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Article
Publication date: 5 July 2021

Swetha K., P.V.Y. Jayasree and Vijay Saradhi

The purpose of this paper is to provide a miniaturized antenna design for a mobile phone. The second design is 2 × 4 elements multiple-input multiple-output (MIMO) antenna with 8…

154

Abstract

Purpose

The purpose of this paper is to provide a miniaturized antenna design for a mobile phone. The second design is 2 × 4 elements multiple-input multiple-output (MIMO) antenna with 8 port having a substrate size is 20 × 40 mm2 which fits easier within smartphone handset devices for fifth generation technology.

Design/methodology/approach

In this work, the first design is a conventional patch antenna, and its dual-band characteristics are obtained by characteristic mode analysis. In this method, orthogonal modes are carried out for 28 GHz and 38 GHz, and further, both orthogonal modes are excited by finite integration technique full-wave method with 50 Ohm single port coaxial feed line.

Findings

In this configuration, better return loss, high gain, larger bandwidths and low envelope correlation coefficient (ECC) are evaluated by the full-wave simulation computer simulation technology (CST) studio suite.

Originality/value

In this arrangement, the performance metrics of the antenna are analyzed using electromagnetic simulator CST Studio suite.

Details

Circuit World, vol. 47 no. 3
Type: Research Article
ISSN: 0305-6120

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Article
Publication date: 16 July 2021

Khader Zelani Shaik, Siddaiah P. and K. Satya Prasad

Millimeter wave spectrum represents new opportunities to add capacity and faster speeds for next-generation services as fifth generation (5G) applications. In its Spectrum…

105

Abstract

Purpose

Millimeter wave spectrum represents new opportunities to add capacity and faster speeds for next-generation services as fifth generation (5G) applications. In its Spectrum Frontiers proceeding, the Federal Communications Commision decided to focus on spectrum bands where the most spectrums are potentially available. A low profile antenna array with new decoupling structure is proposed and expected to resonate at higher frequency bands, i.e. millimeter wave frequencies, which are suitable for 5G applications.

Design/methodology/approach

The presented antenna contains artificial magnetic conductor (AMC) surface as decoupling structure. The proposed antenna array with novel AMC surface is operating at 29.1GHz and proven to be decoupling structure and capable of enhancing the isolation by reducing mutual coupling as 8.7dB between the array elements. It is evident that, and overall gain is improved as 10.1% by incorporating 1x2 Array with AMC Method. Mutual coupling between the elements of 1 × 2 antenna array is decreased by 39.12%.

Findings

The proposed structure is designed and simulated using HFSS software and the results are obtained in terms of return loss, gain, voltage standing wave ratio (VSWR) and mutual coupling. The S-Parameters of each stage of design is tabulated and compared with each other to prove the decoupling capability of AMC surface in antenna arrays.

Originality/value

The proposed structure is designed and simulated using HFSS software, and the results are obtained in terms of return loss, gain, VSWR and mutual coupling. The S-Parameters of each stage of design is tabulated and compared with each other to prove the decoupling capability of AMC surface in antenna arrays.

Details

Circuit World, vol. 47 no. 3
Type: Research Article
ISSN: 0305-6120

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Article
Publication date: 10 June 2021

Srinu Budumuru and Satya Anuradha Mosa

Fiber-reinforced polymers (FRP) contain critical electrical conductivity for high-intensity radiated fields such as lightning strike susceptibility, electromagnetic energy from…

134

Abstract

Purpose

Fiber-reinforced polymers (FRP) contain critical electrical conductivity for high-intensity radiated fields such as lightning strike susceptibility, electromagnetic energy from radar, airborne radio frequency transmitter. To provide high-intensity radiated field protection (HIRFP) for the electric and electronic aircraft system and defied the EMI effect on it, metal matrix composite was conquered. To provide the dynamic ever-increasing requirement of industries, it is necessary that Al6061 metal matrix composite assisted with AL2O3 and fly ash is used to construct the aircraft to provide HIRFP. The thickness of the material can be maintained as low as possible to use it as a coating material for the aircraft surface. X-band for oblique incidence is used to measure electromagnetic and mechanical safeguarding properties of composites.

Design/methodology/approach

Day by day, the applications of aerospace are becoming digital and automated. Proper shielding techniques are required to operate digital electronic devices without electromagnetic interference. It leads to a rapid rise in temperature, thermal ablation, delamination, and adverse effects on the electric and electronic aircraft system. Fly ash, a metal matrix material composite AL6061 with different percentages of reinforcement of Al2O3, was contemplated and experimented with for mechanical properties like tensile strength, density and hardness.

Findings

The obtained results compared with adjusted values and an improvement of 0.19, 0.18, 0.14 g/cm3 for density of MMC-1, MMC-2, MMC-3.31, 11 MPa for tensile strength of MMC-1, MMC-2. 24, 27, 23 BHN for hardness of MMC-1, MMC-2, MMC-3. With regard to the shielding effectiveness the results compared with adjusted values and obtained 11.36, 14.56, 19.47 dB better value than it. According to the above results, fabricated MMC’s provide superior results for a defined application like HIRFP(Surface material of aircraft).

Practical implications

It can be used to protect electronic devices under a high-intensity radiated field, mainly in aircraft design to protect from lightning effect.

Originality/value

For a better approximation of the signal toward the practical case, the oblique incidence was considered with a different combination of Al2O3 and fly ash, reinforced to pure AL6061 to get better shielding and mechanical properties.

Details

International Journal of Intelligent Computing and Cybernetics, vol. 14 no. 3
Type: Research Article
ISSN: 1756-378X

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Article
Publication date: 3 July 2017

Anan Zhang, Fan Zhang, Zhi Li, Qian Li, Xuliang Zhang and Jing Wang

With the growing scale of power grids, integrated power grids often contain multiple areas. When the control centre of each regional grid conducts an assessment of local voltage…

107

Abstract

Purpose

With the growing scale of power grids, integrated power grids often contain multiple areas. When the control centre of each regional grid conducts an assessment of local voltage stability, the calculation is always based on the local regional power grid model. However, less consideration is given to a detailed model of the entire network, which may lead to a large calculation error. Under the premise of ensuring the data and information security of Supervisory Control and Data Acquisition between different regional power grid operation control centres, the purpose of this paper is to reduce calculation error simply by using the data of a local power network.

Design/methodology/approach

According to the calculation methodology of “decomposition and coordination” and the power balance equation of an interconnected power grid, an improved radial equivalent independent (REI) equivalent method, which can reflect the dynamic characteristics of interconnected power grids to a certain extent, is proposed in this paper. A mathematical model of multi-area-grid L indicator synergic computing is derived as well.

Findings

With the calculation of Institute of Electrical and Electronics Engineers (IEEE) standard grids and an actual grid model, it is proven that the method proposed in this paper can significantly improve the accuracy of the regional power grid L indicator calculation and achieve the synergic computing of a multi-area power system L indicator, without an increase in data interaction among the regional power grids.

Originality/value

The indicator of voltage stability among multi-area was obtained by using the improved REI equivalent method with the change of the load participation factor. Particularly, the coordinated calculation method can be implemented on a local power grid without knowledge of all the parameters of its interconnection, which can avoid possible leakage of confidential data and information of the system owners.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 36 no. 4
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 2 March 2021

Swetha Katragadda and PVY Jayasree

The fifth-generation technology 5G, the planned successor to 4G, is a new global standard for mobile networks that brings virtual to reality. 5G wireless technology enables the…

185

Abstract

Purpose

The fifth-generation technology 5G, the planned successor to 4G, is a new global standard for mobile networks that brings virtual to reality. 5G wireless technology enables the delivery of high speed, low latency, reliability, 100% coverage and availability to connect number of users as in massive IoT applications.

Design/methodology/approach

With expeditious development in wireless communication, the need for enhanced characteristic antenna design such as the size of the antenna, high data rate, demand in traffic, bandwidth, gain and efficiency increases. Various antenna designs are to be explored to meet the needs and achieve trade-offs between antenna size vs cost, high gain and efficiency vs less loss, high B.W and data rate with the selection of appropriate substrate materials and various gain & isolation enhancement techniques.

Findings

This paper thus gives scope for miniaturized MIMO antenna design for mobile applications at mm-wave frequency range.

Originality/value

This paper thus gives scope for miniaturized MIMO antenna design for mobile applications at mm-wave frequency range.

Details

International Journal of Intelligent Unmanned Systems, vol. 10 no. 1
Type: Research Article
ISSN: 2049-6427

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Article
Publication date: 22 September 2023

Oguz Kose, Tugrul Oktay and Enes Özen

The purpose of this paper is to obtain values that stabilize the lateral and longitudinal flight of the quadrotor for which the morphing amount and the best…

293

Abstract

Purpose

The purpose of this paper is to obtain values that stabilize the lateral and longitudinal flight of the quadrotor for which the morphing amount and the best Proportional-Integral-Derivative (PID) coefficients are determined by using the simultaneous perturbation stochastic approximation (SPSA) optimization algorithm.

Design/methodology/approach

Quadrotor consists of body and arms; there are propellers at the ends of the arms to take off and rotors that rotate them. By reducing the angle between mechanism 1 and the rotors with the horizontal plane, the angle between mechanism 2 and the arms, the rotors rise and different configurations are obtained. Conventional multi-rotor aircraft has a fixed fuselage and does not need a tail rotor to change course as helicopters do. The translational and rotational movements are provided by the rotation of the rotors of the aircraft at different speeds by creating moments about the geometric center in 6-degree-of-freedom (DOF) space. These commands sent from the ground are provided by the flight control board in the aircraft. The longitudinal and lateral flight stability and properties of different configurations evaluated by dynamic analysis and simulations in 6 DOF spaces are investigated. An algorithm and PID controller are being developed using SPSA to achieve in-flight position and attitude control of an active deformable aircraft. The results are compared with the results of the literature review and the results of the previous article.

Findings

With SPSA, the best PID coefficients were obtained in case of morphing.

Research limitations/implications

The effects of quadrotor arm height and hub angle changes affect flight stability. With the SPSA optimization method presented in this study, the attitude is quickly stabilized.

Practical implications

With the optimization method, the most suitable PID coefficients and angle values for the lateral and longitudinal flight stability of the quadrotor are obtained.

Social implications

The transition rate and PID coefficients are determined by using the optimization method, which is advantageous in terms of cost and practicality.

Originality/value

With the proposed method, the aircraft can change shape to adapt to different environments, and the parameters required for more stable flight for each situation will be calculated, and this will be obtained more quickly and safely with the SPSA optimization method.

Details

Aircraft Engineering and Aerospace Technology, vol. 95 no. 10
Type: Research Article
ISSN: 1748-8842

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Article
Publication date: 17 October 2023

Massimo Mariani, Mavie Cardi, Francesco D'Ercole, Nicola Raimo and Filippo Vitolla

Understanding the determinants of a corporate initial public offering (IPO) success is essential for reducing investors' valuation uncertainty when participating in share…

491

Abstract

Purpose

Understanding the determinants of a corporate initial public offering (IPO) success is essential for reducing investors' valuation uncertainty when participating in share offerings. In this sense, this study contributes to the existing debate by examining IPO prospectus readability. The authors specifically investigate how clear and more informative insights into pure corporate key financial numbers can lead to a higher valuation for the company after the listing process.

Design/methodology/approach

Through a sample of European IPOs, the authors employ a cross-sectional regression to test the relationship between prospectus readability through the Flesch reading ease (FRE) score and companies' market-to-book ratio at the period end date after the listing process.

Findings

The study findings show a positive impact of higher readability on the post-IPO market-to-book ratio. Thus, clear and more informative communication results in stocks being traded at a premium to their book value. This study presents a concrete call for firms to increase corporate documents’ readability to mitigate the risk of withdrawing or spoiling corporate market access. Specifically, enhanced clarity and transparency increase investors' confidence, facilitating a better understanding of companies' intrinsic value and the overall IPO process. The authors conducted several tests to validate the results.

Originality/value

To the best of the authors’ knowledge, this is among the first works to explore the relationship between the readability of corporate prospectus and the sustained IPO success in the European context.

Details

Journal of Accounting Literature, vol. 47 no. 1
Type: Research Article
ISSN: 0737-4607

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Article
Publication date: 6 November 2019

Alba Manresa, Andrea Bikfalvi and Alexandra Simon

Over recent years, firms have been implementing novel human resource practices. The purpose of this paper is to analyse four specific training practices to determine if and up to…

2367

Abstract

Purpose

Over recent years, firms have been implementing novel human resource practices. The purpose of this paper is to analyse four specific training practices to determine if and up to what extent the adoption of such practices affects innovation and financial performance.

Design/methodology/approach

A Spanish sub-sample of the European Manufacturing Survey is used to contain the responses of 162 manufacturing firms.

Findings

The positive relation between T&D practices and innovative performance was partially accepted, as new-to-the-firm products and new services had a significant relation with these practices. Conversely, the hypothesis stating that there is a positive relation between a new-to-the-market product and the aforementioned T&D practices was rejected. Furthermore, the positive relation between these and financial performance was partially accepted.

Research limitations/implications

This research presents the following limitation: the small number of responses restricts the general reliability of the findings. The inclusion of other countries’ data using the same questionnaire would further enrich the analysis.

Practical implications

First, general training and development is not enough; thus, the present study evidences the positive results of specific training practices such as training and development for creativity and innovation (TD4CI) on firm performances. Second, it also reveals a relation between training practices and innovation by differentiating among the three dimensions of innovation (new product to the firm, new product to the market and new services). Moreover, the present research highlights the benefits of implementing these types of practices, not only for innovation performance but also for financial performance. This paper also suggests that not all the training practices have the same impact on firm performance. Consequently, the company should be clear about their main aim to obtain the highest performance. The third contribution is based on the Spanish context wherein training is not considered as an important organisational function. Thus, this study provides positive results showing that TD4CI might enhance firm performance. Last, the degree of detail of the different training practices analysed, the recent nature of the data related to their implementation and the link between implementation and organisation performance are also part of the contribution of the present analyses.

Originality/value

This research offers recent and relevant data about implementing novel T&D practices and their relation with firm performance.

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Article
Publication date: 1 July 2021

Mohammed Ayoub Ledhem

The purpose of this paper is to apply various data mining techniques for predicting the financial performance of Islamic banking in Indonesia through the main exogenous…

1027

Abstract

Purpose

The purpose of this paper is to apply various data mining techniques for predicting the financial performance of Islamic banking in Indonesia through the main exogenous determinants of profitability by choosing the best data mining technique based on the criteria of the highest accuracy score of testing and training.

Design/methodology/approach

This paper used data mining techniques to predict the financial performance of Islamic banking by applying all of LASSO regression, random forest (RF), artificial neural networks and k-nearest neighbor (KNN) over monthly data sets of all the full-fledged Islamic banks working in Indonesia from January 2011 until March 2020. This study used return on assets as a real measurement of financial performance, whereas the capital adequacy ratio, asset quality and liquidity management were used as exogenous determinants of financial performance.

Findings

The experimental results showed that the optimal task for predicting the financial performance of Islamic banking in Indonesia is the KNN technique, which affords the best-predicting accuracy, and gives the optimal knowledge from the financial performance of Islamic banking determinants in Indonesia. As well, the RF provides closer values to the optimal accuracy of the KNN, which makes it another robust technique in predicting the financial performance of Islamic banking.

Research limitations/implications

This paper restricted modeling the financial performance of Islamic banking to profitability through the main determinants of return of assets in Indonesia. Future research could consider enlarging the modeling of financial performance using other models such as CAMELS and Z-Score to predict the financial performance of Islamic banking under data mining techniques.

Practical implications

Owing to the lack of using data mining techniques in the Islamic banking sector, this paper would fill the literature gap by providing new effective techniques for predicting financial performance in the Islamic banking sector using data mining approaches, which can be efficient tools in business and management modeling for financial researchers and decision-makers in the Islamic banking sector.

Originality/value

According to the author’s knowledge, this paper is the first that provides data mining techniques for predicting the financial performance of the Islamic banking sector in Indonesia.

Details

Journal of Modelling in Management, vol. 17 no. 3
Type: Research Article
ISSN: 1746-5664

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Article
Publication date: 29 March 2024

Aminuddin Suhaimi, Izni Syahrizal Ibrahim and Mariyana Aida Ab Kadir

This review paper seeks to enhance knowledge of how pre-loading affects reinforced concrete (RC) beams under fire. It investigates key factors like deflection and load capacity to…

41

Abstract

Purpose

This review paper seeks to enhance knowledge of how pre-loading affects reinforced concrete (RC) beams under fire. It investigates key factors like deflection and load capacity to understand pre-loading's role in replicating RC beams' actual responses to fire, aiming to improve fire testing protocols and structural fire engineering design.

Design/methodology/approach

This review systematically aggregates data from existing literature on the fire response of RC beams, comparing scenarios with (WP) and without pre-loading (WOP). Through statistical tools like the two-tailed t-test and Mann–Whitney U-test, it assesses deflection extremes. The study further examines structural responses, including flexural and shear behavior, ultimate load capacity, post-yield behavior, stiffness degradation and failure modes. The approach concludes with a statistical forecast of ideal pre-load levels to elevate experimental precision and enhance fire safety standards.

Findings

The review concludes that pre-loading profoundly affects the fire response of RC beams, suggesting a 35%–65% structural capacity range for realistic simulations. The review also recommended the initial crack load as an alternative metric for determining the pre-loading impact. Crucially, it highlights that pre-loading not only influences the fire response but also significantly alters the overall structural behavior of the RC beams.

Originality/value

The review advances structural fire engineering with an in-depth analysis of pre-loading's impact on RC beams during fire exposure, establishing a validated pre-load range through thorough statistical analysis and examination of previous research. It refines experimental methodologies and structural design accuracy, ultimately bolstering fire safety protocols.

Details

Journal of Structural Fire Engineering, vol. 15 no. 4
Type: Research Article
ISSN: 2040-2317

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