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1 – 10 of 14Dhanalakshmi K.M., Kavya G. and Rajkumar S.
This paper aims to propose a single element, dual feed, polarisation diversity antenna. The proposed antenna operates from 2.9 to 10.6 GHz for covering the entire ultra-wideband…
Abstract
Purpose
This paper aims to propose a single element, dual feed, polarisation diversity antenna. The proposed antenna operates from 2.9 to 10.6 GHz for covering the entire ultra-wideband (UWB) frequency range. The antenna is designed for usage in massive multiple input multiple output (MIMO) and closed packaging applications.
Design/methodology/approach
The size of the antenna is 24 × 24 × 1.6 mm3. The radiating element of the antenna is derived from the Sierpinski–Knopp (SK) fractal geometry for miniaturization of the antenna size. The antenna has a single reflecting stub placed between the two orthogonal feeds, to improve isolation.
Findings
The proposed antenna system exhibits S11 < −10 dB, S21 < −15 dB and stable radiation characteristics in the entire operating region. It also offers an envelope correlation coefficient < 0.01, a diversity gain > 9.9 dB and a capacity loss < 0.4 bps/Hz. The simulated and measured outputs were compared and results were found to be in similarity.
Originality/value
The proposed UWB-MIMO antenna has significant size reduction through usage of SK fractal geometry for radiating element. The antenna uses a single radiating element with dual feed. The stub is between the antenna elements which provide a compact and miniaturized MIMO solution for high density packaging applications. The UWB-MIMO antenna provides an isolation better than −20 dB in the entire UWB operating band.
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Daniel Nygaard Ege, Pasi Aalto and Martin Steinert
This study was conducted to address the methodical shortcomings and high associated cost of understanding the use of new, poorly understood architectural spaces, such as…
Abstract
Purpose
This study was conducted to address the methodical shortcomings and high associated cost of understanding the use of new, poorly understood architectural spaces, such as makerspaces. The proposed quantified method of enhancing current post-occupancy evaluation (POE) practices aims to provide architects, engineers and building professionals with accessible and intuitive data that can be used to conduct comparative studies of spatial changes, understand changes over time (such as those resulting from COVID-19) and verify design intentions after construction through a quantified post-occupancy evaluation.
Design/methodology/approach
In this study, we demonstrate the use of ultra-wideband (UWB) technology to gather, analyze and visualize quantified data showing interactions between people, spaces and objects. The experiment was conducted in a makerspace over a four-day hackathon event with a team of four actively tracked participants.
Findings
The study shows that by moving beyond simply counting people in a space, a more nuanced pattern of interactions can be discovered, documented and analyzed. The ability to automatically visualize findings intuitively in 3D aids architects and visual thinkers to easily grasp the essence of interactions with minimal effort.
Originality/value
By providing a method for better understanding the spatial and temporal interactions between people, objects and spaces, our approach provides valuable feedback in POE. Specifically, our approach aids practitioners in comparing spaces, verifying design intent and speeding up knowledge building when developing new architectural spaces, such as makerspaces.
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Ruifeng Li and Wei Wu
In corridor environments, human-following robot encounter difficulties when the target turning around at the corridor intersections, as walls may cause complete occlusion. This…
Abstract
Purpose
In corridor environments, human-following robot encounter difficulties when the target turning around at the corridor intersections, as walls may cause complete occlusion. This paper aims to propose a collision-free following system for robot to track humans in corridors without a prior map.
Design/methodology/approach
In addition to following a target and avoiding collisions robustly, the proposed system calculates the positions of walls in the environment in real-time. This allows the system to maintain a stable tracking of the target even if it is obscured after turning. The proposed solution is integrated into a four-wheeled differential drive mobile robot to follow a target in a corridor environment in real-world.
Findings
The experimental results demonstrate that the robot equipped with the proposed system is capable of avoiding obstacles and following a human target robustly in the corridors. Moreover, the robot achieves a 90% success rate in maintaining a stable tracking of the target after the target turns around a corner with high speed.
Originality/value
This paper proposes a human target following system incorporating three novel features: a path planning method based on wall positions is introduced to ensure stable tracking of the target even when it is obscured due to target turns; improvements are made to the random sample consensus (RANSAC) algorithm, enhancing its accuracy in calculating wall positions. The system is integrated into a four-wheeled differential drive mobile robot effectively demonstrates its remarkable robustness and real-time performance.
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Atul 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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Ewa Wanda Maruszewska, Małgorzata Niesiobędzka and Sabina Kołodziej
The study aims to investigate the impact of indirectly evoked incentives, in the form of supervisor’s preferences, on the decision about accounting policy regarding depreciation…
Abstract
Purpose
The study aims to investigate the impact of indirectly evoked incentives, in the form of supervisor’s preferences, on the decision about accounting policy regarding depreciation method selection and to examine subsequent post-decision distortion by evaluating the depreciation method.
Design/methodology/approach
The authors conducted two experiments with control and treatment groups, manipulating the supervisor’s indirectly evoked preferences. In Study 2, the authors also measured the evaluation of both depreciation methods to investigate post-decisional distortion regarding the assessment of the depreciation method chosen in a decision task. Study 1 was conducted among 85 accounting students, while Study 2 consisted of 200 accountants.
Findings
Both studies revealed the significant impact of supervisor’s indirectly evoked preferences on accounting policy decisions. Participants who were aware of supervisors’ preferences were more likely to choose the depreciation method that was consistent with those preferences. The authors also found that those participants attached a higher value to the depreciation method, providing evidence that adherence to the supervisor’s preferences results in a distorted assessment of the depreciation methods.
Originality/value
First, this study shows that indirectly evoked supervisors’ preferences may lead to a departure from substantive criteria resulting in low-quality accounting outcomes. Second, the assessment of the depreciation method is inseparable from the situational context, as the evaluation of the depreciation method is interdependent upon the preferences of the choice of a depreciation method and the fulfillment of those preferences.
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Asli Pelin Gurgun, Kerim Koc and Handan Kunkcu
Completing construction projects within the planned schedule has widely been considered as one of the major project success factors. This study investigates the use of…
Abstract
Purpose
Completing construction projects within the planned schedule has widely been considered as one of the major project success factors. This study investigates the use of technologies to address delays in construction projects and aims to address three research questions (1) to identify the adopted technologies and proposed solutions in the literature, (2) to explore the reasons why the delays cannot be prevented despite disruptive technologies and (3) to determine the major strategies to prevent delays in construction projects.
Design/methodology/approach
In total, 208 research articles that used innovative technologies, methods, or tools to avoid delays in construction projects were investigated by conducting a comprehensive literature review. An elaborative content analysis was performed to cover the implemented technologies and their transformation, highlighted research fields in relation to selected technologies, focused delay causes and corresponding delay mitigation strategies and emphasized project types with specific delay causes. According to the analysis results, a typological framework with appropriate technological means was proposed.
Findings
The findings revealed that several tools such as planning, imaging, geo-spatial data collection, machine learning and optimization have widely been adopted to address specific delay causes. It was also observed that strategies to address various delay causes throughout the life cycle of construction projects have been overlooked in the literature. The findings of the present research underpin the trends and technological advances to address significant delay causes.
Originality/value
Despite the technological advancements in the digitalization era of Industry 4.0, many construction projects still suffer from poor schedule performance. However, the reason of this is questionable and has not been investigated thoroughly.
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H.P.M.N.L.B. Moragane, B.A.K.S. Perera, Asha Dulanjalie Palihakkara and Biyanka Ekanayake
Construction progress monitoring (CPM) is considered a difficult and tedious task in construction projects, which focuses on identifying discrepancies between the as-built product…
Abstract
Purpose
Construction progress monitoring (CPM) is considered a difficult and tedious task in construction projects, which focuses on identifying discrepancies between the as-built product and the as-planned design. Computer vision (CV) technology is applied to automate the CPM process. However, the synergy between the CV and CPM in literature and industry practice is lacking. This study aims to fulfil this research gap.
Design/methodology/approach
A Delphi qualitative approach was used in this study by conducting two interview rounds. The collected data was analysed using manual content analysis.
Findings
This study identified seven stages of CPM; data acquisition, information retrieval, verification, progress estimation and comparison, visualisation of the results and schedule updating. Factors such as higher accuracy in data, less labourious process, efficiency and near real-time access are some of the significant enablers in instigating CV for CPM. Major challenges identified were occlusions and lighting issues in the site images and lack of support from the management. The challenges can be easily overcome by implementing suitable strategies such as familiarisation of the workforce with CV technology and application of CV research for the construction industry to grow with the technology in line with other industries.
Originality/value
This study addresses the gap pertaining to the synergy between the CV in CPM literature and the industry practice. This research contributes by enabling the construction personnel to identify the shortcomings and the opportunities to apply automated technologies concerning each stage in the progress monitoring process.
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Andrew Ebekozien, Wellington Didibhuku Thwala, Clinton Ohis Aigbavboa and Mohamad Shaharudin Samsurijan
Studies showed that construction digitalisation could prevent or mitigate accidents rate on sites. Digitalisation applications may prevent or mitigate building project collapse…
Abstract
Purpose
Studies showed that construction digitalisation could prevent or mitigate accidents rate on sites. Digitalisation applications may prevent or mitigate building project collapse (BPC) but with some encumbrances, especially in developing countries. There is a paucity of research on digital technologies application to prevent or mitigate BPC in Nigeria. Thus, the research aims to explore the perceived barriers that may hinder digital technologies from preventing or mitigating building collapse and recommend measures to improve technology applications during development.
Design/methodology/approach
The study is exploratory because of the unexplored approach. The researchers collected data from knowledgeable participants in digitalisation and building collapse in Nigeria. The research employed a phenomenology approach and analysed collected data via a thematic approach. The study achieved saturation at the 29th interviewee.
Findings
Findings show that lax construction digitalisation implementation, absence of regulatory framework, lax policy, unsafe fieldworkers' behaviours, absence of basic infrastructure, government attitude, hesitation to implement and high technology budget, especially in developing countries, are threats to curbing building collapse menace via digitalisation. The study identified technologies relevant to preventing or mitigating building collapse. Also, it proffered measures to prevent or mitigate building collapse via improved digital technology applications during development.
Originality/value
This research contributes to the construction digitalisation literature, especially in developing countries, and investigates the perceived barriers that may hinder digital technologies usage in preventing or mitigating building collapse in Nigeria.
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Rafiu King Raji, Jian Lin Han, Zixing Li and Lihua Gong
At the moment, in terms of both research and commercial products, smart shoe technology and applications seem not to attract the same magnitude of attention compared to smart…
Abstract
Purpose
At the moment, in terms of both research and commercial products, smart shoe technology and applications seem not to attract the same magnitude of attention compared to smart garments and other smart wearables such as wrist watches and wrist bands. The purpose of this study is to fill this knowledge gap by discussing issues regarding smart shoe sensing technologies, smart shoe sensor placements, factors that affect sensor placements and finally the areas of smart shoe applications.
Design/methodology/approach
Through a review of relevant literature, this study first and foremost attempts to explain what constitutes a smart shoe and subsequently discusses the current trends in smart shoe applications. Discussed in this study are relevant sensing technologies, sensor placement and areas of smart shoe applications.
Findings
This study outlined 13 important areas of smart shoe applications. It also uncovered that majority of smart shoe functionality are physical activity tracking, health rehabilitation and ambulation assistance for the blind. Also highlighted in this review are some of the bottlenecks of smart shoe development.
Originality/value
To the best of the authors’ knowledge, this is the first comprehensive review paper focused on smart shoe applications, and therefore serves as an apt reference for researchers within the field of smart footwear.
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Orcun Kepez and Selin Üst
The aim of this study is to understand the effect of class configurations in an active learning classroom (ALC) on students' self-perception of experiences and learning outcomes…
Abstract
Purpose
The aim of this study is to understand the effect of class configurations in an active learning classroom (ALC) on students' self-perception of experiences and learning outcomes, namely participation, performance, motivation and creativity.
Design/methodology/approach
A self-administered survey (N = 131) was conducted in seven classes from the varied disciplines of communication, interior design and architecture. During the first half of the semester, all selected courses were conducted in traditional classrooms, whereas those in the second half were conducted in an ALC. ALC was designed to be used with several furniture configurations which could be easily set up by members of the learning community themselves. The survey was conducted at the end of semester before final exams, when students have a clear idea of the experiences in both the traditional and the new (ALC) classrooms, having spent equal time in each of these learning environments.
Findings
The main finding of the study is that students were eager to have future classes in the ALC rather than in traditional settings since the students experienced better learning outcomes in the ALC. During the second half of the semester, students who were in classes conducted following active learning (AL) pedagogies, with its supportive spatial configurations, were more aware of the learning outcomes facilitated by the physical environment. Further, the authors found that the increase in the number of furniture configurations has a statistically significant positive impact on learning outcomes.
Originality/value
AL pedagogy is often studied as a way of teaching and rarely with its associated classroom environments. In most of the existing studies, the configuration of furniture has often been overlooked within an AL environment by a learning community. This study fills the gap in emphasising the spatial aspects of the ALC by focusing on the specific pedagogy being followed.
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