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Open Access
Article
Publication date: 22 October 2021

Syed Farid Uddin, Ayan Alam Khan, Mohd Wajid, Mahima Singh and Faisal Alam

The purpose of this paper is to show a comparative study of different direction-of-arrival (DOA) estimation techniques, namely, multiple signal classification (MUSIC) algorithm…

1353

Abstract

Purpose

The purpose of this paper is to show a comparative study of different direction-of-arrival (DOA) estimation techniques, namely, multiple signal classification (MUSIC) algorithm, delay-and-sum (DAS) beamforming, support vector regression (SVR), multivariate linear regression (MLR) and multivariate curvilinear regression (MCR).

Design/methodology/approach

The relative delay between the microphone signals is the key attribute for the implementation of any of these techniques. The machine-learning models SVR, MLR and MCR have been trained using correlation coefficient as the feature set. However, MUSIC uses noise subspace of the covariance-matrix of the signals recorded with the microphone, whereas DAS uses the constructive and destructive interference of the microphone signals.

Findings

Variations in root mean square angular error (RMSAE) values are plotted using different DOA estimation techniques at different signal-to-noise-ratio (SNR) values as 10, 14, 18, 22 and 26dB. The RMSAE curve for DAS seems to be smooth as compared to PR1, PR2 and RR but it shows a relatively higher RMSAE at higher SNR. As compared to (DAS, PR1, PR2 and RR), SVR has the lowest RMSAE such that the graph is more suppressed towards the bottom.

Originality/value

DAS has a smooth curve but has higher RMSAE at higher SNR values. All the techniques show a higher RMSAE at the end-fire, i.e. angles near 90°, but comparatively, MUSIC has the lowest RMSAE near the end-fire, supporting the claim that MUSIC outperforms all other algorithms considered.

Open Access
Article
Publication date: 3 May 2021

Habeeba Khan, Sayyed Arif Ali, Mohd Wajid and Muhammad Shah Alam

In this work, a microstrip antenna array for wireless power transfer (WPT) application is reported. The proposed 4 × 4 antenna array operating at 16 GHz is designed using a…

2725

Abstract

Purpose

In this work, a microstrip antenna array for wireless power transfer (WPT) application is reported. The proposed 4 × 4 antenna array operating at 16 GHz is designed using a flexible Kapton polyimide substrate for a far-field charging unit (FFCU).

Design/methodology/approach

The proposed antenna is designed using the transmission line model on a flexible Kapton polyimide substrate. The finite element method (FEM) is used to perform the full-wave electromagnetic analysis of the proposed design.

Findings

The antenna offers −10 dB bandwidth of 240 MHz with beam width and broadside gain found to be 29.4° and 16.38 dB, respectively. Also, a very low cross-polarization level of −34.23 dB is achieved with a radiation efficiency of 36.67%. The array is capable of scanning −15° to +15° in both the elevation and azimuth planes.

Originality/value

The radiation characteristics achieved suggest that the flexible substrate antenna is suitable for wireless charging purposes.

Details

Frontiers in Engineering and Built Environment, vol. 1 no. 1
Type: Research Article
ISSN: 2634-2499

Keywords

Article
Publication date: 22 August 2023

Xian Yun Tan, Norhayati Mahyuddin, Syahrul Nizam Kamaruzzaman, Norhayati Mat Wajid and Abdul Murad Zainal Abidin

Commercial buildings, which include office buildings, are one of the three major energy-consuming sectors, alongside industrial and transportation sectors. The vast increase in…

Abstract

Purpose

Commercial buildings, which include office buildings, are one of the three major energy-consuming sectors, alongside industrial and transportation sectors. The vast increase in the number of buildings is a positive sign of the rapid development of Malaysia. However, most Malaysian government office buildings tend to consume energy inefficiently due to lack of energy optimization. Most of the previous studies focused on the performance of green buildings in fulfilling the green development guidelines. As such, it is essential to study the energy performance of existing government office buildings that were constructed before most energy-efficient standards were implemented to mitigate energy wastage due to the lack of energy optimization. This study aims to analyse the energy performance of existing non-green Malaysian government office buildings and the factors that influence building energy consumption, as well as to evaluate the efficacy of the existing energy conservation measures.

Design/methodology/approach

This study was conducted by a literature review and case study. The chosen buildings are six government office building blocks located in Kuala Lumpur, the capital city of Malaysia. In this study, a literature review has been conducted on the common factors affecting energy consumption in office buildings. The energy consumption data of the buildings were collected to calculate the building energy intensity (BEI). The BEI was compared to the MS1525:2019 and GBI benchmarks to evaluate energy performance. SketchUp software was utilized to illustrate the solar radiation and sun path diagram of the case study buildings. Finally, recommendations were derived for retrofit strategies based on non-design factors and passive design factors.

Findings

In typical government office buildings, the air-conditioning system consumed the most energy at 65.5%, followed by lighting system at 22.6%, and the remaining 11.9% was contributed by office appliances. The energy performance of the case study buildings is considered as satisfactory as the BEI did not exceed the MS1525:2019 benchmark of 200 kWh/m2/year. The E Block recorded the highest BEI of 183.12 kWh/m2/year in 2020 due to its north-east orientation which is exposed to the most solar radiation. Besides, E Block consists of rooms that can accommodate large number of occupants. As such, non-design factors which include higher occupancy rate and higher cooling demand due to high outdoor temperature leads to higher energy consumption. By considering passive design features such as building orientation and building envelope thermal properties, energy consumption can be reduced significantly.

Originality/value

This study provided a comprehensive insight into the energy performance of Malaysian government office buildings, which were constructed before the energy-efficient standards being introduced. By calculating the BEI of six government office buildings, it is found that the energy performance of the case study buildings fulfils the MS1525 benchmark, and that all their BEIs are below 200 kWh/m2/year. Malaysia's hot and humid climate significantly affects a building's cooling load, and it is found the air-conditioning system is the major energy consumer of Malaysian government office buildings. This study discusses the efficacy of the energy-saving measures implemented in the case study buildings to optimize energy consumption. Recommendations were derived based on the non-design factors and passive design factors that affected the energy consumption of the case study building. It is envisioned that this study can provide practical strategies for retrofit interventions to reduce energy consumption in Malaysian office buildings as well as for office buildings that are in a similar climate.

Details

Open House International, vol. 49 no. 3
Type: Research Article
ISSN: 0168-2601

Keywords

Article
Publication date: 1 December 2022

Muhammad Wajid Raza, Bahrawar Said and Ahmed Elshahat

This study aims to provide a comparative insight into the level of informational efficiency and irregularities of Shariah-compliant stocks and conventional stocks in three…

204

Abstract

Purpose

This study aims to provide a comparative insight into the level of informational efficiency and irregularities of Shariah-compliant stocks and conventional stocks in three emerging markets, namely, China, Malaysia and Pakistan. The empirical evidence is provided for pre-crisis and crisis periods caused by the Covid-19 pandemic.

Design/methodology/approach

Informational efficiency is measured using the variance ratio (VR) Test developed by Kim (2006). The Approximate Entropy (ApEn) Metrics is used to investigate the level of irregularities in stock prices caused by the pandemic.

Findings

All the three emerging markets in the sample are not immune to the crisis caused by Covid-19 pandemic. The level of informational efficiency of both the Shariah-compliant and conventional stock is affected by the crisis. However, the former exhibits relatively high level of informational efficiency and stability in returns as compared to more volatility of conventional stocks.

Practical implications

This study provides market agents and policy makers with a robust assessment of the impact of the Covid-19 pandemic on informational efficiency of Shariah-compliant and conventional stocks. Relatively high informational efficiency of Shariah-compliant stocks indicates that they are more transparent and that investors can trust the Shariah-compliant stocks more. This higher level of transparency and trust leads to more steady returns and lower levels of risk even during turbulent time like Covid-19. Investors can gain superior returns by conducting fundamental analysis and investing in index funds.

Originality/value

To the best of the authors’ knowledge, this is the first study that highlights the difference in informational efficiency of conventional stocks and Shariah-compliant stocks in the crisis period caused by Covid-19. Unlike previous studies, this study uses firm level data which enables firm-wise assessment of informational efficiency.

Details

International Journal of Islamic and Middle Eastern Finance and Management, vol. 16 no. 3
Type: Research Article
ISSN: 1753-8394

Keywords

Open Access
Article
Publication date: 19 January 2024

Ummi Ibrahim Atah, Mustafa Omar Mohammed, Abideen Adewale Adeyemi and Engku Rabiah Adawiah

The purpose of this paper is to propose a model that will demonstrate how the integration of Salam (exclusive agricultural commodity trade) with Takaful (micro-Takaful – a…

Abstract

Purpose

The purpose of this paper is to propose a model that will demonstrate how the integration of Salam (exclusive agricultural commodity trade) with Takaful (micro-Takaful – a subdivision of Islamic insurance) and value chain can address major challenges facing the agricultural sector in Kano State, Nigeria.

Design/methodology/approach

The study conducted a thorough and critical analysis of relevant literature and existing models of financing agriculture in Nigeria to come up with the proposed model.

Findings

The findings indicate that measures undertaken to address the major challenges fail. In view of this, this study proposed Bay-Salam with Takaful and value chain model to solve a number of challenges such as poor access to financing, poor marketing and pricing, delay, collateral requirement and risk issues in order to avail farmers with easy access to finance and provide effective security to financial institutions.

Research limitations/implications

The paper is limited to using secondary data. Therefore, empirical investigation can be carried out to strengthen the validation of the model.

Practical implications

The study outcome seeks to improve the productivity of the farmers through enhancing their access to finance. This will increase their level of production and provide more employment opportunities. In addition, it will boost financial inclusion, income generation, poverty alleviation, standard of living, food security and overall economic growth and development.

Originality/value

The novelty of this study lies in the integration of classical Bay-Salam with Takaful and value chain and create a unique model structure which the researchers do not come across in any research that presented it in Nigeria.

Details

Islamic Economic Studies, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1319-1616

Keywords

Open Access
Article
Publication date: 27 July 2023

Mohd Abass Bhat, Shagufta Tariq and Riyaz Ahmad Rainayee

In the purview of stress–turnover relationship, the present study aims to explore the endogenous and exogenous aspects of stress and employees' turnover intentions. Further, it…

2043

Abstract

Purpose

In the purview of stress–turnover relationship, the present study aims to explore the endogenous and exogenous aspects of stress and employees' turnover intentions. Further, it also intends to evaluate the mediating role of perceived employee's exploitation between stressors and employee turnover intentions. For that matter, antecedents of stressors were identified and classified into endogenous and exogenous stressors: endogenous stressors relate to the employees' negative psychological contact within an organization and exogenous stressors are various macro-economic factors which have a considerable influence on employees' workplace behavior.

Design/methodology/approach

For the purpose of this study, this study choses private school teachers as respondents working in the economically depressed state of India. Thus, data for the present study has been collected from 628 private school teachers of J&K (India) which were randomly selected. In order to ensure valid and reliable statistical inferences from the study, data collected has been validated using confirmatory factor analysis and hypothesis testing has been carried out through structural equation modeling.

Findings

It was found that both types of stressors were contributing negatively toward employee's psychological state resulting in undesirable employee organizational relationships manifested as turnover intentions among employees. Moreover, perceived employee's exploitation was found to intensify the relationship of employee turnover as a dependent variable regressed on endogenous, exogenous and occupational stress by fully mediating the stress–turnover intricacies.

Research limitations/implications

The implications of the study include the identification of employees' stressor needs in order to gauge the understanding of the mechanism by which employees react to their environment and develop attitudes toward their jobs. The present study includes a small sample size obtained from private educational institutions only. Therefore, there is a need to take a geographically diverse sample that is inevitable for universal inferences and validity.

Originality/value

Very little research has been conducted to explore endogenous, exogenous and unique stressors such as economic stress and perceived external opportunities which constitute the overall stress. Moreover, to the best of the authors’ knowledge, this is the first study which tests the model empirically that examines the effect of stress–turnover relationship through perceived employee's exploitation in the teaching and educational sector.

Details

PSU Research Review, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2399-1747

Keywords

Article
Publication date: 25 May 2023

Mohamed Aboelmaged, Shaker Bani-Melhem, Mohd Ahmad Al-Hawari and Imran Ali

Literature on product innovation (PI) has witnessed tremendous growth over the past 60 years. Yet, there has been a dearth of a comprehensive review of the extant PI research…

Abstract

Purpose

Literature on product innovation (PI) has witnessed tremendous growth over the past 60 years. Yet, there has been a dearth of a comprehensive review of the extant PI research maintaining the breadth and depth of the topic. To seal this gap, this paper aims to explore the intellectual foundations and emergent trends in 2,588 research papers on PI from 1962 to 2022.

Design/methodology/approach

The paper adopts a bibliometric analysis approach via visualization maps of prolific contributions, co-citation, co-occurrence and thematic networks.

Findings

Emerging streams, frontiers and hotspots in PI research are revealed and a knowledge graph is developed. The review provides a broad spectrum of opportunities that enrich imminent research to better inform business decisions.

Practical implications

The review addresses 20 research questions associated with barely examined areas in PI research that require further analysis in imminent research.

Originality/value

To the best of the authors' knowledge, this is the first review that comprehensively synthesizes the intersected knowledge base of PI research using bibliometric analysis of a vast number of documents within a long time span.

Details

Benchmarking: An International Journal, vol. 31 no. 6
Type: Research Article
ISSN: 1463-5771

Keywords

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