Shuling Zhou, Xi Zhang, Juan Liu, Kaihua Zhang and Yuqing Zhao
Smart cities show a “booming” trend both in the academia and the industry in recent years. Scholars across the world have been investigating how new technologies are applied to…
Abstract
Purpose
Smart cities show a “booming” trend both in the academia and the industry in recent years. Scholars across the world have been investigating how new technologies are applied to develop new services to the inhabitants and cities all over the world also address the “smart cities” challenges by promoting policymaking and governance. This paper aims to conduct in-depth research on smart cities by combining the study of governance policy study and information technology study.
Design/methodology/approach
This paper empirically mapped the trends of smart city development, outstanding scholars and hot topics about smart cities by analyzing important references using CiteSpace. The authors visualized references and topics to analyze smart city research, based on empirical data from Web of Science. Furthermore, two most important research branches – topics from smart city governance research and those from information systems (IS) research were studied, respectively.
Findings
First, the authors mapped the development of research and divided the development into three different stages. Second, the authors explored important, influential and instructive publications and publications’ attributes including authors, institutions, journals and topics. Third, the authors found there are different characteristics between the IS group and the governance group in publication situations, influential institutions, journals and authors, although the research points of the two branches are overlapping and fragmented. Finally, the authors proposed important topics, which include “internet of things (IoT)”, “big data”, “smart city systems” and “smart city management” and the authors predicted that “IoT” and “smart city challenge” would be future trends in recent years.
Originality/value
This study is an innovative research of its category because it visualized the development of smart city research, analyzed both governance and technology branches of smart city research synthetically using CiteSpace and forecasted future trends of smart city research by topics analysis and visualization of evolution.
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Xingwen Wu, Zhenxian Zhang, Wubin Cai, Ningrui Yang, Xuesong Jin, Ping Wang, Zefeng Wen, Maoru Chi, Shuling Liang and Yunhua Huang
This review aims to give a critical view of the wheel/rail high frequency vibration-induced vibration fatigue in railway bogie.
Abstract
Purpose
This review aims to give a critical view of the wheel/rail high frequency vibration-induced vibration fatigue in railway bogie.
Design/methodology/approach
Vibration fatigue of railway bogie arising from the wheel/rail high frequency vibration has become the main concern of railway operators. Previous reviews usually focused on the formation mechanism of wheel/rail high frequency vibration. This paper thus gives a critical review of the vibration fatigue of railway bogie owing to the short-pitch irregularities-induced high frequency vibration, including a brief introduction of short-pitch irregularities, associated high frequency vibration in railway bogie, typical vibration fatigue failure cases of railway bogie and methodologies used for the assessment of vibration fatigue and research gaps.
Findings
The results showed that the resulting excitation frequencies of short-pitch irregularity vary substantially due to different track types and formation mechanisms. The axle box-mounted components are much more vulnerable to vibration fatigue compared with other components. The wheel polygonal wear and rail corrugation-induced high frequency vibration is the main driving force of fatigue failure, and the fatigue crack usually initiates from the defect of the weld seam. Vibration spectrum for attachments of railway bogie defined in the standard underestimates the vibration level arising from the short-pitch irregularities. The current investigations on vibration fatigue mainly focus on the methods to improve the accuracy of fatigue damage assessment, and a systematical design method for vibration fatigue remains a huge gap to improve the survival probability when the rail vehicle is subjected to vibration fatigue.
Originality/value
The research can facilitate the development of a new methodology to improve the fatigue life of railway vehicles when subjected to wheel/rail high frequency vibration.
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The purpose of this paper is to synthesise a novel wet-rubbing fastness improver with diphenylmethane diisocyanate (MDI), polyethylene glycol (PEG), dimethylol propionic acid…
Abstract
Purpose
The purpose of this paper is to synthesise a novel wet-rubbing fastness improver with diphenylmethane diisocyanate (MDI), polyethylene glycol (PEG), dimethylol propionic acid (DMPA), diethylenetriamine and epichlorohydrin.
Design/methodology/approach
The synthetic reaction was carried out through three steps: pre-polymerising, chain-extending and chemically modifying. The influence of monomers dosage and ratio, temperature and time on reaction system and wet-rubbing fastness of reactive dye is studied. The target product was characterised by transform infrared spectroscopy analysis.
Findings
The optimum synthetic process condition of the improver is as follows: reaction temperature 100°C; pre-polymering time 2.5 hours with R value [n(NCO): n(OH)] 1.35 and DMPA 7 per cent (on percentage of total moles of MDI and PEG); chain-extending time 30 minutes with diethylenetriamine 1.5 per cent (on percentage of total moles of MDI and PEG); modifying time 2 hours with diethylenetriamine : epichlorohydrin = 1:2 (mole ratio).
Practical implications
The synthetic product is a three-functions-in-one (filming, salt-forming and cross-linking) wet-rubbing fastness improver which can obviously improve the wet-rubbing fastness of reactive dyes from Grade 2-3 to Grade 4.
Originality/value
The wet-rubbing fastness improver is novel and could find numerous applications in dyeing and finishing.
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Yunlong Duan, Shuling Liu, Chang MU, Xiangwei Liu, Edwin Cheng and Yongsong Liu
This study aims to analyze the moderating effect of managerial discretion on the relationship between cross-border knowledge search and the high-tech firms’ innovation quality in…
Abstract
Purpose
This study aims to analyze the moderating effect of managerial discretion on the relationship between cross-border knowledge search and the high-tech firms’ innovation quality in a global health emergency and addresses the following issues: the influence mechanism of different types of cross-border knowledge search on the high-tech firms’ innovation quality in a global health emergency; and the moderating role of different dimensions of manager discretion on the above relationship.
Design/methodology/approach
Based on the firms’ strategy selection methods, the authors divided cross-border knowledge search into three aspects, namely, breadth, depth and balance, and analyzed the impact of cross-border knowledge search on the innovation quality of high-tech firms in a global health emergency, taking managerial discretion as the moderating variable, and divided it into position rights, pay rights and operation rights according to the key rights of firms’ strategic management. Furthermore, the authors constructed a theoretical model, and for an analysis sample, the authors collected data from Chinese high-tech firms from 2013 to 2021.
Findings
The empirical results show that there is an inverted U-shaped relationship between cross-border knowledge search breadth, depth and balance and the innovation quality of high-tech firms. The position rights, pay rights and operation rights of managerial discretion have partially significant moderating effects on the relationship between cross-border knowledge search breadth, depth and balance and the high-tech firms’ innovation quality.
Originality/value
Considerable literature has grown around the theme of the impact of knowledge search on the firms’ innovation quality. Nevertheless, only a few studies draw on the combination of global health emergency, cross-border knowledge search and the innovation quality; in particular, no literature has analyzed the relationship between the three from the managerial discretion perspective. Exploring the above relationships has great theoretical value for enriching and improving knowledge management and innovation management theories and provides a theoretical basis and practical support for high-tech firms to face challenges of a global health emergency and to break through the innovation dilemma.
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Abstract
Purpose
Statistical modeling has been successfully applied to integrated circuit (IC) solder joint inspection. However, there are some inherent problems in previous statistical modeling methods. This paper aims to propose an adaptive statistical modeling method to further improve the inspection performance for IC solder joints.
Design/methodology/approach
First, different pixels in the IC solder joint image were modeled by different templates, each of which was composed of the hue value of the pixel and a proposed template significance factor. Then, the potential defect image was obtained by adaptive template matching and the potential defect threshold for each pixel. It was noted that the number of templates, matching distance threshold, potential defect threshold and updating rate were adaptively updated during model training. Finally, the trained statistical model was used to inspect the IC solder joints by means of defect degree.
Findings
Experimental results indicated that the proposed adaptive schemes greatly contributed to the inspection performance of statistical modeling. Also, the proposed inspection method achieved better performance compared with some state-of-the-art inspection methods.
Originality/value
The proposed method offers a promising approach for IC solder joint inspection, which establishes different numbers of templates constructed by pixel values and template significance factors for different pixels. Also, some important parameters were adaptively updated with the updating of the model, which contributed to the inspection performance of the model.
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Yunlong Duan, Yilin Chen, Shuling Liu, Chi-Sum Wong, Meng Yang and Chang Mu
This study aims to fill the research gap on the moderating effect of leadership empowerment on the relationship between relational capital and firms' innovation performance in the…
Abstract
Purpose
This study aims to fill the research gap on the moderating effect of leadership empowerment on the relationship between relational capital and firms' innovation performance in the entrepreneurial ecosystem by addressing the following research questions: (1) How do different types of relational capital positively or negatively affect firms' innovation performance in China? (2) Does leadership empowerment play a moderating role in the above relationship?
Design/methodology/approach
Using data derived from the firms distributed in eastern, central and western China, the authors study the impact of relational capital, one of the dimensions of intellectual capital, on firms' innovation performance in the entrepreneurial ecosystem. Based on firms' operation process regarding the relationships with their external stakeholders, the authors divided relational capital into three aspects: trust, reciprocity and transparency. Furthermore, leadership empowerment is taken as the moderating variable in the above theoretical relationship.
Findings
There is significant evidence that trust, reciprocity and transparency have positive impact on firms' innovation performance. Leadership empowerment positively moderates the impact of trust and reciprocity on innovation performance. However, there is no significant moderating effect of leadership empowerment on the relationship between transparency and innovation performance.
Originality/value
In the era of the knowledge economy, the entrepreneurial ecosystem is a critical foundation for firms to improve their innovation capacity and performance, and intellectual capital is one of the most imperative drivers in terms of firms' innovation performance. Nevertheless, few studies have investigated thoroughly concerning the relationships among the entrepreneurial ecosystem, intellectual capital and innovation performance. As this study explores the relationships among the above three factors, it may have profound theoretical and practical significance for firms to extent external relationship networks, improve their innovation performance and strengthen their core competencies, which is of great significance to facilitate the construction of entrepreneurial ecosystem.
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This study aims to examine the social capital and technical determinants of knowledge adoption intentions in virtual communities and to explore the differences between posters and…
Abstract
Purpose
This study aims to examine the social capital and technical determinants of knowledge adoption intentions in virtual communities and to explore the differences between posters and lurkers.
Design/methodology/approach
An online survey was conducted with a sample of 318 virtual community participants for a structural equation model test.
Findings
The structural and cognitive social capital, peer influence, and perceived usefulness positively contribute to virtual community participants' attitudes and intentions toward knowledge adoption. Lurkers' attitudes are more influenced by network ties, reciprocity norms, shared vision, and perceived usefulness, whereas posters are more affected by social trust and shared language.
Research limitations/implications
The results produced in the Chinese context may not fully apply to other cultures.
Practical implications
Devising effective strategies to increase social capital and content value is crucial for fostering virtual community members' positive attitudes toward knowledge adoption.
Originality/value
This study is one of the first to combine and examine social capital and technology acceptance theories with regard to the knowledge adoption intentions of posters and lurkers in virtual communities.
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The purpose of this paper was to study the dyeing properties of polysulphonamide (PSA)/aramid 1313 (MPIA) blended yarn by selecting suitable dyes and carriers required in the…
Abstract
Purpose
The purpose of this paper was to study the dyeing properties of polysulphonamide (PSA)/aramid 1313 (MPIA) blended yarn by selecting suitable dyes and carriers required in the dyeing process.
Design/methodology/approach
Dyeing the blended yarn with cationic dyes, acid dyes, disperse dyes, reactive dyes and pigment, and comparing the shades, K/S values and fastness of the blended yarns.
Findings
The PSA/MPIA blended fibre is suitable for dyeing with the cationic dye at high temperature and pressure in the presence of carrier acetophenone, and good homochromatism is seen on the two fibres when using same type of dye.
Originality/value
PSA fibre is a thermo-resistant and flame-retardant product made in China in recent years. Blended with aramid 1313 fibre, it may acquire good spinnability. But there is little technical report about properties of the blended yarn in the literature at present. This paper reports the dyeing property of such fibres for the first time.
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Lei Luo, Wei Du, Songtao Wang, Weilong Wu and Xinghong Zhang
The purpose of this paper is to investigate the optimal geometry parameters in a dimple/protrusion-pin finned channel with high thermal performance.
Abstract
Purpose
The purpose of this paper is to investigate the optimal geometry parameters in a dimple/protrusion-pin finned channel with high thermal performance.
Design/methodology/approach
The BSL turbulence model is used to calculate the flow structure and heat transfer in a dimple/protrusion-pin finned channel. The optimization algorithm is set as Non-dominated Sorting Genetic Algorithm II (NSGA-II). The high Nusselt number and low friction factor are chosen as the optimization objectives. The pin fin diameter, dimple/protrusion diameter, dimple/protrusion location and dimple/protrusion depth are applied as the optimization variables. An in-house code is used to generate the geometry model and mesh. The commercial software Isight is used to perform the optimization process.
Findings
The results show that the Nusselt number and friction factor are sensitive to the geometry parameters. In a pin finned channel with a dimple, the Nusselt number is high at the rear part of the dimple, while it is low at the upstream of the dimple. A high dissipative function is found near the pin fin. In the protrusion channel, the Nusselt number is high at the leading edge of the protrusion. In addition, the protrusion induces a high pressure drop compared to the dimpled channel.
Originality/value
The originality of this paper is to optimize the geometry parameters in a pin finned channel with dimple/protrusion. This is good application for the heat transfer enhancement at the trailing side for the gas turbine.