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Article
Publication date: 21 August 2018

Bo Li, Bo Yuan, Shuai Tang, Yuwen Mao, Dongmei Zhang, Changyun Huang and Bilian Tan

This paper aims to investigate weight-climbing assistance strategy for the biomechanical design of passive knee-assisting exoskeleton (PKAExo) and evaluate a designed PKAExo which…

579

Abstract

Purpose

This paper aims to investigate weight-climbing assistance strategy for the biomechanical design of passive knee-assisting exoskeleton (PKAExo) and evaluate a designed PKAExo which stores energy when the knee joint flexes and releases the energy to assist ascending when the knee joint extends.

Design/methodology/approach

The authors constructed theoretic modeling of human weight-climbing to analyze characteristics of knee angle and moment. They then conducted camera-based movement analysis, muscle strength and endurance tests and surface electromyography (sEMG) measures to verify the relationship of knee angle and moment with both stair height and load weight. Afterwards, the authors proposed an assistant strategy for passive knee assistance, then gave out designed PKAExo and conducted mechanical experiment to test the knee-assisting torque. Finally, the authors conducted comparison experiment based on measuring the sEMG signals of knee extensor to verify the assistance effect of the PKAExo for weight-climbing.

Findings

The knee extensor produces the maximum force during weight-climbing, and the muscle force provided by knee extensor has significant increasing rate along with the stair height. Thus, the assistance torque of PKAExo is designed to increase nonlinearly along with increasing knee angle. It stores energy when knee flexes and assists when knee extends. Both the mechanical experiment and comparison experiment have demonstrated that the PKAExo is able to provide nonlinear assistance torque for weight-climbing, thus decreasing the average maximum load of knee extensor by about 21 per cent, reducing muscle fatigue and enhancing wearer’s weight-climbing ability.

Originality/value

The authors construct theoretic maximum force model produced by knee extensor for weight-climbing in static situation and conduct a series of experiments to verify and revise the model, which is the fundamental reference for knee-assisting mechanism designed for weight-climbing. The authors have also provided and validated an assistant strategy and the mechanism based on the biomechanical analysis, which aims to translate wearer’s energy-providing mode form high load to mid-low load by storing energy when knee flexes and assisting when knee extends. The PKAExo decreases the maximum load of knee extensor, reduces muscle fatigue and helps people to easily climb with load.

Details

Industrial Robot: An International Journal, vol. 45 no. 4
Type: Research Article
ISSN: 0143-991X

Keywords

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Article
Publication date: 17 August 2015

Zhiqiang Ye, Zhi Zhang and Songlian Tang

The purpose of this paper is to test the relationship between stock dividends policy and liquidity of ex ante announcement to improve the traditional stock dividends liquidity…

1005

Abstract

Purpose

The purpose of this paper is to test the relationship between stock dividends policy and liquidity of ex ante announcement to improve the traditional stock dividends liquidity hypothesis.

Design/methodology/approach

The authors examine a sample of 2,088 which matching stocks between having stock dividends policy and having no dividends policy during 1999-2012 in Chinese listed firms. Using the multiple liner regression, the authors empirically tests the relationship between the possibility, payout ratio and timing choice of stock dividends and the liquidity of ex ante announcement.

Findings

The authors find that the possibility of stock dividends policy has negative relationship with liquidity, and the relationship of stock dividends and liquidity of ex ante announcement is influenced by the time choice of stock dividends.

Originality/value

This paper study the reason of stock dividends policy from the perspective of liquidity and improve the traditional stock dividends liquidity hypothesis.

Details

China Finance Review International, vol. 5 no. 3
Type: Research Article
ISSN: 2044-1398

Keywords

Available. Open Access. Open Access
Article
Publication date: 3 March 2022

Yuanyuan Hu and Jiali Fang

This study investigates whether corporate executives, who are university alumni, influence each other's firm corporate social responsibility (CSR) performance.

1506

Abstract

Purpose

This study investigates whether corporate executives, who are university alumni, influence each other's firm corporate social responsibility (CSR) performance.

Design/methodology/approach

Drawing on social network theory, the authors hypothesise that a firm's CSR performance is positively associated with its peer firms' average CSR performance when the executives of the firm and its peer firms are university alumni. The study employs data from 1,685 listed firms and 4,906 executives who graduated from 585 different universities in China and runs multivariate regressions.

Findings

The results reveal a sizeable university peer influence on CSR performance. Such influence is even stronger for executives who graduated from elite universities (e.g. 985 or 211 universities), and universities or programmes that provide more opportunities for alumni reunions or networking (e.g. MBAs/EMBAs). Executives who are more influential in making firm decisions (e.g. CEOs/CFOs), as well as firms that are more likely to mimic the behaviour of others, also show higher degrees of university peer influence.

Practical implications

The results highlight the role of education in ethical decision-making.

Originality/value

This study documents evidence on a new determinant of firm CSR performance. The study sheds light on the impact of non-institutionalised personal ties, for example, university alumni networks, on CSR performance.

Details

China Accounting and Finance Review, vol. 24 no. 1
Type: Research Article
ISSN: 1029-807X

Keywords

Available. Open Access. Open Access
Article
Publication date: 14 January 2020

Antonio Armillotta

This paper aims to investigate the feasibility of adding macro-textures to triangle meshes for additive manufacturing (AM) focusing on possible time and quality issues in both…

669

Abstract

Purpose

This paper aims to investigate the feasibility of adding macro-textures to triangle meshes for additive manufacturing (AM) focusing on possible time and quality issues in both software processing and part fabrication.

Design/methodology/approach

A demonstrative software tool was developed to apply user-selected textures to existing meshes. The computational procedure is a three-dimensional extension of the solid texturing method used in computer graphics. The tool was tested for speed and quality of results, considering also the pre- and post-processing operations required. Some textured meshes were printed by different processes to test build speed and quality.

Findings

The tool can handle models with realistic complexity in acceptable computation times. Parts are built without difficulties or extra-costs achieving a good aesthetic yield of the texture.

Research limitations/implications

The tool cannot reproduce sample patterns but requires the development of a generation algorithm for different type of textures. Mesh processing operations may take a long time when very fine textures are added to large parts.

Practical implications

Direct texturing can help obtain parts with aesthetic or functional textures without the need for surface post-treatments, which can be especially difficult and expensive for plastic parts.

Originality/value

The proposed method improves the uniformity and consistency of textures compared to existing approaches, and can support future systematic studies on the detail resolution of AM processes.

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