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Available. Open Access. Open Access
Article
Publication date: 24 November 2022

Zhou Shi, Jiachang Gu, Yongcong Zhou and Ying Zhang

This study aims to research the development trend, research status, research results and existing problems of the steel–concrete composite joint of railway long-span hybrid girder…

626

Abstract

Purpose

This study aims to research the development trend, research status, research results and existing problems of the steel–concrete composite joint of railway long-span hybrid girder cable-stayed bridge.

Design/methodology/approach

Based on the investigation and analysis of the development history, structure form, structural parameters, stress characteristics, shear connector stress state, force transmission mechanism, and fatigue performance, aiming at the steel–concrete composite joint of railway long-span hybrid girder cable-stayed bridge, the development trend, research status, research results and existing problems are expounded.

Findings

The shear-compression composite joint has become the main form in practice, featuring shortened length and simplified structure. The length of composite joints between 1.5 and 3.0 m has no significant effect on the stress and force transmission laws of the main girder. The reasonable thickness of the bearing plate is 40–70 mm. The calculation theory and simplified calculation formula of the overall bearing capacity, the nonuniformity and distribution laws of the shear connector, the force transferring ratio of steel and concrete components, the fatigue failure mechanism and structural parameters effects are the focus of the research study.

Originality/value

This study puts forward some suggestions and prospects for the structural design and theoretical research of the steel–concrete composite joint of railway long-span hybrid girder cable-stayed bridge.

Details

Railway Sciences, vol. 1 no. 2
Type: Research Article
ISSN: 2755-0907

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Article
Publication date: 5 February 2018

Ai Yue, Bin Tang, Yaojiang Shi, Jingjing Tang, Guanminjia Shang, Alexis Medina and Scott Rozelle

The purpose of this paper is to describe the policy and trends in rural education in China over the past 40 years; and also discuss a number of challenges that are faced by…

2237

Abstract

Purpose

The purpose of this paper is to describe the policy and trends in rural education in China over the past 40 years; and also discuss a number of challenges that are faced by China’s rural school system.

Design/methodology/approach

The authors use secondary data on policies and trends over the past 40 years for preschool, primary/junior high school, and high school.

Findings

The trends over the past 40 years in all areas of rural schooling have been continually upward and strong. While only a low share of rural children attended preschool in the 1980s, by 2014 more than 90 percent of rural children were attending. The biggest achievement in compulsory education is that the rise in the number of primary students that finish grade 6 and matriculate to junior high school. There also was a steep rise of those going to and completing high school. While the successes in upscaling rural education are absolutely unprecedented, there are still challenges.

Research limitations/implications

This is descriptive analysis and there is not causal link established between policies and rural schooling outcomes.

Practical implications

The authors illustrate one of the most rapid rises of rural education in history and match the achievements up with the policy efforts of the government. The authors also explore policy priorities that will be needed in the coming years to raise the quality of schooling.

Originality/value

This is the first paper that documents both the policies and the empirical trends of the success that China has created in building rural education from preschool to high school during the first 40 years of reform (1978-2018). The paper also documents – drawing on the literature and the own research – the achievements and challenges that China still face in the coming years, including issues of gender, urbanization, early childhood education and health and nutrition of students.

Details

China Agricultural Economic Review, vol. 10 no. 1
Type: Research Article
ISSN: 1756-137X

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Article
Publication date: 17 August 2021

Bin Zhou, Jin Ma, Hongyan Zhou, Xiaoliang Shi and Ahmed Mohamed Mahmoud Ibrahim

This paper aims to investigate the friction noise properties of M50 matrix curved microporous channel composites filled with solid lubricant Sn-Ag-Cu (MS).

101

Abstract

Purpose

This paper aims to investigate the friction noise properties of M50 matrix curved microporous channel composites filled with solid lubricant Sn-Ag-Cu (MS).

Design/methodology/approach

Pure M50 (MA) and MS are prepared by selective laser melting and vacuum-pressure infiltration technology. The tribological and friction noise properties of MA and MS are tested through dry sliding friction and then the influential mechanism of surface wear sate on friction noise is investigated by analyzing the variation law of noise signals and the worn surface characteristics of MS.

Findings

Experimental results show that the friction noise sound pressure level of MS is only 75.6 dB, and it mainly consists of low-frequency noise. The Sn-Ag-Cu improves the surface wear state, which reduces self-excited vibration of the interface caused by fluctuation of friction force, leading to the decrease of friction noise.

Originality/value

This investigation is meaningful to improve the tribological property and suppress the friction noise of M50 bearing steel.

Details

Industrial Lubrication and Tribology, vol. 73 no. 6
Type: Research Article
ISSN: 0036-8792

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Book part
Publication date: 2 June 2015

Jaclyn Koopmann, Mo Wang, Yihao Liu and Yifan Song

In this chapter, we summarize and build on the current state of the customer mistreatment literature in an effort to further future research on this topic. First, we detail the…

Abstract

In this chapter, we summarize and build on the current state of the customer mistreatment literature in an effort to further future research on this topic. First, we detail the four primary conceptualizations of customer mistreatment. Second, we present a multilevel model of customer mistreatment, which distinguishes between the unfolding processes at the individual employee level and the service encounter level. In particular, we consider the antecedents and outcomes unique to each level of analysis as well as mediators and moderators. Finally, we discuss important methodological concerns and recommendations for future research.

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Book part
Publication date: 8 December 2021

Qiang Pan-Hammarström

Abstract

Details

Globalization, Political Economy, Business and Society in Pandemic Times
Type: Book
ISBN: 978-1-80071-792-3

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Article
Publication date: 11 October 2022

Shi Zhou, Jia Zhao, Yi Shan Shi, Yi Fan Wang and Shun Qi Mei

In the fabric manufacturing industry, various unfavorable factors, including machine fault and yarn breakage, can easily cause fabric defects and affect product quality, begetting…

358

Abstract

Purpose

In the fabric manufacturing industry, various unfavorable factors, including machine fault and yarn breakage, can easily cause fabric defects and affect product quality, begetting huge economic losses to enterprises. Thus, automatic fabric defect detection systems have become an important development direction. Herein, the most common defects in the fabric production process, like ribbon yarn, broken yarn, cotton ball, holes, yarn shedding and stains, are detected. Current fabric defect detection systems afford low detection accuracy and a high missed detection rate for small target fabric defects. Therefore, this study proposes deep learning technology for automatically detecting fabric defects by improving the YOLOv5s target detection algorithm. The improved algorithm is termed YOLOv5s-4SCK, which can effectively detect fabric defects. This study aims to discuss the aforementioned issues.

Design/methodology/approach

Specifically, based on the YOLOv5s algorithm, first, the structure of YOLOv5s is modified to add a small target detection layer, fully utilize deep and shallow features and reduce the missed detection rate of small target fabric defects. Second, the integration of CARAFE upsampling enables the effective retention of feature information and maintenance of a certain computational efficiency, thereby improving the detection accuracy. Finally, the K-Means++ clustering algorithm is used to analyze the position of the center point of the prior box to better obtain the anchor box and improve the average accuracy and evaluation index of detection.

Findings

The research results show that the YOLOv5s-4SCK algorithm increases the accuracy by 4.1% and the detection speed by 2 f.s-1 compared to the original YOLOv5s algorithm, and it effectively improves the original YOLOv5s problem of high missed detection rate of small targets.

Research limitations/implications

The YOLOv5s-4SCK proposed in this paper can effectively reduce the missed detection rate of fabric defects, improve the detection efficiency and has certain industrial value.

Practical implications

The proposed algorithm can quickly identify fabric defects, effectively improving the detection rate. In the future, the proposed algorithm will be applied in the actual industry.

Social implications

Automatic fabric defect detection reduces the manpower of inspectors, and the proposed YOLOv5s-4SCK algorithm is also suitable for other recognition fields.

Originality/value

The proposed YOLOv5s-4SCK algorithm has been tested using real cloth to ensure its accuracy, and its performance is better than the original YOLOv5s algorithm.

Details

International Journal of Clothing Science and Technology, vol. 35 no. 1
Type: Research Article
ISSN: 0955-6222

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Article
Publication date: 25 July 2019

Yinhua Liu, Rui Sun and Sun Jin

Driven by the development in sensing techniques and information and communications technology, and their applications in the manufacturing system, data-driven quality control…

663

Abstract

Purpose

Driven by the development in sensing techniques and information and communications technology, and their applications in the manufacturing system, data-driven quality control methods play an essential role in the quality improvement of assembly products. This paper aims to review the development of data-driven modeling methods for process monitoring and fault diagnosis in multi-station assembly systems. Furthermore, the authors discuss the applications of the methods proposed and present suggestions for future studies in data mining for quality control in product assembly.

Design/methodology/approach

This paper provides an outline of data-driven process monitoring and fault diagnosis methods for reduction in variation. The development of statistical process monitoring techniques and diagnosis methods, such as pattern matching, estimation-based analysis and artificial intelligence-based diagnostics, is introduced.

Findings

A classification structure for data-driven process control techniques and the limitations of their applications in multi-station assembly processes are discussed. From the perspective of the engineering requirements of real, dynamic, nonlinear and uncertain assembly systems, future trends in sensing system location, data mining and data fusion techniques for variation reduction are suggested.

Originality/value

This paper reveals the development of process monitoring and fault diagnosis techniques, and their applications in variation reduction in multi-station assembly.

Details

Assembly Automation, vol. 39 no. 4
Type: Research Article
ISSN: 0144-5154

Keywords

Available. Open Access. Open Access
Article
Publication date: 19 May 2022

Feng Shi, Xian Tu and Shuo Zhao

Under the constraints of given passenger service level and coupling travel demand with train departure time, this study optimizes the train operational plan in an urban rail…

645

Abstract

Purpose

Under the constraints of given passenger service level and coupling travel demand with train departure time, this study optimizes the train operational plan in an urban rail corridor to minimize the numbers of train trips and rolling stocks considering the time-varying demand of urban rail passenger flow.

Design/methodology/approach

The authors optimize the train operational plan in a special network layout, i.e. an urban rail corridor with dead-end terminal yard, by decomposing it into two sub-problems: train timetable optimization and rolling stock circulation optimization. As for train timetable optimization, the authors propose a schedule-based passenger flow assignment method, construct the corresponding timetabling optimization model and design the bi-directional coordinated sequential optimization algorithm. For the optimization of rolling stock circulation, the authors construct the corresponding optimization assignment model and adopt the Hungary algorithm for solving the model.

Findings

The case study shows that the train operational plan developed by the study's approach meets requirements on the passenger service quality and reduces the operational cost to the maximum by minimizing the numbers of train trips and rolling stocks.

Originality/value

The example verifies the efficiency of the model and algorithm.

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Article
Publication date: 5 March 2018

Ling Zhou, Ling Bai, Wei Li, Weidong Shi and Chuan Wang

The purpose of this study is to validate the different turbulence models using in the numerical simulation of centrifugal pump diffuser. Computational fluid dynamics (CFD) has…

410

Abstract

Purpose

The purpose of this study is to validate the different turbulence models using in the numerical simulation of centrifugal pump diffuser. Computational fluid dynamics (CFD) has become the main method to study the pump inner flow patterns. It is important to understand the differences and features of the different turbulence models used in turbomachinery.

Design/methodology/approach

The velocity flow fields in a compact return diffuser under different flow conditions are studied and compared between CFD and particle image velocimetry (PIV) measurements. Three turbulence models are used to solve the steady flow field using high-quality fine structured grids, including shear stress transport (SST) k-w model, detached-eddy simulation (DES) model and SST k-w model with low-Re corrections.

Findings

SST k-w model with low-Re correction gives better results compared to DES and SST k-w model, and gives a good predication about the vortex core position under strong part-loading conditions.

Originality/value

A special test rig is designed to carry out the 2D PIV measurements under high rotating speed of 2850 r/min, and the PIV results are used to validate the CFD results.

Details

Engineering Computations, vol. 35 no. 1
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 18 October 2018

Shi Zhou and Masoud Gheisari

Over the past decade, researchers have used unmanned aerial systems (UASs) in construction industry for various applications from site inspection to safety monitoring or building…

1692

Abstract

Purpose

Over the past decade, researchers have used unmanned aerial systems (UASs) in construction industry for various applications from site inspection to safety monitoring or building maintenance. This paper aims to assort academic studies on construction UAS applications, summarize logics behind using UAS in each application and extend understanding of current state of UAS research in the construction setting.

Design/methodology/approach

This research follows a systematic literature assessment methodology to summarize the results of 54 research papers over the past ten years and outlines the research trends for applying UASs in construction.

Findings

UASs are used in building inspection, damage assessment, site surveying, safety inspection, progress monitoring, building maintenance and other construction applications. Cost saving, time efficiency and improved accessibility are the primary reasons for choosing UAS in construction applications. Rotary-wing UASs are the most common types of UASs being used in construction. Cameras, LiDAR and Kinect are the most common onboard sensors integrated in construction UAS applications. The control styles used are manual, semi-autonomous and autonomous.

Originality/value

This paper contributes to classification of UAS applications in construction research and identification of UAS hardware and sensor types as well as their flying control systems in construction literature.

Details

Construction Innovation, vol. 18 no. 4
Type: Research Article
ISSN: 1471-4175

Keywords

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