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1 – 10 of over 2000
Article
Publication date: 17 May 2021

Xian Zhang, Gedong Jiang, Hao Zhang, Xialun Yun and Xuesong Mei

The purpose of this paper is to analyze the dependent competing failure reliability of harmonic drive (HD) with strength failure and degradation failure.

Abstract

Purpose

The purpose of this paper is to analyze the dependent competing failure reliability of harmonic drive (HD) with strength failure and degradation failure.

Design/methodology/approach

Based on life tests and stiffness degradation experiments, Wiener process is used to establish the accelerated performance degradation model of HD. Model parameter distribution is estimated by Bayesian inference and Markov Chain Monte Carlo (MCMC) and stiffness degradation failure samples are obtained by a three-step sampling method. Combined with strength failure samples of HD, copula function is used to describe the dependence between strength failure and stiffness degradation failure.

Findings

Strength failure occurred earlier than degradation failure under high level accelerated condition; degradation failure occurred earlier than strength failure under medium- or low-level accelerated condition. Gumbel copula is the optimum copula function for dependence modeling of strength failure and stiffness degradation failure. Dependent competing failure reliability of HD is larger than independent competing failure reliability.

Originality/value

The reliability evaluation method of dependent competing failure of HD with strength failure and degradation failure is first proposed. Performance degradation experiments during accelerated life test (ALT), step-down ALT and life test under rated condition are conducted for Wiener process based step-down accelerated performance degradation modeling.

Details

Engineering Computations, vol. 38 no. 10
Type: Research Article
ISSN: 0264-4401

Keywords

Open Access
Article
Publication date: 16 October 2017

Hao Zhang, Bin Qiu and Keming Zhang

The purpose of this paper is to develop a quantitative risk assessment method for agricultural products cold chain logistics to assess the condition of the fresh…

6264

Abstract

Purpose

The purpose of this paper is to develop a quantitative risk assessment method for agricultural products cold chain logistics to assess the condition of the fresh agricultural products cold chain process objectively and accurately.

Design/methodology/approach

A risk assessment index system of agricultural products cold chain logistics is designed on the basis of the risk identification for the process of agricultural products cold chain logistics. This paper first uses catastrophe progression method and a new maximum deviation method to build an improved catastrophe progression assessment model for agricultural products cold chain logistics. In order to verify the reliability and validity of the model, two representative enterprises are selected as the case in the study.

Findings

The results in the empirical research indicate strong support for the assessment model and coincide with the reality. The risk assessment index system can also reflect the key risk factors from agricultural products cold chain logistics scientifically. In addition, the improved catastrophe progression assessment method proposed in this paper can be scientific and reasonable to predict risk.

Research limitations/implications

This paper contributes to provide a new risk assessment model for agricultural products cold chain logistics. The new model overcomes the limitation of subjective empowerment and it increases the objectivity and scientificity in the process of cold chain logistics risk assessment. This paper also shows that practitioners involved in the field of products cold chain logistics can manage the potential risk by a set of scientific methods for assessing the risk before the accident.

Practical implications

The paper provides a practical guideline to practitioners, especially for cold chain logistics managers, relevant management departments, and cold chain logistics management consultants. It is proved that the new risk assessment method and the risk assessment index system of agricultural products cold chain logistics can help them assess the risk scientifically and reasonably.

Originality/value

Although the calculation is simple, the new model can overcome the limitation of subjective empowerment scientifically and reasonably, and thus has important practical value.

Details

Industrial Management & Data Systems, vol. 117 no. 9
Type: Research Article
ISSN: 0263-5577

Keywords

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…

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. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0143-991X

Keywords

Open Access
Article
Publication date: 5 August 2021

Ye Duan, Zenglin Han, Hao Zhang and Hongye Wang

Environmental problems such as CO2 (Carbon Dioxide) emissions have seriously affected the development of the steel industry, which has urged the industry to adopt a more…

Abstract

Purpose

Environmental problems such as CO2 (Carbon Dioxide) emissions have seriously affected the development of the steel industry, which has urged the industry to adopt a more effective emission reduction policy. This paper aims to analyze the impact of various CO2 emission reduction policies combinations on the economic benefits and environmental changes of the steel industry and to determine the scope of application.

Design/methodology/approach

To compare the impact and applicable implementation conditions, a production decision game model that incorporates these two policies has been constructed. Short-, medium- and long-term constraints are set on the emission reduction indicators and the indicators’ changes under various scenarios are compared.

Findings

In the case of a single emission reduction policy, the carbon trading (CT) mechanism is better than the carbon tax mechanism. The mixed carbon trading mechanism is superior to the mixed carbon tax mechanism in terms of total output and subsidies, but worse in terms of overall social welfare, producer surplus and macro losses.

Originality/value

This paper constructs multiple emission reduction and production backgrounds and discusses the impact of the comprehensive implementation of these policies, which is practically absent in previous studies. It is in line with the current industrial policy for stable production and environmental protection and also provides a reference for the formulation of detailed policies in the future.

Details

International Journal of Climate Change Strategies and Management, vol. 13 no. 3
Type: Research Article
ISSN: 1756-8692

Keywords

Article
Publication date: 16 February 2022

Bao Chao, Chaoyong Zhang, Yu Zhang, Hongfei Guo, Yaping Ren and Hao Zhang

This paper aims to provide feasible countermeasures for the application of lean manufacturing in automatic sand casting workshops to optimize production line balance.

Abstract

Purpose

This paper aims to provide feasible countermeasures for the application of lean manufacturing in automatic sand casting workshops to optimize production line balance.

Design/methodology/approach

A production line balance optimization model for sand casting workshops is proposed. The value stream mapping (VSM) approach is applied to diagnose the problems in the production process. An optimization scheme is established based on eliminate, combine, rearrange, simplify and increase theory and Kanban management method. Further, simulation is done to compare current VSM and future VSM.

Findings

After implementing the proposed model, findings indicated that the idle time of equipment was effectively reduced, the line of balance of the production line was increased by 44.7%, the production lead time was shortened by 60.3% and the production capacity was increased by 50.0%.

Research limitations/implications

Application of the optimization model in this study is limited to sand casting workshops that have realized automatic or semi-automatic production.

Originality/value

This paper provides an optimization model for the implementation of lean manufacturing in sand casting workshops and provides a reference case that reflects the actual application of lean manufacturing tools in a real situation.

Details

International Journal of Lean Six Sigma, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2040-4166

Keywords

Article
Publication date: 16 September 2021

Hao Zhang and Zengguang Ma

Value co-creation is known to increase innovation, but it can backfire under certain conditions. The purpose of this study is to investigate co-creation activities for…

Abstract

Purpose

Value co-creation is known to increase innovation, but it can backfire under certain conditions. The purpose of this study is to investigate co-creation activities for their effects on consumer perceptions of symbolic designs and to investigate the mediation effect of psychological distance and the moderation effect of peer feedback.

Design/methodology/approach

Three studies were designed by using a survey (Study 1) and two controlled laboratory experiments (Study 2 and 3). Study 1 had a sample size of 160 respondents and examined whether innovative ideas and behavior intensity had different impact on symbolic design. Study 2 had a sample size of 204 respondents and verified the interaction effect between innovativeness and intensity and to show that psychological distance is the underlying internal mechanism. Study 3 examined peer feedback as a critical moderator by using a sample of 235 participants.

Findings

Results show that idea innovativeness positively influences perceptions of symbolic design, while behavior intensity has a negative influence. The studies verify that innovativeness interacts with intensity to affect perceptions of symbolic design. Psychological distance explains why it is difficult to co-create luxury goods. Peer feedback is revealed to be a new moderator.

Originality/value

This research uniquely develops an extensive theory-based conceptual model and highlights two dimensions of value co-creation that interact with product design. The article emphasizes the theoretical and practical importance of studying both direct and indirect moderating effects.

Details

Journal of Research in Interactive Marketing, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2040-7122

Keywords

Article
Publication date: 11 April 2018

Hao Zhang and Brenda Chawner

Homelessness has been a growing problem in many countries since the 1980s. The purpose of this paper is to examine homeless peoples’ perspectives on public library…

1882

Abstract

Purpose

Homelessness has been a growing problem in many countries since the 1980s. The purpose of this paper is to examine homeless peoples’ perspectives on public library services, and to compare these with the attitudes of library staff.

Design/methodology/approach

Eight interviews have been conducted with rough sleepers and formerly homeless library patrons to examine their experiences, needs and expectations or the library. In addition, four library staff have been interviewed about their attitudes to services for members of the homeless community.

Findings

Most rough sleepers and formerly homeless patrons who participated in this research viewed the public library as a safe place because it offered a welcoming atmosphere, access to a variety of resources and services targeted at the homeless. Nonetheless, sleeping has always been a major reason for their use of the library. Most staff members agreed that providing services targeted toward rough sleepers changed the dynamic between staff and the homeless patrons, but there was some disagreement between staff members about whether targeted services were the most appropriate approach.

Practical implications

Understanding homeless and rough sleepers’ expectations for public library services may be useful in revising policy and developing services for this community. In particular, developing partnerships with organisations supporting the homeless is an effective way of developing relevant services for this often-marginalised group.

Originality/value

Little research has considered public library services from the perspective of homeless people. This research is intended to fill that gap.

Details

Global Knowledge, Memory and Communication, vol. 67 no. 4/5
Type: Research Article
ISSN: 0024-2535

Keywords

Article
Publication date: 18 February 2019

Yang Liu, Hao Zhang, Lingen Wang, Xuejun Fan, Guoqi Zhang and F. Sun

Crack and stress distribution on dies are key issues for the pressure-assisted sintering bonding of power modules. The purpose of this research is to build a relationship…

Abstract

Purpose

Crack and stress distribution on dies are key issues for the pressure-assisted sintering bonding of power modules. The purpose of this research is to build a relationship among stress distributions, sintering sequences and sintering pressures during the sintering processes.

Design/methodology/approach

Three sintering sequences, S(a), S(b) and S(c), have been designed for the double-side assembly of power module in this paper. Experiments and finite element method (FEM) analysis are conducted to investigate the crack and stress distribution.

Findings

The sintering sequence had significant effects on the crack generation in the chips during the sintering process under 30-MPa pressure. The simulation results revealed that the module sintered by S(a) showed lower chip stress than those by the other two sintering sequences under 30 MPa. In contrast, the chip stress is the highest when the sintering sequence follows S(b). The simulation results explained the crack generation and prolongation in the experiments. S(a) was recommended as the best sintering sequence because of the lowest chip stress and highest yield rate.

Originality/value

This study investigated the stress distributions of the double-side sintered power modules under different sintering pressures. Based on the results of experiments and FEM analysis, the best sintering sequence design is provided under various sintering pressures.

Details

Soldering & Surface Mount Technology, vol. 31 no. 1
Type: Research Article
ISSN: 0954-0911

Keywords

Article
Publication date: 3 March 2020

Xian Zhang, Gedong Jiang, Hao Zhang, Xialun Yun and Xuesong Mei

The purpose of this paper is to analyze the time-dependent reliability of harmonic drive.

Abstract

Purpose

The purpose of this paper is to analyze the time-dependent reliability of harmonic drive.

Design/methodology/approach

The transient finite element analysis (FEA) of harmonic drive is established to calculate the stress under different loads. Combined with the residual strength model and random variables, the time-dependent reliability model of harmonic drive is deduced by the stochastic perturbation method and Edgeworth series. Based on accelerated life tests, the degradation parameters are estimated by maximizing likelihood function. Under variable load, the key stress from transient FEA is transformed into probability density function by kernel density estimation, and the residual strength model is modified by adding adjustment factors to deal with strength degradation under different loads.

Findings

The critical position of stress concentration from transient FEA is consistent with the fatigue fracture position at the accelerated life test sample. Compared with the time-dependent reliability method with equivalent circular-shell static stress or empirical degradation parameters, the proposed method has the smallest prediction error of failure life. Under variable load, the state function should be expanded to second-order series for avoiding error items relevant to variance. The failure life expectation under random variable load is smaller than that under constant load.

Originality/value

The time-dependent reliability method of harmonic drive is firstly proposed under constant and variable load. The transient FEA of harmonic drive is established to calculate the stress for strength analysis. The accelerated life test of harmonic drive is conducted for degradation parameters estimation. The adjustment factor is added to the residual strength model for strength degradation under different loads.

Details

Engineering Computations, vol. 37 no. 7
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 6 April 2022

Peng Wang, Chunxiao Song, Renquan Dong, Peng Zhang, Shuang Yu and Hao Zhang

Aiming at the problem that quadruped crawling robot is easy to collide and overturn when facing obstacles and bulges in the process of complex slope movement, this paper…

Abstract

Purpose

Aiming at the problem that quadruped crawling robot is easy to collide and overturn when facing obstacles and bulges in the process of complex slope movement, this paper aims to propose an obstacle avoidance gait planning of quadruped crawling robot based on slope terrain recognition.

Design/methodology/approach

First, considering the problem of low uniformity of feature points in terrain recognition images under complex slopes, which leads to too long feature point extraction time, an improved ORB (Oriented FAST and Rotated BRIEF) feature point extraction method is proposed; second, when the robot avoids obstacles or climbs over bumps, aiming at the problem that the robustness of a single step cannot satisfy the above two motions at the same time, the crawling gait is planned according to the complex slope terrain, and a robot obstacle avoidance gait planning based on the artificial potential field method is proposed. Finally, the slope walking experiment is carried out in the Robot Operating System.

Findings

The proposed method provides a solution for the efficient walking of robot under slope. The experimental results show that the extraction time of the improved ORB extraction algorithm is 12.61% less than the original ORB extraction algorithm. The vibration amplitude of the robot’s centroid motion curve is significantly reduced, and the contact force is reduced by 7.76%. The time it takes for the foot contact force to stabilize has been shortened by 0.25 s. This fact is verified by simulation and test.

Originality/value

The method proposed in this paper uses the improved feature point recognition algorithm and obstacle avoidance gait planning to realize the efficient walking of quadruped crawling robot on the slope. The walking stability of quadruped crawling robot is tested by prototype.

Details

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

Keywords

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