Search results
1 – 9 of 9Zhang Jinfu, Liu Wei, Qin Weiyang and He Xinsuo
A partial differential equation for elastic vibration of connecting rod of a slider‐crank mechanism is formulated by applying Theorem of Motion of Center of Mass and viscoelastic…
Abstract
A partial differential equation for elastic vibration of connecting rod of a slider‐crank mechanism is formulated by applying Theorem of Motion of Center of Mass and viscoelastic model. The partial differential equation is discretized into two second‐order ordinary differential equations by assuming a two‐mode approximation. The two equations are transformed into the first order linear ordinary differential equations with periodical coefficients. Then the stability of elastic vibration of the connecting rod is investigated using Floquet theory. Procedures for predicting the stability are developed. Finally, a case study is analyzed by applying the procedures.
Details
Keywords
Chunyu Zhang, Andreas Hirschi, Anne Herrmann, Jia Wei and Jinfu Zhang
The purpose of this paper is to test if the effects of a self-directed career attitude on career and life satisfaction are mediated by a person’s sense of calling and moderated by…
Abstract
Purpose
The purpose of this paper is to test if the effects of a self-directed career attitude on career and life satisfaction are mediated by a person’s sense of calling and moderated by job insecurity in a sample of Chinese employees.
Design/methodology/approach
Among a sample of Chinese employees (n=263), in this paper, a moderated mediation analysis with bootstrapping was applied to test the hypotheses.
Findings
The results showed that calling mediates the effects of a self-directed career attitude on career satisfaction and life satisfaction. Job insecurity moderated the effect on life satisfaction but not on career satisfaction. The effect on life satisfaction were stronger under higher levels of job insecurity.
Research limitations/implications
These results suggest that a self-directed career attitude may help people develop a calling, which in turn relates to increased subjective career success and well-being. In addition, the notion of a calling may be especially important for well-being in unstable job circumstances.
Originality/value
This study is the first to explore a calling and a self-directed career attitude in a sample of Chinese employees. Corresponding to contemporary China’s rapidly changing context of economy and career development, a self-directed career orientation plays an important role in Chinese employees’ calling and subjective career success.
Details
Keywords
Shuyan Zhao, Hao Chen, Rui Nie and Jinfu Liu
This paper aims to propose a double-sided switched reluctance linxear generator (DSRLG) exclusively for wave power generation. The initial dimensions are given through design…
Abstract
Purpose
This paper aims to propose a double-sided switched reluctance linxear generator (DSRLG) exclusively for wave power generation. The initial dimensions are given through design experience and principles. To ameliorate comprehensive performance of the DSRLG, the multi-objective optimization design is processed.
Design/methodology/approach
The multi-objective optimization design of the DSRLG is processed by adopting a modified entropy technique for order of preference by similarity to ideal solution (TOPSIS) algorithm. First, sensitivity analyzes on geometric parameters of the DSRLG are conducted to determine several pivotal geometric parameters as optimization variables. Then, the multi-objective optimization is conducted on the basis of initial dimensions. After determination of synthetical evaluation value of each structure parameter, the best dimension scheme of the DSRLG is concluded.
Findings
After verification by finite element method simulation and dynamic simulation, the final dimension scheme proves to perform better than the initial scheme. Finally, experiments are conducted to verify the accuracy of both the stable finite element DSRLG model and dynamic simulation system model so that the conclusion of this paper proves to be reliable and compelling.
Originality/value
This paper proposes an improved structure of the DSRLG, which is superior for wave power generation. Meanwhile, a novel modified entropy TOPSIS algorithm is applied to the field of electrical machine multi-objective optimal design for the first time.
Details
Keywords
Yiming Zhan, Hao Chen, Mengyu Hua, Jinfu Liu, Hao He, Patrick Wheeler, Xiaodong Li and Vitor Fernao Pires
The purpose of this paper is to achieve the multi-objective optimization design of novel tubular switched reluctance motor (TSRM).
Abstract
Purpose
The purpose of this paper is to achieve the multi-objective optimization design of novel tubular switched reluctance motor (TSRM).
Design/methodology/approach
First, the structure and initial dimensions of TSRM are obtained based on design criteria and requirements. Second, the sensitivity analysis rules, process and results of TSRM are performed. Third, three optimization objectives are determined by the average electromagnetic force, smoothing coefficient and copper loss ratio. The analytic hierarchy process-entropy method-a technique for order preference by similarity to an ideal solution-grey relation analysis comprehensive evaluation algorithm is used to optimize TSRM. Finally, a prototype is manufactured, a hardware platform is built and static and dynamic experimental validations are carried out.
Findings
The sensitivity analysis reveals that parameters significantly impact the performance of TSRM. The results of multi-objective optimization show that the average electromagnetic force and smoothing coefficient after optimization are better than before, and the copper loss ratio reduces slightly. The experimental and simulated results of TSRM are consistent, which verifies the accuracy of TSRM.
Research limitations/implications
In this paper, only three optimization objectives are selected in the multi-objective optimization process. To improve the performance of TSRM, the heating characteristics, such as iron loss, can be considered as the optimization objective for a more comprehensive analysis of TSRM performance.
Originality/value
A novel motor structure is designed, combining the advantages of the TSRM and the linear motor. The established sensitivity analysis rules are scientific and suitable for the effects of various parameters on motor performance. The proposed multi-objective optimization algorithm is a comprehensive evaluation algorithm. It considers subjective weight and objective weight and fully uses the original data and the relational degree between the optimization objectives.
Details
Keywords
This study aims to reveal the influence of milling process parameters on the surface roughness and morphology of superalloy GH4145.The groove milling mechanism and surface quality…
Abstract
Purpose
This study aims to reveal the influence of milling process parameters on the surface roughness and morphology of superalloy GH4145.The groove milling mechanism and surface quality influence factors of superalloy GH4145 were studied experimentally.
Design/methodology/approach
This paper provides investigations on three-dimensional finite element model (FEM) and simulation of milling process for GH4145.The milling experiment uses Taguchi L16 experimental design and single factor experimental design. The surface morphology of the workpiece was observed by scanning electron microscopy, and the influence mechanism of milling parameters on surface quality is expounded.
Findings
The results show that the cutting force increases by 133% with the increase in milling depth. The measured minimum surface roughness is 0.035 µm. With the change in milling depth, the surface roughness increases by 249%. With the change in cutting speed, the surface roughness increased by 54.8%. As the feed rate increases, the surface roughness increases by a maximum of 91.1%. The milling experiment verifies that the error between the predicted surface roughness and the actual value is less than 8%.
Originality/value
The milling experiment uses a Taguchi L16 experimental design and a single-factor experimental design. Mathematical models can be used in research as a contribution to current research. In addition, the milling cutter can be changed to further test this experiment. Reveal the influence of milling process parameters on the surface roughness and morphology of superalloy GH4145.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-03-2024-0080/
Details
Keywords
Jiajun Xu, Linsen Xu, Gaoxin Cheng, Jia Shi, Jinfu Liu, Xingcan Liang and Shengyao Fan
This paper aims to propose a bilateral robotic system for lower extremity hemiparesis rehabilitation. The hemiplegic patients can complete rehabilitation exercise voluntarily with…
Abstract
Purpose
This paper aims to propose a bilateral robotic system for lower extremity hemiparesis rehabilitation. The hemiplegic patients can complete rehabilitation exercise voluntarily with the assistance of the robot. The reinforcement learning is included in the robot control system, enhancing the muscle activation of the impaired limbs (ILs) efficiently with ensuring the patients’ safety.
Design/methodology/approach
A bilateral leader–follower robotic system is constructed for lower extremity hemiparesis rehabilitation, where the leader robot interacts with the healthy limb (HL) and the follow robot is worn by the IL. The therapeutic training is transferred from the HL to the IL with the assistance of the robot, and the IL follows the motion trajectory prescribed by the HL, which is called the mirror therapy. The model reference adaptive impedance control is used for the leader robot, and the reinforcement learning controller is designed for the follower robot. The reinforcement learning aims to increase the muscle activation of the IL and ensure that its motion can be mastered by the HL for safety. An asynchronous algorithm is designed by improving experience relay to run in parallel on multiple robotic platforms to reduce learning time.
Findings
Through clinical tests, the lower extremity hemiplegic patients can rehabilitate with high efficiency using the robotic system. Also, the proposed scheme outperforms other state-of-the-art methods in tracking performance, muscle activation, learning efficiency and rehabilitation efficacy.
Originality/value
Using the aimed robotic system, the lower extremity hemiplegic patients with different movement abilities can obtain better rehabilitation efficacy.
Details
Keywords
Gaoxin Cheng, Linsen Xu, Jiajun Xu, Jinfu Liu, Jia Shi, Shouqi Chen, Lei Liu, Xingcan Liang and Yang Liu
This paper aims to develop a robotic mirror therapy system for lower limb rehabilitation, which is applicable for different patients with individual movement disability levels.
Abstract
Purpose
This paper aims to develop a robotic mirror therapy system for lower limb rehabilitation, which is applicable for different patients with individual movement disability levels.
Design/methodology/approach
This paper puts forward a novel system that includes a four-degree-of-freedom sitting/lying lower limb rehabilitation robot and a wireless motion data acquisition system based on mirror therapy principle. The magnetorheological (MR) actuators are designed and manufactured, whose characteristics are detected theoretically and experimentally. The passive training control strategy is proposed, and the trajectory tracking experiments verify its feasibility. Also, the active training controller that is adapt to the human motor ability is designed and evaluated by the comparison experiments.
Findings
The MR actuators produce continuously variable and compliant torque for robotic joints by adjusting excitation current. The reference limb joint position data collected by the wireless motion data acquisition system can be used as the motion trajectory of the robot to drive the affected limb. The passive training strategy based on proportional-integral control proves to have great trajectory tracking performance through experiments. In the active training mode, by comparing the real-time parameters adjustment in two phases, it is certified that the proposed fuzzy-based regulated impedance controller can adjust assistance torque according to the motor ability of the affected limb.
Originality/value
The system developed in this paper fulfills the needs of robot-assisted mirror therapy for hemiplegic patients.
Details
Keywords
Laura Macchion, Antonella Maria Moretto, Federico Caniato, Maria Caridi, Pamela Danese and Andrea Vinelli
The purpose of this paper is to analyse whether the adoption of e-commerce improves company business, innovation and operational performance and whether sales internationalisation…
Abstract
Purpose
The purpose of this paper is to analyse whether the adoption of e-commerce improves company business, innovation and operational performance and whether sales internationalisation might moderate this relationship.
Design/methodology/approach
The research is based on a survey within the fashion industry and a multi-step linear regression model investigating the relationships between e-commerce and performance.
Findings
Results reveal that e-commerce improves innovation performance but has no significant relationship with business and operational performance. Also investigating whether the sales internationalisation might moderate the relationship between e-commerce and performance, the findings reveal that the adoption of these tools might even be negative when applied at the international level in particular by considering innovation operational practices, and the research suggests for fashion companies the necessity to develop strong markets’ knowledge and brand awareness among foreign markets and customers before investing internationally.
Originality/value
This paper offers an original analytical approach to identifying the relationships between a company’s adoption of e-commerce, performance and internationalisation within the fashion industry.
Details
Keywords
Yingwei Liu, Tao Wang, Ling Zhou and Chunyan Nie
The essence of “Chinese element” has been pinpointed as the representation of national cultural archetype resource of China, which reflects to the overall power enhancement of…
Abstract
Purpose
The essence of “Chinese element” has been pinpointed as the representation of national cultural archetype resource of China, which reflects to the overall power enhancement of China. Applying the Chinese national cultural archetype resource, which will be used for promoting the Chinese Brand internationalization, aims for the consumers' approval with the hope of integrating and spreading the unique cultural advantage of Chinese brand. The recognizing of Chinese brand's cultural archetype in this paper has constituted the basis of Chinese brand's cultural archetype strategy.
Design/methodology/approach
Based on the Grounded Theory, this paper has collected and analyzed the value symbols, character images and theme stories of Chinese narrative advertisements and constructed the cultural archetype framework of Chinese brands. This paper makes a comprehensive application of Charmaz's constructivist analysis and the main axis analysis and inspection method advocated by Strauss, with the aim of building a more objective and systematic theoretical framework for the Chinese brand cultural archetype.
Findings
In this framework, it revealed: (1) Chinese brand's cultural archetype can be divided into 12 concrete archetypes according to individual's relationship with self, the other, community and nature; (2) Consumers' different ways of self-categorization are attributed as the essential difference among various archetypes. This paper also compared and analyzed the differences between Chinese and Western cultural archetypes from three perspectives, formation of social structure, pedigree of myth and character's feature.
Originality/value
This paper has certain innovative significance to the theoretical construction of the archetype of Chinese brand culture. First, based on the cultural perspective, this paper applied the cultural psychological connotation of archetype to the brand research across culture, which is more conducive to the researchers' investigation of the cultural psychology of consumers in the cross-cultural context? Second, based on the identification and comparative study of Chinese brand culture archetype, it provides a new expansion and supplement for the research on brand internationalization and globalization in emerging countries.
Details