2007). An invitation to participate in the survey was emailed to all registered students. Follow‐up emails attended both surveys.

Findings

Among other things, it was learned that the fact that a large majority of the students believe that an LLS is a valuable service may not, in itself, assure a high level of usage. But also, a high level of personal laptop ownership among students does not necessarily lead to low demand for the service.

Practical implications

The useful information and ideas that we gained from these surveys could benefit libraries that are planning to implement laptop services, or wish to assess their existing services.

Originality/value

Few research studies on library laptop services have focused on the students' perspective. This study does that, but also, uniquely, made it possible to juxtapose results from various similar studies of students and a survey of academic librarians.

Details

Library Hi Tech, vol. 26 no. 3
Type: Research Article
ISSN: 0737-8831

Keywords

Article
Publication date: 6 November 2017

Kaleb Shiferaw, Berhanu Gebremedhin and Dereje Legesse Zewdie

The purpose of this paper is to explore the factors that affect farmer’s decision to allocate credit for livestock production. The results are expected to contribute to the…

Abstract

Purpose

The purpose of this paper is to explore the factors that affect farmer’s decision to allocate credit for livestock production. The results are expected to contribute to the understanding of what motivates smallholders to allocate credit to agricultural production in general and livestock production in particular. A better understanding of the farmers’ behavior in allocating credit for livestock would provide useful information for project implementers and financial institutions that work with small-scale livestock producers.

Design/methodology/approach

A cross-section data set collected in 2014 from 5,000 households and 497 rural communities in the major highland regions of Ethiopia is examined. The authors developed a conceptual framework for credit allocation decision. Percentiles, means, and standard deviation as well as t, χ2 and Fisher’s exact tests for association and Cramer’s V measure for strength of association have been used to describe the status of farmer’s access to credit and analyze credit utilization, while a three-stage probit model with double sample selection is used to identify factors that affect household’s decision to allocate credit for livestock production.

Findings

After controlling for potential selection biases, sex and literacy status of household head, land size, wealth and access to livestock centered extension service are found to have a statistically significant effect on farmers’ decision to allocate credit to livestock production. The results showed female-headed households, wealthy farmers, farmers with small plot of land and farmers that have access to livestock centered extension services are more likely to allocate the credit for livestock production. The results suggest that policies aimed at improving access to credit together with access to livestock focused extension service are more effective in increasing livestock production.

Research limitations/implications

The study’s findings should be viewed with perspective and caution, as only households with excess demand for credit were the subject of the research.

Originality/value

The contribution of this paper is twofold. First, it is one of a very few empirical studies that try to identify factors that affect households credit allocation to livestock in systematic way that removed confounding effects using three-stage probit models. Given the emphasis on financial constraints in livestock development, new empirical insights on household credit allocation are essential to better inform development interventions. Second, the analysis relies on a comprehensive data set that represents the major agricultural system of the country.

Details

Agricultural Finance Review, vol. 77 no. 4
Type: Research Article
ISSN: 0002-1466

Keywords

1 – 10 of over 3000