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Article
Publication date: 14 December 2017

Bo Xin, Yuan Li, Jian-feng Yu and Jie Zhang

The purpose of this paper is to investigate the nonlinear dynamics of the aircraft assembly lines. An approach for modeling and analyzing the production rate of an aircraft…

Abstract

Purpose

The purpose of this paper is to investigate the nonlinear dynamics of the aircraft assembly lines. An approach for modeling and analyzing the production rate of an aircraft assembly line is introduced using the chaos theory.

Design/methodology/approach

First, two key system variables including reliability and learning ability are considered to control the dynamics model. The discrete-time dynamics equation of the production rate is established as a function of the reliability and the learning rate. Then an improved Gauss-learning curve is proposed and applied to aircraft assembling condition. Finally, the bifurcation diagrams and the maximal Lyapunov exponents are used and applied to the experimental study to analyze the dynamic behavior under different combinations of parameters.

Findings

On the basis of the experimental study, it is shown that chaotic behavior really exists in the aircraft assembly lines. The reliability and the Gauss-learning curve can nonlinearly affect the production rate.

Originality/value

This paper applied nonlinear dynamics and chaotic theory to the production analyses of the aircraft assembly lines for the first time. The proposed model has been successfully applied to a practical case, and the result justifies its advantage as well as feasibility to both theory and engineering application.

Details

Assembly Automation, vol. 38 no. 1
Type: Research Article
ISSN: 0144-5154

Keywords

Content available
Article
Publication date: 23 May 2022

Tao Wang, Zheng Xie, Yuan Li, Yan Zhang, Hao Zhang and Frank Kirchner

This study aims to introduce the DoraHand, and the basic capability and performance have been verified in this paper. Besides the idea of sharing modular design and sensor design…

Abstract

Purpose

This study aims to introduce the DoraHand, and the basic capability and performance have been verified in this paper. Besides the idea of sharing modular design and sensor design, the authors want to deliver an affordable and practical dexterous hand to the research area to contribute to the robotic manipulation area.

Design/methodology/approach

This paper introduced the DoraHand, a novel scalable and practical modular dexterous hand, which, adopting modular finger and palm design, fully actuated joint and tactile sensors, can improve the dexterity for robotic manipulation and lower the complexity of maintenance. A series of experiments are delivered to verify the performance of the hand and sensor module.

Findings

The parameters of the DoraHand are verified and suitable for the research of robotics manipulation area, the sensing capability has been tested with the static experiment and the slip prediction algorithm. And, the advantage of modular design and extensible interface have been verified by the real application.

Research limitations/implications

The authors continue improving the DoraHand and extend it to more different applications. The authors want to make the DoraHand as a basic research platform in the robotic manipulation area.

Practical implications

The DoraHand has been sent to more than ten different research institutes for different research applications. The authors continue working on this hand for better performance, easier usage and more affordability.

Social implications

This kind of dexterous hand can help researchers get rid of complex physical issues and pay more attention to the algorithm part; it can help to make robotic manipulation work more popular.

Originality/value

The key design in the DoraHand is the modular finger and sensing module. With the special design in mechanical and electrical parts, the authors build reliable hardware and can support the diversity requirement in the robotic manipulation area. The hand with tactile sensing capability can be used in more research and applications with its extensibility.

Details

Industrial Robot: the international journal of robotics research and application, vol. 49 no. 4
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 15 June 2022

Yuan Li, Ruisheng Sun and Wei Chen

In this paper, an online convex optimization method for the exoatmospheric ascent trajectory of space interceptors is proposed. The purpose of this paper is to transform the…

Abstract

Purpose

In this paper, an online convex optimization method for the exoatmospheric ascent trajectory of space interceptors is proposed. The purpose of this paper is to transform the original trajectory optimization problem into a sequence of convex optimization subproblems.

Design/methodology/approach

For convenience in calculating accuracy and efficiency, the complex nonlinear terminal orbital elements constraints are converted into several quadratic equality constraints, which can be better computed by a two-step correction method during the iteration. First, the nonconvex thrust magnitude constraint is convexified by the lossless convexification technique. Then, discretization and successive linearization are introduced to transform the original problem into a sequence of one convex optimization subproblem, considering different flight phases. Parameters of trust-region and penalty are also applied to improve the computation performance. To correct the deviation in real time, the iterative guidance method is applied before orbit injection.

Findings

Numerical experiments show that the algorithm proposed in this paper has good convergence and accuracy. The successive progress can converge in a few steps and 3–4 s of CPU time. Even under engine failure or mission change, the algorithm can yield satisfactory results.

Practical implications

The convex optimization method presented in this paper is expected to generate a reliable optimal trajectory rapidly in different situations and has great potential for onboard applications of space interceptors.

Originality/value

The originality of this paper lies in the proposed online trajectory optimization method and guidance algorithm of the space inceptors, especially for onboard applications in emergency situations.

Details

Aircraft Engineering and Aerospace Technology, vol. 95 no. 1
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 28 September 2020

Yi Liu, Ting Liu, Yuan Li and Liyang Ruan

Previous studies have investigated the influence strategy–economic satisfaction links within a pairwise framework. This study aims to reexamine this issue in a network context…

Abstract

Purpose

Previous studies have investigated the influence strategy–economic satisfaction links within a pairwise framework. This study aims to reexamine this issue in a network context from both the structural and relational embeddedness perspectives.

Design/methodology/approach

An ego network approach in which the network consists of a focal distributor, other distributors and alternate manufacturers is adopted to measure the distributor’s network. Drawing on data from 124 distributors from China’s tire industry, a hierarchical multiple regression analysis is used to test the hypotheses.

Findings

The empirical results find a positive relationship between a manufacturer’s noncoercive influence strategies and the distributor’s economic satisfaction and an inverse U-shaped relationship between coercive influence strategies and economic satisfaction. It discusses the joint effects of coercive and noncoercive influence strategies and finds that the former mitigate the positive effects of the latter and that the latter flatten the inverse-U shaped effect of the former. Further, when a distributor spans rich structural holes, the effects of coercive and noncoercive influence strategies on economic satisfaction weaken. When a distributor has strong ties with its network members, the effects of noncoercive influence strategies are mitigated, while the effects of coercive influence strategies are enhanced.

Practical implications

This study provides implications for manufacturers, particularly concerning how to properly exert influence strategies to improve distributors’ economic satisfaction. Manufacturers should consider the attributes of the networks in which the distributors are embedded, involving structural holes and tie strength. They should also carefully use the two influence strategies simultaneously.

Originality/value

This study contributes to the influence strategy literature by incorporating a network perspective by empirically examining the different moderating effects of structural holes and tie strength; provides a new and powerful explanation for the effects that coercive influence strategies have on economic satisfaction by testing an inverse U-shaped effect; and examines the effects of the interaction of two strategies.

Details

Journal of Business & Industrial Marketing, vol. 37 no. 2
Type: Research Article
ISSN: 0885-8624

Keywords

Article
Publication date: 27 October 2023

Xiaodong Yuan and Fan Hou

Firms may suffer differently from the patent thickets in a particular technology field. This paper explores how patent thickets affect the financial performance of firms with…

Abstract

Purpose

Firms may suffer differently from the patent thickets in a particular technology field. This paper explores how patent thickets affect the financial performance of firms with different patent propensities and technological leadership.

Design/methodology/approach

From the perspective of patent strategy, the authors study how patent propensity, the possibility that a firm applies for patents, affects the patent thickets and financial performance. Additionally, this paper uses patent stock to measure technological leadership, the degree to which a firm can develop, maintain and enhance technology and product innovation, to study the impact of patent propensity on firms. A three-way interaction model is used to explore the relationship among patent thickets, patent propensity, technological leadership and financial performance based on an unbalanced panel of 69 Chinese telecommunication equipment firms from 2008 to 2019.

Findings

The authors find that patent propensity positively moderates patent thickets and financial performance. Notably, technological leadership negatively moderates the moderating effect of patent propensity.

Originality/value

This paper enriches the heterogeneous literature of patent thickets and financial performance. It sheds light on the fact that firms with different technological leadership may use different patent strategies to cut through patent thickets.

Details

European Journal of Innovation Management, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1460-1060

Keywords

Article
Publication date: 9 November 2023

Jianbin Luo, Yuanhao Tie, Ke Mi, Yajuan Pan, Lifei Tang, Yuan Li, Hongxiang Xu, Zhonghang Liu, Mingsen Li and Chunmei Jiang

The purpose of this paper is to investigate the optimal average drag coefficient of the Ahmed body for mixed platoon driving under crosswind and no crosswind conditions using the…

Abstract

Purpose

The purpose of this paper is to investigate the optimal average drag coefficient of the Ahmed body for mixed platoon driving under crosswind and no crosswind conditions using the response surface optimization method. This study has extraordinary implications for the planning of future intelligent transportation.

Design/methodology/approach

First, the single vehicle and vehicle platoon models are validated. Second, the configuration with the lowest average drag coefficient under the two conditions is obtained by response surface optimization. At the same time, the aerodynamic characteristics of the mixed platoon driving under different conditions are also analyzed.

Findings

The configuration with the lowest average drag coefficient under no crosswind conditions is 0.3 L for longitudinal spacing and 0.8 W for lateral spacing, with an average drag coefficient of 0.1931. The configuration with the lowest average drag coefficient under crosswind conditions is 10° for yaw angle, 0.25 L for longitudinal spacing, and 0.8 W for lateral spacing, with an average drag coefficient of 0.2251. Compared to the single vehicle, the average drag coefficients for the two conditions are reduced by 25.1% and 41.3%, respectively.

Originality/value

This paper investigates the lowest average drag coefficient for mixed platoon driving under no crosswind and crosswind conditions using a response surface optimization method. The computational fluid dynamics (CFD) results of single vehicle and vehicle platoon are compared and verified with the experimental results to ensure the reliability of this study. The research results provide theoretical reference and guidance for the planning of intelligent transportation.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 34 no. 1
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 13 February 2023

Meng Li, Li Yuan Liu, Rui Zhou, Jun Yang, Qiong Qu and Haitao Song

Considering the industrial site environment and installation requirements, the straight-beam ultrasound probe with easy installation and good coupling agent adaptability is…

Abstract

Purpose

Considering the industrial site environment and installation requirements, the straight-beam ultrasound probe with easy installation and good coupling agent adaptability is adopted to replace the traditional water immersion focusing probe for film thickness measurement in cylindrical roller bearings. The straight-beam probe has a large echo receiving range, which will result in measurement regions overlapping and bring about large measurement errors. In this paper, an improved measurement method for film thickness of cylindrical roller bearing with the straight-beam probe is developed.

Design/methodology/approach

An improved method is proposed to enhance the spatial resolution of the straight-beam probe. By introducing a correction coefficient based on the percentage of the effective measurement area, the method improves the measuring accuracy successfully.

Findings

The experimental results demonstrate that the lubricant-film thickness can be measured to reasonable accuracy by this method and have a better agreement with the theoretical film thickness solutions.

Originality/value

This paper used analytical method and model that is helpful for the improvement of the spatial resolution, which has great influence on the measuring accuracy, is mainly determined by the echo reflection area size of the ultrasound transducer.

Details

Industrial Lubrication and Tribology, vol. 75 no. 3
Type: Research Article
ISSN: 0036-8792

Keywords

Open Access
Article
Publication date: 7 May 2019

Yanan Wang, Jianqiang Li, Sun Hongbo, Yuan Li, Faheem Akhtar and Azhar Imran

Simulation is a well-known technique for using computers to imitate or simulate the operations of various kinds of real-world facilities or processes. The facility or process of…

1555

Abstract

Purpose

Simulation is a well-known technique for using computers to imitate or simulate the operations of various kinds of real-world facilities or processes. The facility or process of interest is usually called a system, and to study it scientifically, we often have to make a set of assumptions about how it works. These assumptions, which usually take the form of mathematical or logical relationships, constitute a model that is used to gain some understanding of how the corresponding system behaves, and the quality of these understandings essentially depends on the credibility of given assumptions or models, known as VV&A (verification, validation and accreditation). The main purpose of this paper is to present an in-depth theoretical review and analysis for the application of VV&A in large-scale simulations.

Design/methodology/approach

After summarizing the VV&A of related research studies, the standards, frameworks, techniques, methods and tools have been discussed according to the characteristics of large-scale simulations (such as crowd network simulations).

Findings

The contributions of this paper will be useful for both academics and practitioners for formulating VV&A in large-scale simulations (such as crowd network simulations).

Originality/value

This paper will help researchers to provide support of a recommendation for formulating VV&A in large-scale simulations (such as crowd network simulations).

Details

International Journal of Crowd Science, vol. 3 no. 1
Type: Research Article
ISSN: 2398-7294

Keywords

Article
Publication date: 6 July 2022

Xin Xia and Pengcheng Xiang

Managers of megaprojects face social risk management challenges throughout the various design, construction, and operation stages, owing to the various conflicts of interest among…

Abstract

Purpose

Managers of megaprojects face social risk management challenges throughout the various design, construction, and operation stages, owing to the various conflicts of interest among stakeholders, public skepticism, and opposition. However, most existing studies have not focused on the dynamic analysis of integrating social risks in these stages. This study developed a dynamic analysis approach to explore the dynamics of critical social risk factors and related stakeholders of megaprojects and built the managerial maps for various stakeholders.

Design/methodology/approach

Based on the social analysis network (SNA), a dynamic network analysis approach for understanding the dynamics of social risk and related stakeholders has been developed by literature and case analysis. The approach comprises the following steps: (1) generating social risk–stakeholder networks in different stages; (2) analysis of the critical stakeholders and social risk factors; (3) dynamic analysis of social risk factors; and (4) developing social risk management maps for various stakeholders. To verify the feasibility and effectiveness of the approach, 40 megaprojects from China were analyzed.

Findings

According to the results, the local government is a critical stakeholder during all stages, inadequate information promotion (IIP) and imperfect communication and coordination mechanism (ICCM) are key social risk sources throughout the megaproject life cycle. Furthermore, the management maps for government organizations, project implementation groups, and external stakeholders were constructed.

Originality/value

This research has three contributions. First, a dynamic analysis approach of stakeholder-associated social risks in megaprojects is developed, which enriches the social risk management theory of megaprojects and provides inspiration for future research focus. Second, the social risk–stakeholder networks and critical social risks in different stages are confirmed to provide a more valid and accurate picture of social risk management in megaprojects. Third, the social risk managerial maps for different stakeholders built in this research will be beneficial for governments, project implementation groups, and external stakeholders to optimize management strategies.

Details

Engineering, Construction and Architectural Management, vol. 30 no. 10
Type: Research Article
ISSN: 0969-9988

Keywords

Article
Publication date: 10 June 2021

Hyunju Shin, Jacqueline Eastman and Yuan Li

This study aims to focus on understanding the consumer-luxury brand relationships among Generation Z. Generation Z is an up-and-coming generational cohort that has received…

6021

Abstract

Purpose

This study aims to focus on understanding the consumer-luxury brand relationships among Generation Z. Generation Z is an up-and-coming generational cohort that has received limited research attention in the domains of both consumer-brand relationships and luxury branding, despite its growing size and purchasing power. Therefore, this study highlights the distinctive patterns of Generation Z’s relationship with luxury by identifying their choice of a luxury brand, the nature of the brand relationships, what characterizes these relationships and the internal and external influences that shape these relationships.

Design/methodology/approach

This study used brand collage construction. A total of 56 Generation Z respondents created brand collages that covered 38 different luxury brands. The data from the collages and their accompanying descriptions were evaluated using content analysis.

Findings

This study identifies Generation Z’s unique yet expansive view of luxury that encompasses not only traditional luxury but also masstige and non-traditional luxury brands. Moreover, the findings generally support that Generation Z’s relationships with luxury brands are characterized by “like” rather than “love”; while Generation Z may feel a high level of loyalty toward luxury brands in terms of attitudes and behaviors, they do not necessarily have strong, passionate feelings for them.

Originality/value

The findings of this study offer a comprehensive understanding of Generation Z’s brand relationship with luxury. Luxury marketers need to recognize that for Generation Z consumers, luxury is an integral part of their everyday lifestyle more than a display of success, which is clearly different from previous generations.

Details

Journal of Product & Brand Management, vol. 31 no. 3
Type: Research Article
ISSN: 1061-0421

Keywords

11 – 20 of over 9000