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Article
Publication date: 16 October 2009

Pengcheng Yan, Dongqing Liu and Bo Zheng

The purpose of this paper is to forecast the reliable storage life of a certain kind of equipment under the normal stress level.

197

Abstract

Purpose

The purpose of this paper is to forecast the reliable storage life of a certain kind of equipment under the normal stress level.

Design/methodology/approach

Through the stepping stress acceleration life test and the failure mechanism analysis, this paper aims to confirm the stress level for the stepping stress acceleration life test of a certain kind of equipment and establish the data processing mathematical model and storage life forecasting method.

Findings

The stress level for the stepping stress acceleration life test of a certain kind of equipment is confirmed and the data processing mathematical model and storage life forecasting method is established.

Research limitations/implications

Availability of data is the main limitation affecting which model will be applied.

Practical implications

Useful advice for products' storage life forecasting.

Originality/value

The paper presents a new approach to product storage life estimation.

Details

Kybernetes, vol. 38 no. 10
Type: Research Article
ISSN: 0368-492X

Keywords

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Article
Publication date: 10 April 2009

Dongqing Liu, Bo Zheng and Pengcheng Yan

The purpose of this paper is to put forward a method which uses a computer to make a large number of simulated tests and determine the reference value of a system reliability…

168

Abstract

Purpose

The purpose of this paper is to put forward a method which uses a computer to make a large number of simulated tests and determine the reference value of a system reliability index according to a unit reliability index.

Design/methodology/approach

At the beginning of conducting an index demonstration and development on a new system, its unit reliability index can already reflect the unit reliability level accurately. Based on this characteristic, this index is used as the confidence lower limit of single side estimated in the unit reliability interval to find the failure distribution law of the unit. On this basis, a great number of simulated tests are made by a computer to calculate the unit failure number and reliability point estimated value every test.

Findings

The confidence lower limit of single side estimated in the system reliability interval is found by counting up the simulated test data of these units.

Research limitations/implications

Availability of data is the main limitation regarding which model will be applied.

Practical implications

A useful advice for system reliability analysis and calculation.

Originality/value

This paper presents a new approach of system reliability analysis.

Details

Kybernetes, vol. 38 no. 3/4
Type: Research Article
ISSN: 0368-492X

Keywords

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Article
Publication date: 8 January 2025

Dongqing Yu, Junjun Chen and Masoumeh Kouhsari

This study aims to examine the roles of principal resilience (psychological, social and spiritual) and trust in colleagues in predicting the flourishing of school principals…

34

Abstract

Purpose

This study aims to examine the roles of principal resilience (psychological, social and spiritual) and trust in colleagues in predicting the flourishing of school principals, considering different career stages.

Design/methodology/approach

Utilising multigroup structural equation modelling and mediation analysis, data were collected from a sample of 1,274 school principals in China. The study investigates the direct impact of resilience on flourishing and the mediating role of trust in colleagues, with a focus on variations across different career stages.

Findings

The findings reveal that all aspects of a principal’s resilience significantly impact their flourishing, with trust serving as a partial mediator. Notably, the influence of spiritual resilience on flourishing is significant only for principals in the later stages of their careers.

Originality/value

This research contributes to the expanding body of literature on educational leadership by highlighting the importance of resilience and trust in fostering principal flourishing. The insights gained offer valuable knowledge for developing support strategies to enhance the flourishing experiences of school principals throughout their careers.

Details

Journal of Educational Administration, vol. 63 no. 1
Type: Research Article
ISSN: 0957-8234

Keywords

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Article
Publication date: 16 January 2025

Sha Zhong, Mingzhi Yang, Bosen Qian, Lei Zhang, Dongqing He, Tongtong Lin and Fue-Sang Lien

This study aims to provide new insights into aerodynamic drag reduction for increasingly faster blunt-nosed trains, such as urban and freight trains. Specifically, this work…

26

Abstract

Purpose

This study aims to provide new insights into aerodynamic drag reduction for increasingly faster blunt-nosed trains, such as urban and freight trains. Specifically, this work investigates two distinctly different wake structures and associated aerodynamic drag of blunt-nosed trains.

Design/methodology/approach

Three typical cases of blunt-nosed trains with 1-, 2- and 3-m nose lengths are selected. The time-averaged and unsteady flow structures around the trains are analyzed using the improved delayed detached eddy simulation model and proper orthogonal decomposition method.

Findings

The simulation results indicate that for 2- and 3-m nose lengths, the flow separates at first and then reattaches to the slanted surface of the tail, with a pair of longitudinal vortices dominating the wake. In contrast, for the 1-m nose length case, the wake structure is characterized by complete separation, attributed to the larger curvature of the slanted tail surface. Consequently, the total time-averaged drag coefficient is reduced by 27.2% and 19.2% for the 1-m nose length case compared to the 2- and 3-m cases, respectively. Moreover, the predominant unsteady structures with Strouhal numbers St = 0.30 and St = 0.28 are detected in the near-wake of the 2- and 3-m nose length cases, respectively. These structures result from periodic vortex shedding at the lower slanted tail surface. In contrast, for the 1-m nose length case, the predominant unsteady structure with St = 0.19 is induced by the nearly periodic expansion and contraction of the upper bubbles.

Originality/value

Two distinctly different wake structures in blunt-nosed trains are identified. Unlike high-speed trains with longer, streamlined noses, for blunt-nosed trains, shorter nose lengths result in lower aerodynamic drag. Insights for reducing energy consumption in blunt-nosed trains are provided.

Details

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

Keywords

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Article
Publication date: 11 June 2021

Qinxuan Gu, Dongqing Hu and Paul Hempel

Drawing on the motivated information processing in groups (MIP-G) model, the purpose of this paper is to explore the relationship between team reward interdependence and team…

2264

Abstract

Purpose

Drawing on the motivated information processing in groups (MIP-G) model, the purpose of this paper is to explore the relationship between team reward interdependence and team performance, treating shared leadership as a mediator and team average job-based psychological ownership as a moderator.

Design/methodology/approach

Data were collected from a field sample of 72 knowledge-based work teams comprised of 466 team members and their team leaders. Data were analysed using hierarchical regression analysis and moderated path analysis.

Findings

Team reward interdependence was positively related to team performance through shared leadership. Team average job-based psychological ownership moderated both the relationship between team reward interdependence and shared leadership, and the indirect relationship between team reward interdependence and team performance.

Research limitations/implications

The shared leadership literature is extended by exploring the antecedents of shared leadership from the perspective of team incentives and by examining the moderating role of team average job-based psychological ownership.

Practical implications

Organizations and managers should pay attention to team pay system design and be aware of the importance of employees’ psychological ownership toward their jobs in promoting shared leadership in teams.

Originality/value

This study sheds light on the antecedents of shared leadership from motivated information processing perspective and examines antecedent boundary conditions through the moderating role of team average job-based psychological ownership.

Details

Personnel Review, vol. 51 no. 5
Type: Research Article
ISSN: 0048-3486

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Article
Publication date: 16 October 2009

Dongqing Zhang, Xuanxi Ning and Xueni Liu

As the conventional multistep‐ahead prediction may be unsuitable in some cases, the purpose of this paper is to propose a novel method based on joint probability distributions…

265

Abstract

Purpose

As the conventional multistep‐ahead prediction may be unsuitable in some cases, the purpose of this paper is to propose a novel method based on joint probability distributions, which provides the most probable estimation for the predicted trajectory.

Design/methodology/approach

Many real‐time series can be modeled in hidden Markov models. In order to predict these time series online, sequential Monte Carlo (SMC) method is applied for joint multistep‐ahead prediction.

Findings

The data of monthly national air passengers in China are analyzed, and the experimental results demonstrate that the method proposed and the corresponding online algorithms are effective.

Research limitations/implications

In this paper, SMC method is applied for joint multistep‐ahead prediction. However, with the increasing of prediction step, the number of particles is increasing exponentially, which means that the prediction steps cannot be too large.

Practical implications

A very useful advice for researchers who study time‐series forecasts.

Originality/value

A novel method of multistep‐ahead prediction based on joint probability distribution is proposed and SMC method is applied to prediction time series online. This paper is aimed at those researchers who focus on time‐series forecasts.

Details

Kybernetes, vol. 38 no. 10
Type: Research Article
ISSN: 0368-492X

Keywords

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Article
Publication date: 6 September 2011

Xingxing Zu, Huaming Zhou, Xiaowei Zhu and Dongqing Yao

The purpose of this study is to investigate the underlying characteristics that influence quality management implementation at manufacturing companies operating in China.

2809

Abstract

Purpose

The purpose of this study is to investigate the underlying characteristics that influence quality management implementation at manufacturing companies operating in China.

Design/methodology/approach

The data of this study were based on 199 manufacturing companies collected from a cross‐sectional survey in China. The cultural profiles of these companies were identified through cluster analysis. Multivariate analysis of variance was conducted to identify the effects of operating characteristics and cultural profile on the implementation level of quality management practices.

Findings

The results show that in general, there is no significant difference in implementing quality management practices among companies of different operating characteristics in terms of company size, industry, ownership, and production process. This study reveals that cultural profile is a distinguishing factor to explain the difference in quality management implementation among the companies.

Originality/value

As China is becoming an important supplier of products to the global market, it is necessary to understand how product quality is controlled and managed in China. This study examines the effects of operating and cultural characteristics of companies in China on their implementation of quality management practices. The results contribute to a deeper understanding of how to build an effective quality system at companies in China.

Details

International Journal of Quality & Reliability Management, vol. 28 no. 8
Type: Research Article
ISSN: 0265-671X

Keywords

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Article
Publication date: 7 June 2023

Ruyue Han, Xingmei Li, Zhong Shen and Dongqing Jia

The consideration of the substitution phenomenon in the project portfolio selection problem can improve the robustness of project portfolio selection and help enterprises better…

219

Abstract

Purpose

The consideration of the substitution phenomenon in the project portfolio selection problem can improve the robustness of project portfolio selection and help enterprises better achieve their strategic objectives. However, the existence of inter-project risk propagation will have a negative impact on project substitution. This paper proposes a new framework for project portfolio selection and constructs a risk propagation model based on strategic objectives to study the impact of risk propagation on substitution in the project portfolio.

Design/methodology/approach

The authors first construct a risk propagation model based on strategic objectives to describe the risk propagation between projects. Then the project substitution phenomenon based on risk propagation is put forward, and the calculation method of substitution loss is given. Finally, a robust project portfolio selection framework based on strategic objectives considering risk propagation is constructed.

Findings

The analysis of a case study demonstrates that (1) With the increase of risk intensity, the strategic loss of the same project portfolio increases linearly, and under the same risk intensity, the more projects in the portfolio, the stronger the robustness. (2) Considering risk propagation, the effect of project substitution is significantly weakened, and the strategic loss rate of the project portfolio is significantly increased compared with that of a direct attack.

Originality/value

This study is the first to take the project substitution into account in the project portfolio selection process. Moreover, the authors describe inter-project risk propagation and analyze the impact of risk propagation on the project substitution phenomenon. Finally, the authors extend the evaluation index of robustness. This paper puts forward a new way to solve the problem of project portfolio selection.

Details

Engineering, Construction and Architectural Management, vol. 31 no. 12
Type: Research Article
ISSN: 0969-9988

Keywords

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Article
Publication date: 28 December 2020

Zhen Zhou, Dongqing Wang and Boyang Xu

The purpose of this paper is to explore a multi-innovation with forgetting factor-based EKF-SLAM (FMI-EKF-SLAM) algorithm to solve the error increasing problem, caused by the…

320

Abstract

Purpose

The purpose of this paper is to explore a multi-innovation with forgetting factor-based EKF-SLAM (FMI-EKF-SLAM) algorithm to solve the error increasing problem, caused by the Extended Kalman filtering (EKF) violating the local linear assumption in simultaneous localization and mapping (SLAM) for mobile robots because of strong nonlinearity.

Design/methodology/approach

A multi-innovation with forgetting factor-based EKF-SLAM (FMI-EKF-SLAM) algorithm is investigated. At each filtering step, the FMI-EKF-SLAM algorithm expands the single innovation at current step to an extended multi-innovation containing current and previous steps and introduces the forgetting factor to reduce the effect of old innovations.

Findings

The simulation results show that the explored FMI-EKF-SLAM method reduces the state estimation errors, obtains the ideal filtering effect and achieves higher accuracy in positioning and mapping.

Originality/value

The method proposed in this paper improves the positioning accuracy of SLAM and improves the EKF, so that the EKF has higher accuracy and wider application range.

Details

Assembly Automation, vol. 41 no. 1
Type: Research Article
ISSN: 0144-5154

Keywords

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Article
Publication date: 12 October 2012

Dongxiao Niu, Ling Ji, Yongli Wang and Da Liu

The purpose of this paper is to improve the accuracy of short time load forecasting to ensure the economical and safe operation of power systems. The traditional neural network…

522

Abstract

Purpose

The purpose of this paper is to improve the accuracy of short time load forecasting to ensure the economical and safe operation of power systems. The traditional neural network applied in time series like load forecasting, easily plunges into local optimum and has a complicated learning process, leading to relatively slow calculating speed. On the basis of existing literature, the authors carried out studies in an effort to optimize a new recurrent neural network by wavelet analysis to solve the previous problems.

Design/methodology/approach

The main technique the authors applied is referred to as echo state network (ESN). Detailed information has been acquired by the authors using wavelet analysis. After obtaining more information from original time series, different reservoirs can be built for each subsequence. The proposed method is tested by using hourly electricity load data from a southern city in China. In addition, some traditional methods are also applied for the same task, as contrast.

Findings

The experiment has led the authors to believe that the optimized model is encouraging and performs better. Compared with standard ESN, BP network and SVM, the experimental results indicate that WS‐ESN improves the prediction accuracy and has less computing consumption.

Originality/value

The paper develops a new method for short time load forecasting. Wavelet decomposition is employed to pre‐process the original load data. The approximate part associated with low frequencies and several detailed parts associated with high frequencies components give expression to different information from original data. According to this, suitable ESN is chosen for each sub‐sequence, respectively. Therefore, the model combining the advantages of both ESN and wavelet analysis improves the result for short time load forecasting, and can be applied to other time series problem.

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