Search results

1 – 10 of 373
Per page
102050
Citations:
Loading...
Access Restricted. View access options
Article
Publication date: 5 March 2018

Bin Xia, Junmo Yeon and Chang Seop Koh

This paper aims to propose a numerically efficient multi-objective optimization strategy, which can improve both the efficiency and performance during the optimization process.

110

Abstract

Purpose

This paper aims to propose a numerically efficient multi-objective optimization strategy, which can improve both the efficiency and performance during the optimization process.

Design/methodology/approach

This paper discusses the multi-objective optimization algorithm by combining multi-objective differential evolution (MODE) algorithm with an adaptive dynamic Taylor Kriging (ADTK) model.

Findings

The proposed approach is validated through application to an analytic example and applied to a shape optimal design of a multi-layered interior permanent magnet synchronous motor for torque ripple reduction while maintaining the average torque.

Originality/value

The ADTK model selects its basis functions adaptively and dynamically so that it may have better accuracy than any other Kriging models. Through adaptive insertion of new sampling data, it guarantees minimum required sampling data for a desired fitting accuracy.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 37 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

Access Restricted. View access options
Article
Publication date: 15 August 2016

Behrokh Khoshnevis, Xiao Yuan, Behnam Zahiri, Jing Zhang and Bin Xia

This paper aims to report on the experiments with the Contour Crafting Automated Construction process using sulfur concrete as the choice of construction material.

1264

Abstract

Purpose

This paper aims to report on the experiments with the Contour Crafting Automated Construction process using sulfur concrete as the choice of construction material.

Design/methodology/approach

Several experiments have been performed at centimeter and meter scales. A finite element analysis simulation model for the behavior of sulfur concrete-based structures has been developed. Experimental results were compared with the results of simulation.

Findings

Sulfur concrete has numerous terrestrial applications and is potentially an ideal construction material for planetary construction.

Originality/value

Experimental samples of sulfur concrete were fabricated using a novel mixer/extrusion system. The mechanism was proven to be durable and stable after more than 500 h of work.

Details

Rapid Prototyping Journal, vol. 22 no. 5
Type: Research Article
ISSN: 1355-2546

Keywords

Access Restricted. View access options
Article
Publication date: 4 August 2023

Zhiqi Liu, Tanghong Liu, Hongrui Gao, Houyu Gu, Yutao Xia and Bin Xu

Constructing porous wind barriers is one of the most effective approaches to increase the running safety of trains on viaducts in crosswinds. This paper aims to further improve…

211

Abstract

Purpose

Constructing porous wind barriers is one of the most effective approaches to increase the running safety of trains on viaducts in crosswinds. This paper aims to further improve the wind-sheltering performance of the porous wind barriers.

Design/methodology/approach

Improved delayed detached eddy simulations based on the k-ω turbulence model were carried out, and the results were validated with wind tunnel tests. The effects of the hole diameter on the flow characteristics and wind-sheltering performance were studied by comparing the wind barriers with the porosity of 21.6% and the hole diameters of 60 mm–360 mm. The flow characteristics above the windward and leeward tracks were analyzed, and the wind-sheltering performance of the wind barriers was assessed using the wind speed reduction coefficients.

Findings

The hole diameters affected the jet behind the wind barriers and the recirculation region above the tracks. Below the top of the wind barriers, the time-averaged velocity first decreased and then increased with the increase in the hole diameter. The wind barrier with the hole diameter of 120 mm had the best wind-sheltering performance for the windward track, but such barrier might lead to overprotection on the leeward track. The wind-sheltering performance of the wind barriers with the hole diameters of 240 mm and 360 mm was significantly degraded, especially above the windward track.

Originality/value

The effects of the hole diameters on the wake and wind-sheltering performance of the wind barriers were studied, by which the theoretical basis is provided for a better design of the porous wind barrier.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 33 no. 11
Type: Research Article
ISSN: 0961-5539

Keywords

Access Restricted. View access options
Article
Publication date: 21 October 2024

Naimat Ullah Shah, Salman Bin Naeem, Rubina Bhatti, Amjid Khan and Xia Wang

The purpose of this study is to determine the level of awareness among library and information science (LIS) professionals regarding the perceived utility of big data (BD) and…

139

Abstract

Purpose

The purpose of this study is to determine the level of awareness among library and information science (LIS) professionals regarding the perceived utility of big data (BD) and data analytics (DA) in academic libraries, as well as their influence on the provision of data services (DSs).

Design/methodology/approach

A cross-sectional survey was carried out to collect the data for this study. The population of this study comprised LIS professionals working in public sector university libraries. A four-factor measurement model estimating the influence of BD and DA on the provision of DSs in academic libraries was tested using the structural equation modelling.

Findings

The findings revealed that awareness (AW) (β = 0.141, CR = 2.534, p = 0.011) demonstrated a significant positive influence on the provision of DSs. The perceived utility of BD (β = 0.058, CR = 0.582, p = 0.561), and perceived utility of DA (β = 0.141, CR = 2.534, p = 0.905) exhibits a positive but statistically non-significant impact on the provision of DSs (β = 0.010, CR = 0.120, p = 0.905). The goodness of fit indices suggest a favourable fit for the model, as evidenced by the following values: χ2 = 1.400, DF = 164; p = 0.001; IFI = 0.954; TLI = 0.946; CFI = 0.953; GFI = 0.906; and RMSEA = 0.043.

Originality/value

A new perspective on the use of BD and DA in academic libraries is presented in this study. It presents a four-factor measurement model on the influence of BD and DA on the provision of DSs in university libraries.

Details

The Electronic Library , vol. 42 no. 6
Type: Research Article
ISSN: 0264-0473

Keywords

Access Restricted. View access options
Article
Publication date: 21 January 2020

Yuxi Yu, Bin Han and Fansen Xia

This paper aims to present wireless passive temperature sensors by using high-temperature stable polymer-derived silicoaluminum carbonitride (PDC-SiAlCN) ceramic materials.

276

Abstract

Purpose

This paper aims to present wireless passive temperature sensors by using high-temperature stable polymer-derived silicoaluminum carbonitride (PDC-SiAlCN) ceramic materials.

Design/methodology/approach

In this paper, a novel PDC-SiAlCN ceramic was synthesized by using polyvinylsilazne and aluminum-tri-sec-butoxide as precursors. Then, PDC-SiAlCN was used as the sensing material to fabricate sensors. The sensors are based on a cavity resonator and an integrated slot antenna. The resonant frequencies of the sensors are determined by the dielectric constants of PDC-SiAlCN ceramic, which monotonically increase versus temperature.

Findings

The effect of sensor dimension on the performance of the sensors was investigated using simulation and experimental methods. The using temperature, reliability and sensing distance of the sensors were studied experimentally. The sensors performed measurement up to 1100°C with excellent reliability and repeatability. The sensing distance varied from 38 to 14 mm when the temperature increasing from 20°C to 1100°C.

Originality/value

PDC-SiAlCN ceramic based wireless passive temperature sensors have the advantage of seamless integration of slot antennas and resonators, which greatly reduces the size of the sensor, reduces the direction of antenna transmission and increases the transmission space. The sensors can be used for many harsh environment applications such as engine monitoring.

Details

Sensor Review, vol. 40 no. 1
Type: Research Article
ISSN: 0260-2288

Keywords

Access Restricted. View access options
Article
Publication date: 5 June 2017

Dan Long, Zi-yao Xia and Wang-bin Hu

The purpose of this paper is to bridge the obvious gap presented in research on antecedents of effectuation by building a research model from the perspectives of effectuation and…

841

Abstract

Purpose

The purpose of this paper is to bridge the obvious gap presented in research on antecedents of effectuation by building a research model from the perspectives of effectuation and entrepreneurial opportunity.

Design/methodology/approach

This paper examines the effects of patterns of opportunity discovery and the innovativeness of entrepreneurial opportunity on the decision-making process of effectuation in new venture creation. Eight hypotheses are put forward and examined by hierarchical multiple logistic regression. The data in this paper are based on the first two rounds of survey data from Chinese Panel Study of Entrepreneurial dynamics.

Findings

The empirical results show that patterns of opportunity discovery have significant positive effects (at least partially) on effectuation. Namely, entrepreneurs employing fortuitous discovery tend to use available means and leverage contingency. And with lower innovativeness of opportunity, entrepreneurs are more likely to use affordable loss and leverage contingency.

Research limitations/implications

The study is limited to each dimension of effectuation based on the single-item measure, which cannot completely reflect the effectual construct. More research should to be done to improve measures of effectuation.

Practical implications

The findings are useful for entrepreneurs to make effective decisions whether to choose effectuation in the face of different patterns of opportunity discovery. Besides, it provides the advice on how to cope with the innovativeness of opportunity and seize entrepreneurial opportunities to entrepreneurs.

Originality/value

This paper first systematically studies the effects of entrepreneurial opportunity on effectuation, making up for the obvious gap of research on antecedents of effectuation.

Access Restricted. View access options
Article
Publication date: 11 October 2018

Cong Ding, Hua Zhu, Guodong Sun, Chun Ling Wei and Yu Jiang

The purpose of this work is to comprehensively reveal the spatial distribution and evolution features of a running-in attractor.

95

Abstract

Purpose

The purpose of this work is to comprehensively reveal the spatial distribution and evolution features of a running-in attractor.

Design/methodology/approach

The friction coefficient signals extracted from wear experiments are reconstructed. A projected matrix is obtained based on the reconstructed matrix. Then the approach of three-dimensional (3D) histogram of phase points is proposed, which is used to intuitively characterize the complex properties of the running-in attractor.

Findings

The space occupied by the running-in attractor gradually contracts, then stabilizes and finally expands; the maximum of phase points number in a certain bin initially decreases, then keeps stable and finally increases rapidly; yet the percentage of bins number storing phase points shows an inverse variation tendency. Consequently, 3D histogram evolves from a nonuniform state to a uniform state then returns back to the nonuniform state, which indicates the evolution rule of “formation, stabilization and disappearance” of the running-in attractor.

Originality/value

Characterization on the features of the running-in attractor can provide valuable information about friction systems and their dynamic behaviors.

Details

Industrial Lubrication and Tribology, vol. 70 no. 9
Type: Research Article
ISSN: 0036-8792

Keywords

Access Restricted. View access options
Article
Publication date: 6 May 2024

Shan Gao, Bin Wang, Xinjie Yao and Quan Yuan

This paper aims to characterize the surface film formed on Alloys 800 and 690 in chloride and thiosulfate-containing solution at 300°C.

56

Abstract

Purpose

This paper aims to characterize the surface film formed on Alloys 800 and 690 in chloride and thiosulfate-containing solution at 300°C.

Design/methodology/approach

Alloy 800 and 690 were immersed in chloride and thiosulfate-containing solution at 300°C up to five days, and then the surface film was analyzed by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and energy dispersive X-ray spectrometers (EDX).

Findings

Through static immersion experiments in a high-temperature and high-pressure water environment, the alloy samples covered by surface film after five days of immersion were obtained. The morphology of the surface film was characterized at both horizontal and cross-sectional scales using SEM and focused ion beam-TEM techniques. It was observed that due to the influence of the quartz lining, the surface film primarily exhibited a bilayered structure. The first layer contained a significant amount of SiO2, with a higher content of metal hydroxides compared to metal oxides. The second layer was predominantly composed of Fe, Ni and Cr, with a higher content of metal oxides compared to metal hydroxides.

Originality/value

The results showed that the materials of the lining of the autoclave could significantly influence the film composition of the tested material, which should be paid attention when analyzing the corrosion mechanism at high temperature.

Details

Anti-Corrosion Methods and Materials, vol. 71 no. 5
Type: Research Article
ISSN: 0003-5599

Keywords

Access Restricted. View access options
Article
Publication date: 17 October 2024

Abeer Alshwiah

This research aims to evaluate students’ perception of using a chatbot to develop their understanding of the various parts of a research article, and their ability to apply what…

112

Abstract

Purpose

This research aims to evaluate students’ perception of using a chatbot to develop their understanding of the various parts of a research article, and their ability to apply what they have learned to write a new research plan.

Design/methodology/approach

This research is qualitative in approach. The sample contained 10 students on a research skills course as part of the master of educational technologies program. The research instruments consisted of (1) semi-structured interviews to gather the students’ perceptions of the effectiveness of using a chatbot, and (2) observation notes to triangulate the interview results, relating to the students’ application of what they had learned from the teacher and ChatGPT, in new contexts.

Findings

This study found that the use of ChatGPT contributed to developing students’ knowledge of writing a research plan. The students were satisfied with their personalized learning experience, and believed that ChatGPT had improved their autonomy, competence and relatedness. These three variables had played a role in developing their application skill. However, there were concerns about using ChatGPT in learning, like limiting the students’ creativity, human interaction and critical thinking skills. There were also concerns over accuracy, ethics and plagiarism.

Originality/value

The originality of this study lies in its examination of how ChatGPT can help satisfy students' need for autonomy (having more knowledge to communicate with the app and control their choices), competence (feeling more capable of using artificial intelligence [AI] and possessing the necessary knowledge and skills to succeed) and relatedness (being less disappointed when failing to obtain satisfactory responses from the AI application), while improving their skills in application. According to self-determination theory (SDT), these factors affect students’ skills in applying what they have learned to new tasks. Therefore, this study extends the examination of SDT and its effect to include application skill, using qualitative methods to study the relationships between variables in depth.

Details

Qualitative Research Journal, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1443-9883

Keywords

Access Restricted. View access options
Article
Publication date: 19 March 2021

Wai Tung Ho and Fu Wing Yu

This study aims to apply association rule mining (ARM) to uncover specific associations between operating components of a chiller system and improve its coefficient of performance…

282

Abstract

Purpose

This study aims to apply association rule mining (ARM) to uncover specific associations between operating components of a chiller system and improve its coefficient of performance (COP), hence reducing the electricity use of buildings with central air conditioning.

Design/methodology/approach

First, 13 operating variables were identified, comprising measures of temperatures and flow rates of system components and their switching statuses. The variables were grouped into four bins before carrying out ARM. Strong rules were produced to associate the variables and switching statuses with different COP classes.

Findings

The strong rules explain existing constraints on practising chiller sequencing and prioritise variables for optimisation. Based on strong rules for the highest COP class, the optimal operating strategy involves rescheduling chillers and their associated components in pairs during a high load operation. Resetting the chilled water supply temperature is the next best strategy, followed by resetting the condenser water entering temperature, subject to operating constraints.

Research limitations/implications

This study considers the even frequency method with four bins only. Replication work can be done with other discretisation methods and different numbers of classes to compare potential differences in the bin ranges of the optimised variables.

Practical implications

The strong rules identified by ARM highlight associations between variables and high or low COPs. This supports the selection of critical variables and the operating status of system components to maximise the COP. Tailor-made optimisation strategies and the associated electricity savings can be further evaluated.

Originality/value

Previous studies applied ARM for chiller fault detection but without considering system performance under the interaction of different components. The novelty of this study is its demonstration of ARM’s intelligence at discovering associations in past operating data. This enables the identification of tailor-made energy management opportunities, which are essential for all engineering systems. ARM is free from the prediction errors of typical regression and black-box models.

1 – 10 of 373
Per page
102050