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Article
Publication date: 17 August 2021

Chengxi Zhang, Hui-Jie Sun, Jin Wu, Zhongyang Fei, Yu Jiang and Guanhua Zhang

This paper aims to study the attitude control problem with mutating orbital rate and actuator fading.

Abstract

Purpose

This paper aims to study the attitude control problem with mutating orbital rate and actuator fading.

Design/methodology/approach

To avoid malicious physical attacks and hide itself, the spacecraft may irregularly switch its orbit altitude within a specific range, which will bring about variations in orbital rate, thereby causing mutations in the attitude dynamics model. The actuator faults will also cause changes in system dynamics. Both factors affect the control performance. First, this paper determines the potential switching orbits. Then under different conditions, design controllers that can accommodate actuator faults according to the statistical law of actuator fading.

Findings

This paper, to the best of the authors’ knowledge, for the first time, introduces the Markovian jump framework to model the possible unexpected mutating of orbital rate and actuator fading of spacecraft and then designs a novel control policy to solve the attitude control problem.

Practical implications

This paper also provides the algorithm design processes in detail. A comparative numerical simulation is given to verify the effectiveness of the proposed algorithm.

Originality/value

This is an early solution for spacecraft attitude control with dynamics model mutations.

Details

Aircraft Engineering and Aerospace Technology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1748-8842

Keywords

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Article
Publication date: 19 March 2021

Chengxi Zhang, Jin Wu, Yulong Huang, Yu Jiang, Ming-zhe Dai and Mingjiang Wang

Recent spacecraft attitude control systems tend to use wireless communication for cost-saving and distributed mission purposes while encountering limited communication…

Abstract

Purpose

Recent spacecraft attitude control systems tend to use wireless communication for cost-saving and distributed mission purposes while encountering limited communication resources and data exposure issues. This paper aims to study the attitude control problem with low communication frequency under the sampled-data.

Design/methodology/approach

The authors propose constructive control system structures based on quantization and event-triggered methods for intra-spacecraft and multi-spacecraft systems, and they also provide potential solutions to shield the control system's data security. The proposed control architectures can effectively save communication resources for both intra-spacecraft and multi-spacecraft systems.

Findings

The proposed control architectures no longer require sensors with trigger-ing mechanism and can achieve distributed control schemes. This paper also provides proposals of employing the public key encryption to secure the data in control-loop, which is transmitted by the event-triggered control mechanism.

Practical implications

Spacecraft attempts to use wireless communication, yet the attitude control system does not follow up promptly to accommodate these variations. Compared with existing approaches, the proposed control structures can save communication resources of control-loop in multi-sections effectively, and systematically, by rationally configuring the location of quantization and event-triggered mechanisms.

Originality/value

This paper presents several new control schemes and a necessary condition for the employment of encryption algorithms for control systems based on event-based communication.

Details

Aircraft Engineering and Aerospace Technology, vol. 93 no. 2
Type: Research Article
ISSN: 1748-8842

Keywords

Content available
Article
Publication date: 13 December 2019

Xinhua Jian and Jiang Yu

The purpose of this paper is to review the four large and two small fluctuations in China’s economic growth since the reform and opening up, which can be further divided…

Abstract

Purpose

The purpose of this paper is to review the four large and two small fluctuations in China’s economic growth since the reform and opening up, which can be further divided into five periods of economic upturn and six periods of economic downturn.

Design/methodology/approach

This paper also analyzes the performance, causes and practical countermeasures of these fluctuations and summarizes the experience and lessons from the eight aspects of dealing with economic downturn and stabilizing growth since the reform and opening up.

Findings

At last, the paper puts forward some measures to cope with economic downturn and stabilize growth under the new normal in the new era.

Originality/value

Any country’s economic growth is a tortuous process with many fluctuations. The rate of economic growth cannot rise or go down straight for a long time, and China’s economic growth is no exception. The drastic fluctuations of economic growth can lead to serious overproduction, waste of resources, increased unemployment, decreased income or supply shortages, rising prices and decline of living standards.

Details

China Political Economy, vol. 2 no. 2
Type: Research Article
ISSN: 2516-1652

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Article
Publication date: 2 July 2020

Yu Jiang, Mingjun Li and Panpan Xia

Banking is the key industry to guarantee the core leading role of finance in the process of economic development. It is important to study the bank efficiency and optimal…

Abstract

Purpose

Banking is the key industry to guarantee the core leading role of finance in the process of economic development. It is important to study the bank efficiency and optimal allocation of bank’s resources. The purpose of our paper is to study the optimal allocation of resources between the bank savings system and loan system under the premise of environmental heterogeneity.

Design/methodology/approach

We use a two-stage meta-frontier Data Envelopment Analysis model to solve the relative efficiency of each city branch and use the multivariate statistical tools to analyze the empirical results.

Findings

This paper measures the relative efficiency of 16 Bank Branches of a state-owned bank in Anhui province considering regional heterogeneity. Based on the optimal resource allocation, we get the two-stage operation performance of all banks under group-frontier and meta-frontier and analyze the impact of the technical differences between the branches.

Originality/value

This study has a positive guiding significance for the banking industry to improve its operational efficiency in various business practices in the new era of big data. It will also provide practical suggestions and support for the government and relevant departments in the process of formulating macro-policies to ensure the healthy and stable development of the banking industry.

Details

Industrial Management & Data Systems, vol. 121 no. 4
Type: Research Article
ISSN: 0263-5577

Keywords

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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.

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

Abstract

Details

Applying Partial Least Squares in Tourism and Hospitality Research
Type: Book
ISBN: 978-1-78756-700-9

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Book part
Publication date: 2 August 2021

Jun Teng and Na An

With the rapid development of the Chinese economy and society, the number of international schools in China has increased sharply. As a core part of school quality, the…

Abstract

With the rapid development of the Chinese economy and society, the number of international schools in China has increased sharply. As a core part of school quality, the curriculum development in international schools is facing a series of challenges due to the changing requirements from both the government and the market. In order to better understand the current practices of curriculum development in these international schools in China, this study adopts Tyler’s and Gu’s curriculum theories to design a questionnaire to collect data from 104 international schools national-wide. In addition, a semi-structured interview for teachers and principals was also conducted in nine international schools in five different cities in China.

The findings show that most international schools aim at cultivating “global citizens” or “leaders and elites.” In China, most schools attach importance to foreign language teaching, and most courses are offered in English. Group work, inquiry and discussion, and project-based learning are frequently adopted in international schools. The findings also show there is a strong integration of “Chinese culture” and “global vision,” and schools generally try to balance the two aspects. Some schools rely heavily on foreign curriculum resources, and are in urgent need of capacity building in term of curriculum development based on Chinese policy, market demands and their school realities. Compared with developed countries, international schools in China endorse the new mission, mixing the requirements of modernization and globalization at the same time. Therefore, how to reconstruct a Chinese neo-modern curriculum system is the fundamental challenge for all international schools in China.

Details

Annual Review of Comparative and International Education 2020
Type: Book
ISBN: 978-1-80071-907-1

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Article
Publication date: 7 September 2015

Yumiao Chen, Jianping Wang and Zhongliang Yang

– The purpose of this paper is to provide an overview of the human factors/ergonomics (HFE) studies for respirator.

Abstract

Purpose

The purpose of this paper is to provide an overview of the human factors/ergonomics (HFE) studies for respirator.

Design/methodology/approach

This review paper describes and discusses the various factors and methodologies of HFE, for the purpose of better considering human factors, used in respirator studies and further human-centered product development.

Findings

Many attempts have been made to study human factors for respirators mainly including fit, human performance, comfort, and mood. Physical, psychological, and physiological indices of people are extremely valuable to HFE studies for respirator. Objective and subjective measures were methodologies widely used. Quantitative and qualitative approaches were adopted to illustrate the human performance and well-being influenced by respirators. A summary table presented with major methods used for indices of respirators in the field of HFE. According to the current researches, this review indicated three particular challenges facing HFE studies of respirators now.

Practical implications

With the ever increasing role of protection from air pollution in society, respirator has become an increasingly important part of our daily lives. HFE intervene in optimizing the relationships between respirators and the human using them. Plenty of efforts have been dedicated for the development of protection capability, but HFE studies for respirators are lacking. In recent years, there has been a tremendous interest in introducing HFE research methods that can evaluate respirators from the perspective of human and translate them into constraints for designing human-centered respirators.

Originality/value

This is a first paper in the field of HFE studies for respirator, which will remain helpful to the scientific community to start further human-centered research work and product development.

Details

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

Keywords

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Article
Publication date: 21 June 2021

Rômulo Marcos Lardosa Rebelo, Susana Carla Farias Pereira and Maciel M. Queiroz

This study aims to identify and analyze how Internet of things (IoT) technology affects supply chain management (SCM) performance.

Abstract

Purpose

This study aims to identify and analyze how Internet of things (IoT) technology affects supply chain management (SCM) performance.

Design/methodology/approach

A systematic literature review was conducted (using Scopus, JSTOR, Emerald, ProQuest, Science Direct and Web of Science) covering a 20-year timeframe (2000–2020). Out of 2,572 papers identified, 171 peer-reviewed papers from the most important journals were selected. Content analysis was used following the Global Supply Chain Forum (GSCF) SCM framework.

Findings

Regarding the GSCF SCM framework processes, most IoT-based studies have addressed improving order fulfilment, manufacturing flow management and demand management processes. However, no studies addressing the Supplier relationship management process were identified, suggesting that IoT-based applications are perceived to add more value in downstream than upstream SCM processes. The importance of using enabling technologies to realize the potential of value generation of IoT was also revealed. Findings suggest new research avenues related to product development and commercialization process, the supplier relationship management process, the returns management process, servitization strategies, new SCM models and new business models.

Research limitations/implications

The review encompasses only academic papers from journals considered the most relevant (retrieved from specific databases), using the impact factor as the quality criterion.

Practical implications

The findings can help business managers better understand the potential of IoT technology, such as the main applications identified in the literature and their impacts on SCM processes. Their importance in enabling technologies to leverage SCM performance is identified and the emerging SCM models/business models that IoT deployment can enable are highlighted.

Originality/value

This study contributes to filling a gap in the literature using a systematic literature review of how IoT technology affects SCM performance through content analysis, using an SCM framework to clarify which SCM processes are affected. Academic articles from the most important journals from 2000 to 2020 are identified.

Details

Benchmarking: An International Journal, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1463-5771

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Article
Publication date: 25 October 2019

Hossine Guermit, Katia Kouzi and Sid Ahmed Bessedik

This paper aims to present a contribution to improve the performance of vector control scheme of double star induction motor drive (DSIM) by using an optimized synergetic…

Abstract

Purpose

This paper aims to present a contribution to improve the performance of vector control scheme of double star induction motor drive (DSIM) by using an optimized synergetic control approach. The main advantage of synergetic control is that it supports all parametric and nonparametric uncertainties, which is not the case in several control strategies.

Design/methodology/approach

The suggested controller is developed based on the synergistic control theory and the particle swarm optimization (PSO) algorithm which allow to obtain the optimal parameter of suggested controller to improve the performance of control system.

Findings

To show the benefits of proposed controller, a comparative simulation results between conventional PI controller, sliding mode controller and suggested controller were carried out.

Originality/value

The obtained simulation results illustrate clearly that synergetic controller ensures a rapid response, asymptotic stability of the closed-loop system in the all range operating condition and system robustness in presence of parameter variation in all range of operating conditions.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering , vol. 38 no. 6
Type: Research Article
ISSN: 0332-1649

Keywords

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