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1 – 10 of 21Atul Varshney and Vipul Sharma
This paper aims to present the design development and measurement of two aerodynamic slotted X-bands back-to-back planer substrate-integrated rectangular waveguide (SIRWG/SIW) to…
Abstract
Purpose
This paper aims to present the design development and measurement of two aerodynamic slotted X-bands back-to-back planer substrate-integrated rectangular waveguide (SIRWG/SIW) to Microstrip (MS) line transition for satellite and RADAR applications. It facilitates the realization of nonplanar (waveguide-based) circuits into planar form for easy integration with other planar (microstrip) devices, circuits and systems. This paper describes the design of a SIW to microstrip transition. The transition is broadband covering the frequency range of 8–12 GHz. The design and interconnection of microwave components like filters, power dividers, resonators, satellite dishes, sensors, transmitters and transponders are further aided by these transitions. A common planar interconnect is designed with better reflection coefficient/return loss (RL) (S11/S22 ≤ 10 dB), transmission coefficient/insertion loss (IL) (S12/S21: 0–3.0 dB) and ultra-wideband bandwidth on low profile FR-4 substrate for X-band and Ku-band functioning to interconnect modern era MIC/MMIC circuits, components and devices.
Design/methodology/approach
Two series of metal via (6 via/row) have been used so that all surface current and electric field vectors are confined within the metallic via-wall in SIW length. Introduced aerodynamic slots in tapered portions achieve excellent impedance matching and tapered junctions with SIW are mitered for fine tuning to achieve minimum reflections and improved transmissions at X-band center frequency.
Findings
Using this method, the measured IL and RLs are found in concord with simulated results in full X-band (8.22–12.4 GHz). RLC T-equivalent and p-equivalent electrical circuits of the proposed design are presented at the end.
Practical implications
The measurement of the prototype has been carried out by an available low-cost X-band microwave bench and with a Keysight E4416A power meter in the microwave laboratory.
Originality/value
The transition is fabricated on FR-4 substrate with compact size 14 mm × 21.35 mm × 1.6 mm and hence economical with IL lie within limits 0.6–1 dB and RL is lower than −10 dB in bandwidth 7.05–17.10 GHz. Because of such outstanding fractional bandwidth (FBW: 100.5%), the transition could also be useful for Ku-band with IL close to 1.6 dB.
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Fatimah De’nan, Nor Salwani Hashim and Mohd Yusri Mohamad Razak
Tapered steel sections are widely used in house building design due to their structural efficiency and aesthetic appearance. Due to the practical usage of web tapering…
Abstract
Purpose
Tapered steel sections are widely used in house building design due to their structural efficiency and aesthetic appearance. Due to the practical usage of web tapering specifications in the metal building industry, fabrication and material expenses are analyzed to achieve geometric and economic productivity. The purpose of this study is to investigate the effectiveness of utilizing web profiles with openings in reducing the weight of steel beams.
Design/methodology/approach
In this paper, the nonlinear analysis of the bending behavior of a tapered steel section with an opening was studied by finite element analysis. The results were then compared with those of the tapered steel section without an opening in terms of displacement and yield moment.
Findings
The bending capacity of a tapered steel section was analyzed using finite element analysis. Results showed that the tapered steel section without openings had a higher bending capacity compared to the section with various sizes of web openings. The results also showed that decreasing the number of openings would increase the bending capacity, whereas increasing the size of the opening would decrease it. The difference in the yield moment between the tapered steel section with and without openings was only 15.818%. A total of 60 nonlinear analyses were conducted to investigate the effect of the number and size of web openings, flange thickness and web thickness on the bending behavior. However, this study showed that web opening with octagon shape and 0.6D size of web opening, where D is the depth of section, showed the best section in terms of yield moment and volume reduction compared to other opening size and shape.
Originality/value
It is also found that tapered steel section has better moment resistance in thicker flange and web. The study is valuable for engineers and designers who work with steel structures and need to optimize the performance of tapered steel sections with web openings.
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João Paulo Vieito, Christian Espinosa, Wing-Keung Wong, Munkh-Ulzii Batmunkh, Enkhbayar Choijil and Mustafa Hussien
It has been argued in the literature that structural changes in the financial markets, such as integration, have the potential to cause herding behavior or correlated behavioral…
Abstract
Purpose
It has been argued in the literature that structural changes in the financial markets, such as integration, have the potential to cause herding behavior or correlated behavioral patterns in traders. The purpose of this study is to investigate whether there is any financial herding behavior in the Latin American Integrated Market (MILA), a transnational stock market composed of Chile, Peru, Colombia and Mexico stock exchanges and whether there is any ARCH or GARCH effect in the herding behavior models.
Design/methodology/approach
This study uses the modified return dispersion approach on daily index return data. The sample period is from January 03, 2002 to May 07, 2019. The data are obtained from the MILA database. To count time-varying volatilities in herding models, the authors run ARCH family regression with GARCH (1,1) settings. Hwang and Salmon (2004) model is used as a robustness test.
Findings
The authors found strong herding behavior under the general market conditions and moderate and partial herding behavior under some specified markets circumstances, such as bull and bear markets and high-low volatility states. Moreover, the pre-MILA period exhibits more herding behavior than the post-MILA period. The empirical results show that most of the ARCH and GARCH effects are statistically significant, implying that the past information of stock returns and market volatility significantly affect the volatility of following periods, which can also explain the formation of herding tendency among investors. Finally, the results of the robustness tests (Hwang and Salmon, 2004) confirm herding in all periods, except full sample period for Mexico and post-MILA period for Mexico and Colombia.
Research limitations/implications
This study investigates the herding behavior in the MILA market in terms of market return, volatility and timing. A limitation of the paper is that the authors have not included other factors on the formation of herding behavior, such as macroeconomic factors, effects of regional or international markets and policy influences. The authors will explore the issue in the extension of the paper.
Practical implications
As MILA is the first virtual integration of stock exchanges without merging, the study provides useful findings and draws good inferences of herding behavior in the MILA market in terms of market return, volatility and timing which are useful for academics, investors and policymakers in their investment and decision makings.
Social implications
The paper provides useful findings and draws good inferences of herding behavior in the MILA market in terms of market return, volatility and timing which are not only useful in practical implications, but also in social implications.
Originality/value
This study contributes to the herding literature by examining four different hypotheses in respect of the unique case of transnational stock exchange without fusions or corporate mergers, where each market maintains its independence and regulatory autonomy. The authors also contribute to the literature by including both ARCH and GARCH effects in the herding behavioral models along the Hwang and Salmon (2004) approach.
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Roger Hosein, Rebecca Gookool, George Saridakis and Sandra Sookram
The phenomenon of growth spillover occurs because of domestic shocks, global shocks and shocks to a foreign country or region, and these are transmitted through specific channels…
Abstract
Purpose
The phenomenon of growth spillover occurs because of domestic shocks, global shocks and shocks to a foreign country or region, and these are transmitted through specific channels. This study investigates the strength of the economic linkages between Caribbean Community (CARICOM) economies and its main traditional partners, including the European Union (EU-27), and emerging trading partners, such as China, with a view to determining the presence and extent of spillover growth which results from the interdependence among these economies. The paper hypothesizes that the presence of these spillovers can be leveraged to chart the future for the region's integration in the global sphere.
Design/methodology/approach
Based on the existing theoretical and empirical literature, a structural vector autoregressive (SVAR) model was developed and employed to examine the strength of the economic linkages between CARICOM economies and its main trading partners, such as the United States (US), the United Kingdom (UK) and the EU-27, alongside some of the non-traditional partners such as China. This method has been widely used by institutions, such as the International Monetary Fund (IMF) and World Bank, to profile economic linkages between economies. To this end, the methodology was formulated based on the IMF Spillover Reports which were produced from 2011 to 2015.
Findings
The model suggests that positive spillovers are likely to occur from continued deepened integration with the US, EU-27 and the UK, as traditional trade partners, but that opportunities also exist from a deliberate deepening of relations with non-traditional trade partners, for example, China. This becomes even more apparent when CARICOM is separated into categories consisting of more developed countries (MDCs) and less developed countries (LDCs). In addition, from the perspective of any trading partner, such as those in the EU-27, this research is relevant and timely as it contributes to the landscape of literature, which can be utilized for the purpose of negotiating parameters of trade and integration arrangements.
Research limitations/implications
This study adds to the literature on evaluating the direction for deepened integration of CARICOM economies, both with selected traditional and non-traditional trade partners as the region pilots recovery in a post-pandemic global space.
Practical implications
Policymakers can use the results of this study to leverage economic spillovers as a basis for determining which trade partners offer the most significant growth benefits as the region recovers from the COVID-19 pandemic and it will also assist in steering regional integration. This result also implies that over time, the comparative advantage structure of CARICOM member countries' export profile should change to reflect the import profile of its trade partners. To this end, this study can be used to inform and better position the respective trade and industrial development policies of countries in the Caribbean region as they attempt to deepen integration regionally and internationally. From the perspective of the partner, traditional trading relationships such as those which exist with European countries, such as the CARIFORUM-EU Economic Partnership Agreement, can be more deliberately utilized given the geographic benefits on offer with deepened relationships with economies in the Caribbean. Further, this research can also be a point of departure for future research.
Originality/value
This study is among the few empirical works that examine spillover effects as a strategy for rebuilding economic growth in the post-COVID 19 era. This study adds to the literature on evaluating the direction for deepened integration of CARICOM economies, both with selected traditional and non-traditional trade partners as the region navigates recovery in a post-pandemic global space.
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Prosun Mandal, Srinjoy Chatterjee and Shankar Chakraborty
In many of today’s manufacturing industries, such as automobile, aerospace, defence, die and mould making, medical and electrical discharge machining (EDM) has emerged as an…
Abstract
Purpose
In many of today’s manufacturing industries, such as automobile, aerospace, defence, die and mould making, medical and electrical discharge machining (EDM) has emerged as an effective material removal process. In this process, a series of discontinuous electric discharges is used for removing material from the workpiece in the form of craters generating a replica of the tool into the workpiece in a dielectric environment. Appropriate selection of the tool electrode material and combination of input parameters is an important requirement for performance enhancement of an EDM process. This paper aims to optimize an EDM process using single-valued neutrosophic grey relational analysis using Cu-multi-walled carbon nanotube (Cu-MWCNT) composite tool electrode.
Design/methodology/approach
This paper proposes the application of grey relational analysis (GRA) in a single-valued neutrosophic fuzzy environment to identify the optimal parametric intermix of an EDM process while considering Cu-MWCNT composite as the tool electrode material. Based on Taguchi’s L9 orthogonal array, nine experiments are conducted at varying combinations of four EDM parameters, i.e. pulse-on time, duty factor, discharge current and gap voltage, with subsequent measurement of two responses, i.e. material removal rate (MRR) and tool wear rate (TWR). The electrodeposition process is used to fabricate the Cu-MWCNT composite tool.
Findings
It is noticed that both the responses would be simultaneously optimized at higher levels of pulse-on time (38 µs) and duty factor (8), moderate level of discharge current (5 A) and lower level of gap voltage (30 V). During bi-objective optimization (maximization of MRR and minimization of TWR) of the said EDM process, the achieved values of MRR and TWR are 243.74 mm3/min and 0.001034 g/min, respectively.
Originality/value
Keeping in mind the type of response under consideration, their measured values for each of the EDM experiments are expressed in terms of linguistic variables which are subsequently converted into single-valued neutrosophic numbers. Integration of GRA with single-valued neutrosophic sets would help in optimizing the said EDM process with the Cu-MWCNT composite tool while simultaneously considering truth-membership, indeterminacy membership and falsity-membership degrees in a human-centric uncertain decision-making environment.
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Zahra Salah Eldin, Mohamed Elsheemy and Raghda Ali Abdelrahman
Many countries around the world are facing great challenges from their ageing population with shrinking workforce, this will put more pressure on their financial system and will…
Abstract
Purpose
Many countries around the world are facing great challenges from their ageing population with shrinking workforce, this will put more pressure on their financial system and will increase the public spending on care costs provided to older people. Egypt is in the phase of establishing a new law for older people care's rights, a law that will organise how older people in need for care would benefit from access to government financial support and how will families support their older relatives financially and how the care costs will be shared between the older people, their families and the government.
Design/methodology/approach
The paper examines the suitability two cost-sharing methods and applying them to assess the effect on the individuals and families' income strain.
Findings
The preferred approach can be used for sharing costs as it applies a gradual funding withdrawal by the government and provide more fairness and flexibility for application in different regions. Besides, the parameters of this approach can be used by policy makers to control the levels of funding.
Originality/value
The paper will be the first to discuss the intergenerational fairness from a financial perspective in Egypt to avoid forcing older people into poverty or resorting to poverty trade-off.
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Wei Wang, Ximing Yin, Ryan Coles and Jin Chen
Current open innovation (OI) and external knowledge search (EKS) research primarily shows a positive linear relationship between EKS and innovation at an individual level…
Abstract
Purpose
Current open innovation (OI) and external knowledge search (EKS) research primarily shows a positive linear relationship between EKS and innovation at an individual level. However, organizational scholarship argues that excessive EKS may harm innovation. This study combines the knowledge-based view (KBV) and attention-based view (ABV) to articulate a nonlinear theory of EKS and innovation at the individual level.
Design/methodology/approach
The authors constructed a multi-sourced dataset covering 59,798 USA pharmaceutical patents spanning from 1975 to 2014 and employed negative binomial fixed-effect models to examine theoretical hypotheses.
Findings
We find a significant concave curvilinear relationship between EKS and innovation quantity as well as innovation quality at an individual level. An individual’s knowledge breadth and depth moderate the relationship between EKS and innovation, such that the threshold at which EKS has diminishing returns for individual innovation is higher for inventors with a broad range of knowledge and those with deeper expertise in the domain where they are innovating.
Research limitations/implications
Managers should guide inventors toward a moderate investment of time and effort in EKS and should caution against over searching. Besides, managers should recognize that an inventor’s capacity for EKS is determined in part by their breadth of knowledge across various domains as well as the depth of knowledge they have in the knowledge domain where they are innovating.
Practical implications
We provide both parties with a clearer understanding of when EKS can begin to deteriorate an individual’s innovation performance why that deterioration occurs, and we also highlight two individual-level knowledge characteristics to take into consideration when deciding when to cease the EKS process.
Social implications
This study provides a novel holistic understanding of OI and knowledge management for policymakers and organizations to nourish innovation dynamism and make the best of knowledge stocks in the community, which in turn will create endless power for sustainable social change and inclusive development.
Originality/value
This study contributes to OI theory by highlighting the non-linear nature of the relationship between EKS and innovation on an individual level. This represents a fundamental shift in theory on EKS and individual innovation by suggesting a major rethinking of how the two concepts relate, revealing the dark side of EKS in knowledge management if inventors engage in excessive EKS. Likewise, our study’s incorporation of the ABV informs KBV scholarship by highlighting the role of the limited attentional capacity of individuals in firm knowledge management.
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A smart city integrates a comprehensive suite of technologies, which inherently require data to function effectively. It is designed with the intention of amassing all available…
Abstract
Purpose
A smart city integrates a comprehensive suite of technologies, which inherently require data to function effectively. It is designed with the intention of amassing all available data concerning machines, devices, infrastructure, individuals and their surroundings. This commentary addresses the evolution of smart cities over time, the increasing extent of data collection, the growing pressure on personal privacy and people's reactions to these trends. The article highlights the contradiction between the needs of the city and the desires of its inhabitants. It notes that people react differently to gradual versus abrupt changes in data-collecting technologies and services. It also suggests that more work needs to be done to prepare both smart cities and the human population for a sustainable, mutually beneficial future.
Design/methodology/approach
This commentary presents a viewpoint on the subject of data collection and privacy in smart cities, drawing on various sources to support its observations and conclusions.
Findings
The primary focus of this discussion is on the technological evolution of the cities. It emphasizes that, as cities get smarter, they offer more conveniences in exchange for various types of data, highlighting the likelihood that pressure on personal privacy will continue to escalate. This is due to the increasing pervasiveness of data-collecting technologies in every aspect of lives and urban environments. These environments are expected to become progressively smarter each year. Given this context, and to ensure a seamless transition to smart and sustainable cities, it is imperative that today's privacy discussions start to focus not only just on the existing but also on the future conditions and challenges that citizens are expected to encounter.
Originality/value
This commentary delves into the existing gaps in understanding the contradiction between the data-collection “needs” of smart cities, the direction in which the cities are evolving and people's awareness of how much data they will have to surrender in the future. It also highlights the risk of people gradually relinquishing nearly all their privacy, often without noticing, in exchange for the ever-increasing conveniences offered by smart cities.
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Opeoluwa Adeniyi Adeosun, Suhaib Anagreh, Mosab I. Tabash and Xuan Vinh Vo
This paper aims to examine the return and volatility transmission among economic policy uncertainty (EPU), geopolitical risk (GPR), their interaction (EPGR) and five tradable…
Abstract
Purpose
This paper aims to examine the return and volatility transmission among economic policy uncertainty (EPU), geopolitical risk (GPR), their interaction (EPGR) and five tradable precious metals: gold, silver, platinum, palladium and rhodium.
Design/methodology/approach
Applying time-varying parameter vector autoregression (TVP-VAR) frequency-based connectedness approach to a data set spanning from January 1997 to February 2023, the study analyzes return and volatility connectedness separately, providing insights into how the data, in return and volatility forms, differ across time and frequency.
Findings
The results of the return connectedness show that gold, palladium and silver are affected more by EPU in the short term, while all precious metals are influenced by GPR in the short term. EPGR exhibits strong contributions to the system due to its elevated levels of policy uncertainty and extreme global risks. Palladium shows the highest reaction to EPGR, while silver shows the lowest. Return spillovers are generally time-varying and spike during critical global events. The volatility connectedness is long-term driven, suggesting that uncertainty and risk factors influence market participants’ long-term expectations. Notable peaks in total connectedness occurred during the Global Financial Crisis and the COVID-19 pandemic, with the latter being the highest.
Originality/value
Using the recently updated news-based uncertainty indicators, the study examines the time and frequency connectedness between key uncertainty measures and precious metals in their returns and volatility forms using the TVP-VAR frequency-based connectedness approach.
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Xinyang Liu, Anyu Liu, Xiaoying Jiao and Zhen Liu
The purpose of the study is to investigate the impact of implementing anti-dumping duties on imported Australian wine to China in the short- and long-run, respectively.
Abstract
Purpose
The purpose of the study is to investigate the impact of implementing anti-dumping duties on imported Australian wine to China in the short- and long-run, respectively.
Design/methodology/approach
First, the Difference-in-Differences (DID) method is used in this study to evaluate the short-run causal effect of implementing anti-dumping duties on imported Australian wine to China. Second, a Bayesian ensemble method is used to predict 2023–2025 wine exports from Australia to China. The disparity between the forecasts and counterfactual prediction which assumes no anti-dumping duties represents the accumulated impact of the anti-dumping duties in the long run.
Findings
The anti-dumping duties resulted in a significant decline in red and rose, white and sparkling wine exports to China by 92.59%, 99.06% and 90.06%, respectively, in 2021. In the long run, wine exports to China are projected to continue this downward trend, with an average annual growth rate of −21.92%, −38.90% and −9.54% for the three types of wine, respectively. In contrast, the counterfactual prediction indicates an increase of 3.20%, 20.37% and 4.55% for the respective categories. Consequently, the policy intervention is expected to result in a decrease of 96.11%, 93.15% and 84.11% in red and rose, white and sparkling wine exports to China from 2021 to 2025.
Originality/value
The originality of this study lies in the creation of an economic paradigm for assessing policy impacts within the realm of wine economics. Methodologically, it also represents the pioneering application of the DID and Bayesian ensemble forecasting methods within the field of wine economics.
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