Search results

Streaming audio/video contents over the Internet requires large network bandwidth and timely delivery of media data. A streaming session is generally long and also needs a large I/O bandwidth at the streaming server. A streaming server, however, has limited network and I/O bandwidth. For this reason, a streaming server alone cannot scale a streaming service well. An entire audio/video media file often cannot be cached due to intellectual property right concerns of the content owners, security reasons, and also due to its large size. This makes a streaming service hard to scale using conventional proxy servers. Media file compression using variable‐bit‐rate (VBR) encoding is necessary to get constant quality video playback although it produces traffic bursts. Traffic bursts either waste network bandwidth or cause hiccups in the playback. Large network latency and jitter also cause long start‐up delay and unwanted pauses in the playback, respectively. In this paper, we propose a proxy based constant‐bit‐rate (CBR)‐transmission scheme for VBR‐encoded videos and a scalable streaming scheme that uses a CBRtransmission scheme to stream stored videos over the Internet. Our CBR‐streaming scheme allows a server to transmit a VBRencoded video at a constant bit rate, close to its mean encoding bit rate, and deals with the network latency and jitter issues efficiently in order to provide quick and hiccup free playback without caching an entire media file. Our scalable streaming scheme also allows many clients to share a server stream. We use prefix buffers at the proxy to cache the prefixes of popular videos, to minimize the start‐up delay and to enable near mean bit rate streaming from the server as well as from the proxy. We use smoothing buffers at the proxy not only to eliminate jitter and traffic burst effects but also to enable many clients to share the same server stream. We present simulation results to demonstrate the effectiveness of our streaming scheme.

This study aims to propose the adoption of artificial neural network (ANN)-based prediction intervals (PIs) to give more reliable prediction of labour productivity using historical data.

Using the proposed PI method, various sources of uncertainty affecting predictions can be accounted for, and a PI is proposed instead of a less reliable single-point estimate. The proposed PI consists of a lower and upper bound in which the realization of the predicted variable, namely, labour productivity, is anticipated to fall with a defined probability and represented in terms of a confidence level (CL).

The proposed PI method is implemented on a case study project to predict labour productivity. The quality of the generated PIs for the labour productivity is investigated at three confidence levels. The results show that the proposed method can predict the value of labour productivity efficiently.

This study is the first attempt in construction management to undertake a shift from deterministic point predictions to interval forecasts to improve the reliability of predictions. The proposed PI method will help project managers obtain accurate and credible predictions of labour productivity using historical data. With a better understanding of future outcomes, project managers can adopt appropriate improvement strategies to enhance labour productivity before commencing a project.

Point predictions provided by traditional deterministic ANN-based forecasting methodologies may be unreliable due to the different sources of uncertainty affecting predictions. The current study proposes ANN-based PIs as an alternative and robust tool to give a more reliable prediction of labour productivity using historical data. Using the proposed method, various sources of uncertainty affecting the predictions are accounted for, and a PI is proposed instead of a less reliable single point estimate.

The purpose of this paper is to examine the dynamical behavior of a combined three-story building with a 3D panel wall system including a soft story irregularity at the very first floor by doing a shaking table test. The upper two stories of the model were made out of the 3D panel system, while the first story was constructed only with moment-resisting RC frames.

Besides the experimental program, the numerical finite element method was implemented for the verification of the experimental results. In the experimental study, the building responses including the floors’ accelerations and drifts were considered, and the seismically vulnerable zones were reported and compared with that provided by the implemented FEM-based program.

After the shaking table test, the major cracks appeared at the end of each column and beam-column connections. Some negligible cracks were also visible around the beam-panel connections. However, no crack was seen in the upper stories. The lateral deformation of the studied building was investigated under the applied ELC25 and NGH135 earthquakes. Under the both aforementioned ground motion records, the first story drift was larger than two upper stories, since the moment-resisting frame was a soft story. The hysteretic relation between the shear and displacement for each story was studied. Under the applied ELC25 earthquake, the system remains linear and the stiffness of each story is obtainable as well.

This is the first time when the dynamical behavior of a combined system is studied and tested experimentally and numerically for data validation. Regarding the response of the assumed combined structure, the 3D panel system has a remarkable rigidity with respect to the conventional RC frames, also 3D panels have less weight than the moment-resisting frames.

The purpose of the paper is to back-test value-at-risk (VaR) models for conditional distributions belonging to a Generalized Hyperbolic (GH) family of Lévy processes – Variance Gamma, Normal Inverse Gaussian, Hyperbolic distribution and GH – and compare their risk-management features with a traditional unconditional extreme value (EV) approach using data from future contracts return data of S&P500, FTSE100, DAX, HangSeng and Nikkei 225 indices.

The authors apply tail-based and Lévy-based calibration to estimate the parameters of the models as part of the initial data analysis. While the authors utilize the peaks-over-threshold approach for generalized Pareto distribution, the conditional maximum likelihood method is followed in case of Lévy models. As the Lévy models do not have closed form expressions for VaR, the authors follow a bootstrap method to determine the VaR and the confidence intervals. Finally, for back-testing, they use both static calibration (on the entire data) and dynamic calibration (on a four-year rolling window) to test the unconditional, independence and conditional coverage hypotheses implemented with 95 and 99 per cent VaRs.

Both EV and Lévy models provide the authors with a conservative proportion of violation for VaR forecasts. A model targeting tail or fitting the entire distribution has little effect on either VaR calculation or a VaR model’s back-testing performance.

To the best of the authors’ knowledge, this is the first study to explore the back-testing performance of Lévy-based VaR models. The authors conduct various calibration and bootstrap techniques to test the unconditional, independence and conditional coverage hypotheses for the VaRs.

This paper reviews economic and finance research on Islamic investments. In the course of our review, we focus on the following issues: the performance of Islamic stock indexes, Islamic finance–growth nexus and Islamic real-estate investment trust market.

This literature survey consists of two stages such as random and systematic. It begins with a random search of articles with the intention to explore the three different areas of Islamic banking and finance. In order to maintain some level of quality of the literature review, we explored inside citations of articles based on relevant and recent articles from SCOPUS and Web of Science.

This paper represents an attempt to organise current research on Islamic stock markets, Islamic finance-growth nexus and Islamic real-estate finance: (1) the first prevailing finding is that Islamic stock indices are less volatile than conventional stock indices; (2) most empirical studies regarding Islamic finance–growth nexus focus on the impacts of banking sectors on growth and neglect other segments of the Islamic financial market; (3) based on our review of existing studies, there is no unanimous model for Islamic home financing in Islamic banks.

The mixed findings in this area hinder the understanding of Islamic investment and prevent identifying trends that support decision-making. Our review provides suggestions for prospective research directions. Most empirical studies regarding Islamic finance–growth nexus focus on the impacts of banking sectors on growth and neglect other segments of the Islamic financial market.

There is no literature review on Islamic finance-growth nexus and Islamic real-estate literature. Therefore, we are going to fill this gap to review these three different aspects of Islamic banking and finance.

Numerous finite elements are proposed based on analytical solutions. However, it is difficult to find the solutions for complicated governing equations. This paper aims to present a novel formulation in the framework of assumed stress quasi-conforming method for the static and free vibration analysis of anisotropic and symmetric laminated plates.

Firstly, an initial stress approximation ruled by 17 parameters, which satisfies the equilibrium equations is derived to improve the performance of the constructed element. Then the stress matrix is treated as the weighted function to weaken the strain-displacement equations. Finally, the Timoshenko’s laminated composite beam functions are adopted as boundary string-net functions for strain integration.

Several numerical examples are presented to show the performance of the new element, and the results obtained are compared with other available ones. Numerical results have proved that the new element is free from shear locking and possesses high accuracy for the analysis of anisotropic and symmetric laminated plates.

This paper proposes a new QC element for the static and free vibration analysis of anisotropic and symmetric laminated plates. In contrast with the complicated analytical solutions of the equilibrium equations, an initial stress approximation ruled by 17 parameters is adopted here. The Timoshenkos laminated composite beam functions are introduced as boundary string-net functions for strain integration. Numerical results demonstrate the new element is free from shear locking and possesses high accuracy for the analysis of anisotropic and symmetric laminated plates.

This study aims to understand the factors affecting the continuance usage intention (CUI) of mHealth among the rural elderly.

An integrated model was proposed with the constructs derived from multiple models such as the unified theory of acceptance and use of technology, information system success model and expectation confirmation model. Data were collected from 400 participants who had prior experiences with mHealth services in Bangladesh. The research model was tested using the partial least squares method based upon structural equation modelling.

The findings indicated that system quality, performance expectancy, facilitating conditions and social influence were significant to the degree of confirmation and ultimately affect satisfaction and CUI. Surprisingly, service quality and information quality were insignificant.

This study has added in the field of knowledge by contributing some new thoughts and interpretations of continuance usage modelling for mHealth services. The findings may become beneficial for the government agencies, policymakers, mHealth systems developers and service providers.

As limited research was found on CUI of mHealth in the integrated view of rural elderly’s value, this research contributes to the extant literature by categorizing key factors that might support to proliferate the continuance usage of this service. Moreover, the contextualization of the related variables and integration of the existing model is theoretically original. Furthermore, because of a generic approach, the findings could be easily modified to assist other developing countries in the planning and up-take of mHealth.

The countries that make up South Asia have young but rapidly aging populations. The purpose of this paper is to investigate some of the challenges that this rapid aging creates for societies and organizations in South Asia. It also points out how, properly managed, aging populations can create multiple opportunities for societies and organizations alike.

The paper uses secondary data about the aging situation globally. It pays special attention to the demographic situation in South Asian countries and uses as examples policies dealing with aging populations in other countries that have gone through demographic transitions in the recent past.

Aging populations are bringing about numerous challenges in the region, including rising costs for pensions and healthcare, higher dependency ratios, and changing family dynamics. South Asia will enjoy a one-time demographic dividend. Policy makers and managers need to put the right policies in place to ensure that they take maximum advantage of this opportunity.

The study is based on secondary data. It is a perspectives piece and does not provide an in-depth study of the specific issues raised.

The study details how organizations can best manage this transition. This includes planning for a multigenerational workforce, providing accommodations for older workers, and fostering mentoring, knowledge transfer, cross-training and mixed-age work teams.

This study analyzes some of the social issues that arise because of aging populations, such as the challenge of creating pension and healthcare systems, dealing with a rising old age dependency ratio, and dealing with a gradual transition to single-family households.

This is one of the first studies that look at the coming demographic transition in South Asia, and details some of the challenges and opportunities that arise both in terms of policies and managerial implications.

The purpose of this paper is to examine the connectedness across a variety of Sukuk and conventional bond indices and the implications for optimal asset allocation for the period January 1, 2010–April 30, 2020.

The data set consists of five major Sukuk (Dow Jones Sukuk, Thompson Reuters BPA Malaysia Sukuk, Indonesia Government Sukuk, S&P MENA Sukuk and Tadawul Sukuk and Bonds Index) and five conventional bond indexes, one for developed (USA) and four for emerging markets (Malaysia, Indonesia, Africa and Qatar). This study investigates the connectedness and volatility spillover effects across the aforementioned indices, by following the Diebold and Yilmaz (2012) approach, based on the time-varying parameter vector autoregressive (TVP-VAR) model. In addition, this paper provides optimal hedge ratios and portfolio weights for investors.

The empirical results show that Sukuk and conventional bond markets are highly integrated and that total connectedness exhibits sensitivity to exogenous shocks. The Dow Jones and the Malaysian Sukuk indices are the primary shock transmitters to other markets. However, the weak volatility spillovers between the Dow Jones and conventional bonds suggest that opportunities for optimal asset allocation may in fact exist. The highest (lowest) hedging effectiveness can be achieved by taking a short position in Malaysian (Qatarian) bonds.

To the best of the knowledge, this is the largest sample taken into account to investigate the connectedness between Sukuk and conventional bonds.