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Available. Open Access. Open Access
Article
Publication date: 9 May 2024

Yanhao Sun, Tao Zhang, Shuxin Ding, Zhiming Yuan and Shengliang Yang

In order to solve the problem of inaccurate calculation of index weights, subjectivity and uncertainty of index assessment in the risk assessment process, this study aims to…

330

Abstract

Purpose

In order to solve the problem of inaccurate calculation of index weights, subjectivity and uncertainty of index assessment in the risk assessment process, this study aims to propose a scientific and reasonable centralized traffic control (CTC) system risk assessment method.

Design/methodology/approach

First, system-theoretic process analysis (STPA) is used to conduct risk analysis on the CTC system and constructs risk assessment indexes based on this analysis. Then, to enhance the accuracy of weight calculation, the fuzzy analytical hierarchy process (FAHP), fuzzy decision-making trial and evaluation laboratory (FDEMATEL) and entropy weight method are employed to calculate the subjective weight, relative weight and objective weight of each index. These three types of weights are combined using game theory to obtain the combined weight for each index. To reduce subjectivity and uncertainty in the assessment process, the backward cloud generator method is utilized to obtain the numerical character (NC) of the cloud model for each index. The NCs of the indexes are then weighted to derive the comprehensive cloud for risk assessment of the CTC system. This cloud model is used to obtain the CTC system's comprehensive risk assessment. The model's similarity measurement method gauges the likeness between the comprehensive risk assessment cloud and the risk standard cloud. Finally, this process yields the risk assessment results for the CTC system.

Findings

The cloud model can handle the subjectivity and fuzziness in the risk assessment process well. The cloud model-based risk assessment method was applied to the CTC system risk assessment of a railway group and achieved good results.

Originality/value

This study provides a cloud model-based method for risk assessment of CTC systems, which accurately calculates the weight of risk indexes and uses cloud models to reduce uncertainty and subjectivity in the assessment, achieving effective risk assessment of CTC systems. It can provide a reference and theoretical basis for risk management of the CTC system.

Details

Railway Sciences, vol. 3 no. 3
Type: Research Article
ISSN: 2755-0907

Keywords

Available. Open Access. Open Access
Article
Publication date: 19 January 2024

Fuzhao Chen, Zhilei Chen, Qian Chen, Tianyang Gao, Mingyan Dai, Xiang Zhang and Lin Sun

The electromechanical brake system is leading the latest development trend in railway braking technology. The tolerance stack-up generated during the assembly and production…

477

Abstract

Purpose

The electromechanical brake system is leading the latest development trend in railway braking technology. The tolerance stack-up generated during the assembly and production process catalyzes the slight geometric dimensioning and tolerancing between the motor stator and rotor inside the electromechanical cylinder. The tolerance leads to imprecise brake control, so it is necessary to diagnose the fault of the motor in the fully assembled electromechanical brake system. This paper aims to present improved variational mode decomposition (VMD) algorithm, which endeavors to elucidate and push the boundaries of mechanical synchronicity problems within the realm of the electromechanical brake system.

Design/methodology/approach

The VMD algorithm plays a pivotal role in the preliminary phase, employing mode decomposition techniques to decompose the motor speed signals. Afterward, the error energy algorithm precision is utilized to extract abnormal features, leveraging the practical intrinsic mode functions, eliminating extraneous noise and enhancing the signal’s fidelity. This refined signal then becomes the basis for fault analysis. In the analytical step, the cepstrum is employed to calculate the formant and envelope of the reconstructed signal. By scrutinizing the formant and envelope, the fault point within the electromechanical brake system is precisely identified, contributing to a sophisticated and accurate fault diagnosis.

Findings

This paper innovatively uses the VMD algorithm for the modal decomposition of electromechanical brake (EMB) motor speed signals and combines it with the error energy algorithm to achieve abnormal feature extraction. The signal is reconstructed according to the effective intrinsic mode functions (IMFS) component of removing noise, and the formant and envelope are calculated by cepstrum to locate the fault point. Experiments show that the empirical mode decomposition (EMD) algorithm can effectively decompose the original speed signal. After feature extraction, signal enhancement and fault identification, the motor mechanical fault point can be accurately located. This fault diagnosis method is an effective fault diagnosis algorithm suitable for EMB systems.

Originality/value

By using this improved VMD algorithm, the electromechanical brake system can precisely identify the rotational anomaly of the motor. This method can offer an online diagnosis analysis function during operation and contribute to an automated factory inspection strategy while parts are assembled. Compared with the conventional motor diagnosis method, this improved VMD algorithm can eliminate the need for additional acceleration sensors and save hardware costs. Moreover, the accumulation of online detection functions helps improve the reliability of train electromechanical braking systems.

Available. Content available
Book part
Publication date: 14 December 2023

Filippo Marchesani

Free Access. Free Access

Abstract

Details

The Global Smart City
Type: Book
ISBN: 978-1-83797-576-1

Available. Content available
Article
Publication date: 7 September 2015

George Stylios

202

Abstract

Details

International Journal of Clothing Science and Technology, vol. 27 no. 5
Type: Research Article
ISSN: 0955-6222

Available. Content available
Book part
Publication date: 7 October 2024

Free Access. Free Access

Abstract

Details

The Mediating Power of Sport
Type: Book
ISBN: 978-1-83753-079-3

Available. Content available
Article
Publication date: 22 July 2024

Jiyoon An

This paper summarizes and synthesizes existing research while critically assessing findings for future studies to advance the scholarship of maritime logistics and digital…

670

Abstract

Purpose

This paper summarizes and synthesizes existing research while critically assessing findings for future studies to advance the scholarship of maritime logistics and digital transformation with big data.

Design/methodology/approach

A bibliometric analysis was conducted on 159 journal articles from the Scopus database with search keywords “maritime*” and “big data.” This analysis helps identify research gaps by identifying themes via keyword co-occurrence, co-citation and bibliographic coupling analysis. The Theory-Context-Characteristics-Methodology (TCCM) framework was applied to understand the findings of bibliometric analysis and provide a research agenda.

Findings

The analyses identified emerging themes of the scholarship of maritime logistics and digital transformation with big data and their relationships to identify research clusters. Future research directions were provided by examining existing research's theory, context, characteristics and method.

Originality/value

This research is grounded in bibliometric analysis and the TCCM framework to understand the scholarly evolution, giving managers and academics retrospective and prospective insights.

Details

Maritime Business Review, vol. 9 no. 3
Type: Research Article
ISSN: 2397-3757

Keywords

Available. Open Access. Open Access
Article
Publication date: 14 June 2023

Fangxuan (Sam) Li

Souvenirs have been repeatedly studied as both a subject and as a variable for other tourism-related phenomena, but research into this issue is fragmented. The purpose of this…

7719

Abstract

Purpose

Souvenirs have been repeatedly studied as both a subject and as a variable for other tourism-related phenomena, but research into this issue is fragmented. The purpose of this study is twofold: first, to analyze souvenir in tourism to provide a comprehensive state-of-the-art review. Second, this paper contributes to identifying the directions for future search through reviewing existing literature. This study is one of the first papers to offer a systematic overview of the key themes in tourism souvenir research. In addition to the key themes, this paper also offers insights into future souvenir research.

Details

Tourism Critiques: Practice and Theory, vol. 4 no. 1/2
Type: Research Article
ISSN: 2633-1225

Keywords

Available. Content available
Article
Publication date: 4 December 2017

Samantha Chaperon

1573

Abstract

Details

International Journal of Tourism Cities, vol. 3 no. 4
Type: Research Article
ISSN: 2056-5607

Available. Open Access. Open Access
Article
Publication date: 7 May 2024

Giovanna Culot, Matteo Podrecca and Guido Nassimbeni

This study analyzes the performance implications of adopting blockchain to support supply chain business processes. The technology holds as many promises as implementation…

1784

Abstract

Purpose

This study analyzes the performance implications of adopting blockchain to support supply chain business processes. The technology holds as many promises as implementation challenges, so interest in its impact on operational performance has grown steadily over the last few years.

Design/methodology/approach

Drawing on transaction cost economics and the contingency theory, we built a set of hypotheses. These were tested through a long-term event study and an ordinary least squares regression involving 130 adopters listed in North America.

Findings

Compared with the control sample, adopters displayed significant abnormal performance in terms of labor productivity, operating cycle and profitability, whereas sales appeared unaffected. Firms in regulated settings and closer to the end customer showed more positive effects. Neither industry-level competition nor the early involvement of a project partner emerged as relevant contextual factors.

Originality/value

This research presents the first extensive analysis of operational performance based on objective measures. In contrast to previous studies and theoretical predictions, the results indicate that blockchain adoption is not associated with sales improvement. This can be explained considering that secure data storage and sharing do not guarantee the factual credibility of recorded data, which needs to be proved to customers in alternative ways. Conversely, improvements in other operational performance dimensions confirm that blockchain can support inter-organizational transactions more efficiently. The results are relevant in times when, following hype, there are signs of disengagement with the technology.

Details

International Journal of Operations & Production Management, vol. 44 no. 13
Type: Research Article
ISSN: 0144-3577

Keywords

Available. Open Access. Open Access
Article
Publication date: 22 November 2024

Feng Zhao, Jianbao Zhang and Zhen Luo

The correlations and deviations between market prices, production prices and values are critical indexes for testing the labor theory of value. However, there is not yet a…

103

Abstract

Purpose

The correlations and deviations between market prices, production prices and values are critical indexes for testing the labor theory of value. However, there is not yet a universally accepted method of solving for the production price vector, and given the complexity and volatility of economic dynamics, production prices based on the assumption of economic equilibrium cannot be accurate measuring. This paper attempts to propose a new approach to test the labor theory of value.

Design/methodology/approach

This paper proposes a different approach. From the perspective of disequilibrium price, the paper deduces that the range of the relative prices of commodities is determined by the relative value, the rate of surplus-value and the technical structure of production inputs, with relative price fluctuating within the value range specified by the labor theory of value under market competition influences.

Findings

With empirical research results based on China’s economic data, this paper not only affirms the scientific and practical explanatory power of the labor theory of value in a more general sense but also uncovers how surplus value is distributed across sectors, which can be used to analyze market competition and technical relations and their impacts on industrial structure and distribution.

Originality/value

The disequilibrium analytical framework provides a new perspective for the empirical study of labor theory of value. Moreover, it evolves the labor theory of value into a robust empirical framework, breaking through the theoretical path of the traditional labor theory of value that is mostly limited to the normative discussion of exploitation.

Details

China Political Economy, vol. 7 no. 1
Type: Research Article
ISSN: 2516-1652

Keywords

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