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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…

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

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Article
Publication date: 2 July 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…

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

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Article
Publication date: 5 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

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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

Content available
Article
Publication date: 18 November 2020

Yuyang Zhang, Yonggang Leng, Hao Zhang, Xukun Su, Shuailing Sun, Xiaoyu Chen and Junjie Xu

An appropriate equivalent model is the key to the effective analysis of the system and structure in which permanent magnet takes part. At present, there are several…

Abstract

Purpose

An appropriate equivalent model is the key to the effective analysis of the system and structure in which permanent magnet takes part. At present, there are several equivalent models for calculating the interacting magnetic force between permanent magnets including magnetizing current, magnetic charge and magnetic dipole–dipole model. How to choose the most appropriate and efficient model still needs further discussion.

Design/methodology/approach

This paper chooses cuboid, cylindrical and spherical permanent magnets as calculating objects to investigate the detailed calculation procedures based on three equivalent models, magnetizing current, magnetic charge and magnetic dipole–dipole model. By comparing the accuracies of those models with experiment measurement, the applicability of three equivalent models for describing permanent magnets with different shapes is analyzed.

Findings

Similar calculation accuracies of the equivalent magnetizing current model and magnetic charge model are verified by comparison between simulation and experiment results. However, the magnetic dipole–dipole model can only accurately calculate for spherical magnet instead of other nonellipsoid magnets, because dipole model cannot describe the specific characteristics of magnet's shape, only sphere can be treated as the topological form of a dipole, namely a filled dot.

Originality/value

This work provides reference basis for choosing a proper model to calculate magnetic force in the design of electromechanical structures with permanent magnets. The applicability of different equivalent models describing permanent magnets with different shapes is discussed and the equivalence between the models is also analyzed.

Details

Journal of Intelligent Manufacturing and Special Equipment, vol. 1 no. 1
Type: Research Article
ISSN: 2633-6596

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Article
Publication date: 8 July 2019

Shuang Wang, Gedong Jiang, Xuesong Mei, Chuang Zou, Xian Zhang and Hao Zhang

Because of the compact structure, short flexspline (FS) harmonic drive (HD) is increasingly used. The stress calculation of FS is very important in design and optimization…

Abstract

Purpose

Because of the compact structure, short flexspline (FS) harmonic drive (HD) is increasingly used. The stress calculation of FS is very important in design and optimization of HD system. This paper aims to study the stress calculation methods for short FS, based on mechanics analysis and finite element method (FEM).

Design/methodology/approach

A rapid stress calculation method, based on mechanics analysis, is proposed for the short FS of HD. To verify the stress calculation precision of short FS, a complete finite element model of HD is established. The results of stress and deformation of short FS in different lengths are solved by FEM.

Findings

Through the rapid calculation method, the analytical relationship between circumferential stress and length of cylinder was obtained. And the circumferential stress has proportional relation with the reciprocal of squared length. The FEM results verified that the rapid stress calculation method could obtain accurate results.

Research limitations/implications

The rapid mechanics analysis method is practiced to evaluate the strength of FS at the design stage of HD. And the complete model of HD could contribute to improving the accuracy of FEM results.

Originality/value

The rapid calculation method is developed based on mechanics analysis method of cylinder and equivalent additional bending moment model, through which the analytical relationship between circumferential stress and length of cylinder was obtained. The complete three-dimensional finite element model of HD takes the stiffness of bearing into consideration, which can be used in the numerical simulation in the future work to improve the accuracy.

Details

Engineering Computations, vol. 36 no. 6
Type: Research Article
ISSN: 0264-4401

Keywords

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Article
Publication date: 2 August 2019

Jing Peng, Guoping Tu, Yanhong Liu, Hao Zhang and Bibing Leng

The purpose of this paper is to provide a feasible scheme for local governments to regulate corporate environmental data fraud and to discuss whether the influence of the…

Abstract

Purpose

The purpose of this paper is to provide a feasible scheme for local governments to regulate corporate environmental data fraud and to discuss whether the influence of the construction of online information disclosure platform on the environmental behavior of enterprises is better than the offline spot check.

Design/methodology/approach

Under the background of changing environmental fees into taxes in China, this paper conducts evolutionary game analysis between local governments and enterprises in view of the existing problem of environmental data fraud. Furthermore, through the introduction of government information disclosure platform, this paper discusses the impact of the integration of direct government regulation and indirect public concern regulation on the evolution of environmental behavior of both sides. Finally, the evolutionary game is simulated by adopting system dynamics to analyses the implementation effect of different cases on the game process and game equilibrium.

Findings

The results showed that the introduction of information disclosure platform mechanism can effectively suppress the fluctuations existing in the game play and stabilize the game. Moreover, it is worth noting that the regulatory effect of local governments investing part of the monitoring cost in the construction of online information platform is proved to be better than that of putting all the monitoring cost into offline investigation. While optimizing the monitoring cost allocation, the local government still needs to attach great importance to organically combine the attention of the public and media with the governmental official platform.

Practical implications

The obtained results confirm that the proposed model can assist local government in refining the effects of their environmental regulatory decisions, especially in the case of corporate data fraud under environmental tax enforcement.

Originality/value

Previous literature only suggested that local governments should reduce the cost of supervision to change the corporate behavior to a better direction, but no further in-depth study. Thus, this study fills the gap by discussing the positive transformation effect of local government cost allocation scheme on corporate environmental behavior.

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Article
Publication date: 10 June 2019

Jie He, Hao Zhang and Alastair M. Morrison

This paper aims to explore the impacts of corporate social responsibility (CSR) on employee organizational citizenship behavior (OCB) and task performance in hospitality…

Abstract

Purpose

This paper aims to explore the impacts of corporate social responsibility (CSR) on employee organizational citizenship behavior (OCB) and task performance in hospitality. The existing research emphasizes the effects of CSR on organizational performance at a macro level. There is a need to explore social responsibility at a micro level, more precisely, the effects on employee OCB and task performance. Significant evidence shows that CSR positively affects employee OCB. However, there is scant research explaining how CSR impacts OCB and consequently task performance. The main purpose of this investigation was to bridge this gap by analyzing how CSR influences employee OCB and task performance in hospitality based on social identity theory.

Design/methodology/approach

A theoretical model was proposed and tested through sequential mediation regressions based on a survey of 296 employees in the hospitality sector in China.

Findings

The results showed that CSR has a positive effect on social identity, which in turn influences employee OCB and consequently task performance. Social identity and OCB play sequential mediation roles between CSR and task performance. Additionally, there is an inverted U-shape relationship between OCB and task performance.

Research limitations/implications

This research illustrates how and why CSR impacts employee OCB and task performance based on social identity theory. More specifically, a sequential mediation chain exists between CSR and task performance. The study suggests that hospitality businesses adopting CSR promote employee identification with their companies that leads to enhanced OCB and task performance. This may be an effective way to motivate employees through hospitality businesses accepting greater social responsibility. Additionally, it was found that OCB has a positive effect on task performance, and there is an inverted U-shape relationship between OCB and task performance.

Originality/value

CSR can be applied as the employee management practice in the hospitality sector. CSR has a positive impact on organizational identification that contributes to individual outcomes such as OCB and task performance at work.

Details

International Journal of Contemporary Hospitality Management, vol. 31 no. 6
Type: Research Article
ISSN: 0959-6119

Keywords

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Article
Publication date: 12 June 2017

Feng Luo, Guodong Li and Hao Zhang

The purpose of this paper is to obtain the mechanical behavior and damage mechanism of the coal and rock near the stope under the stress state and stress paths of the…

Abstract

Purpose

The purpose of this paper is to obtain the mechanical behavior and damage mechanism of the coal and rock near the stope under the stress state and stress paths of the surrounding rock with the dynamic mining.

Design/methodology/approach

Through the three-axial compression test and the uniaxial compression test by meso experiment device, the mechanical behavior and fracture evolution process of coal and rock were studied, and the acoustic emission (AE) characteristics under uniaxial compression of the coal and rock were contrasted.

Findings

Under the three-axial compression, the strength of coal and rock enhance significantly by confining pressure. The volume of outburst coal shows obvious stages: compression is followed by expansion. The coal first appear to undergo compaction under vertical stress due to volume decrease, but with the development of micro- and macro-cracks, the specimens appeared to expand; under the uniaxial compression, through the comparison of stress–strain relationship and the crack propagation process, stress drop and fracture of coal have obvious correlation. The destruction of coal was gradual due to the slow and steady accumulation of internal damage. Due to the influence of the end effect, the specimens show the “conjugate double shear failure”. The failure process of the coal and rock and the characteristics of the AEs have a corresponding relationship: the failure causes a large number of AE events. Before the events peak, there was an initial stage, calm growth stage and explosive growth stage. There were some differences between the rock and coal in the characteristics of the AE.

Originality/value

These research studies are conducted to provide guidance on the basis of mine disaster prevention and control.

Details

World Journal of Engineering, vol. 14 no. 3
Type: Research Article
ISSN: 1708-5284

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Article
Publication date: 3 January 2017

Hao Zhang, Yang Liu, Fenglian Sun, Gaofang Ban and Jiajie Fan

This paper aimed to investigate the effects of nano-copper particles on the melting behaviors, wettability and defect formation mechanism of the Sn58Bi composite solder pastes.

Abstract

Purpose

This paper aimed to investigate the effects of nano-copper particles on the melting behaviors, wettability and defect formation mechanism of the Sn58Bi composite solder pastes.

Design/methodology/approach

In this paper, the mechanical stirring method was used to get the nano-composite solder pastes.

Findings

Experimental results indicated that the addition of 3 wt.% (weight percentage) 50 nm copper particles showed limited effects on the melting behaviors of the Sn58Bi composite solder paste. The spreading rate of the Sn58Bi composite solder paste showed a decreasing trend with the increase of the weight percentage of 50 nm copper particles from 0 to 3 wt.%. With the addition of copper particles of diameters 50 nm, 500 nm or 6.5 μm into the Sn58Bi solder paste, the porosities of the three types of solder pastes showed a similar trend. The porosity increased with the increase of the weight percentage of copper particles. Based on the experimental results, a model of the void formation mechanism was proposed. During reflow, the copper particles reacted with Sn in the matrix and formed intermetallic compounds, which gathered around the voids produced by the volatilization of flux. The exclusion of the voids was suppressed and eventually led to the formation of defects.

Originality/value

This study provides an optimized material for the second and third level packaging. A model of the void formation mechanism was proposed.

Details

Microelectronics International, vol. 34 no. 1
Type: Research Article
ISSN: 1356-5362

Keywords

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