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Article
Publication date: 31 March 2020

Zhenzhen Shang, Wendong Zhang, Guojun Zhang, Xiaoyong Zhang, Lansheng Zhang and Renxin Wang

The problem of port and starboard ambiguity will exist when only utilize the vector or scalar parameters. Meanwhile, the amplitude-phase error between the vector and…

Abstract

Purpose

The problem of port and starboard ambiguity will exist when only utilize the vector or scalar parameters. Meanwhile, the amplitude-phase error between the vector and scalar can also cause this problem. In this paper, a compound MEMS vector hydrophone which contains cilia vector microstructure and piezoelectric ceramic tube has been presented to solve the problem. Compared with traditional MEMS vector hydrophone, the compound MEMS vector hydrophone can realize the measurement of sound pressure and vibration velocity simultaneously.

Design/methodology/approach

A compound MEMS vector hydrophone has been presented. The unipolar directivity of the combined signal which combine the acoustic pressure and vibration velocity is used to achieve the direction of arrival (DOA). This paper introduced the working principle and the target detection mechanism of the compound vector hydrophone. The amplitude and phase error are analyzed and corrected in the standing wave tube. After that, the authors use beam-forming algorithm to estimate the DOA.

Findings

The experimental results in the standing wave tube and the external field verified the vector hydrophone's directional accuracy up to 1 and 5 degrees, respectively.

Practical implications

The research of compound vector hydrophone plays an important role in marine acoustic exploration and engineering applications.

Originality/value

This research provides a basis for MEMS hydrophone directivity theory. The compound vector hydrophone has been applied in the underwater location, with a huge market potential in underwater detection systems.

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Article
Publication date: 1 February 2011

Xiaoyong Zhang and Dinghuan Hu

The purpose of this paper is first, to develop constructs to measure three important concepts in the supply chain literature: contracts, trust and market environment, in…

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881

Abstract

Purpose

The purpose of this paper is first, to develop constructs to measure three important concepts in the supply chain literature: contracts, trust and market environment, in the Chinese context and to further investigate the relationships amongst these three concepts based on the formulated hypothesis.

Design/methodology/approach

The research methodology has strictly followed the recommended scale development procedures, which include specifying each constructs, item generation, data collection, reliability and validity test, and finally test hypothesis. The primary data were collected in October 2008 in Hubei Province, China. Both exploratory factor analysis and confirmatory factor analysis are applied to assess the reliability and validity of the three constructs.

Findings

In total, 22 items were retained to measure six dimensions for the three core concepts: contract (marketing and production), trust (reliability and benevolence), and market environments (diversity and volatility). Second, the finding supported this argument that contracts and trust functions as complements. Furthermore, a positive relationship between environmental uncertainty and the use of contractual governance was found.

Research limitations/implications

The measurement model for environmental volatility is less satisfied. More research should be carried out on the measurement of market environment in the future.

Originality/value

This paper identifies and validates key constructs underlying supply chain management research: contract, trust and market environment, in a Chinese context. These measurable concepts could be applied in similar settings to further investigate small‐scale farmer's position along the supply chain.

Details

China Agricultural Economic Review, vol. 3 no. 1
Type: Research Article
ISSN: 1756-137X

Keywords

Content available
Article
Publication date: 28 August 2009

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532

Abstract

Details

China Agricultural Economic Review, vol. 1 no. 4
Type: Research Article
ISSN: 1756-137X

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Article
Publication date: 30 January 2009

Xiaoyong Zhang and Lusine H. Aramyan

Chinese agri‐food chains consist of the millions of small scale farmers, who are not well structured and organized in the supply chain. Owing to market liberalization and…

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3277

Abstract

Purpose

Chinese agri‐food chains consist of the millions of small scale farmers, who are not well structured and organized in the supply chain. Owing to market liberalization and globalization, one of the most challenging issues along agri‐food chains in China is becoming the issue of how to link these small‐scale farmers into the modern chains. Consequently, it is essential for both policy makers and private sectors to understand the governance structure in agri‐food supply chains. Therefore, the purpose of this paper is to develop a theoretical framework for supply chain governance, including its antecedents and consequences, as well as a series of hypotheses for empirical testing.

Design/methodology/approach

A conceptual framework of chain governance is proposed in this study, where governance structure consists of two dimensions: contractual governance and relational governance. The study intends to propose a complementary relationship between contracts and relational aspects, such as trust, in the Chinese context. Future research is needed to empirically test this model.

Findings

The proposed conceptual model is unique, since the majority of the articles addressing this topic focuses on contract farming while limited research touches upon the issues of trust and relations. However, a combination of both contracting and relationships are seldom addressed.

Originality/value

This paper evaluates a novel concept of two dimensional governance structure in the agri‐food supply chain, where transaction cost economics theory and relational theory are combined to study the governance relationships between small scale producers in China and their buyers.

Details

China Agricultural Economic Review, vol. 1 no. 2
Type: Research Article
ISSN: 1756-137X

Keywords

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Article
Publication date: 17 August 2020

Juan Sebastian Gomez Bonilla, Maximilian Alexander Dechet, Jochen Schmidt, Wolfgang Peukert and Andreas Bück

The purpose of this paper is to investigate the effect of different heating approaches during thermal rounding of polymer powders on powder bulk properties such as…

Abstract

Purpose

The purpose of this paper is to investigate the effect of different heating approaches during thermal rounding of polymer powders on powder bulk properties such as particle size, shape and flowability, as well as on the yield of process.

Design/methodology/approach

This study focuses on the rounding of commercial high-density polyethylene polymer particles in two different downer reactor designs using heated walls (indirect heating) and preheated carrier gas (direct heating). Powder bulk properties of the product obtained from both designs are characterized and compared.

Findings

Particle rounding with direct heating leads to a considerable increase in process yield and a reduction in powder agglomeration compared to the design with indirect heating. This subsequently leads to higher powder flowability. In terms of shape, indirect heating yields not only particles with higher sphericity but also entails substantial agglomeration of the rounded particles.

Originality/value

Shape modification via thermal rounding is the decisive step for the success of a top-down process chain for selective laser sintering powders with excellent flowability, starting with polymer particles from comminution. This report provides new information on the influence of the heating mode (direct/indirect) on the performance of the rounding process and particle properties.

Details

Rapid Prototyping Journal, vol. 26 no. 9
Type: Research Article
ISSN: 1355-2546

Keywords

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Article
Publication date: 2 August 2019

Le Wang, Zao Sun, Xiaoyong Dai, Yixin Zhang and Hai-hua Hu

The purpose of this paper is to facilitate understanding of how to mitigate the privacy concerns of users who have experienced privacy invasions.

Abstract

Purpose

The purpose of this paper is to facilitate understanding of how to mitigate the privacy concerns of users who have experienced privacy invasions.

Design/methodology/approach

Drawing on the communication privacy management theory, the authors developed a model suggesting that privacy concerns form through a cognitive process involving threat-coping appraisals, institutional privacy assurances and privacy experiences. The model was tested using data from an empirical survey with 913 randomly selected social media users.

Findings

Privacy concerns are jointly determined by perceived privacy risks and privacy self-efficacy. The perceived effectiveness of institutional privacy assurances in terms of established privacy policies and privacy protection technology influences the perceptions of privacy risks and privacy self-efficacy. More specifically, privacy invasion experiences are negatively associated with the perceived effectiveness of institutional privacy assurances.

Research limitations/implications

Privacy concerns are conceptualized as general concerns that reflect an individual’s worry about the possible loss of private information. The specific types of private information were not differentiated.

Originality/value

This paper is among the first to clarify the specific mechanisms through which privacy invasion experiences influence privacy concerns. Privacy concerns have long been viewed as resulting from individual actions. The study contributes to literature by linking privacy concerns with institutional privacy practice.

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Article
Publication date: 19 September 2019

Jun Sun, Xiao Zhang, Jianxiong Zhu, Yaming Gao, Hu Wang, Xiaoyong Zhao, Qin Teng, Yanping Ren and Guixiang Zhu

Currently, lubrication analysis of piston ring is generally done under engine rated operating condition. However, the engine (such as the vehicle engine) does not always…

Abstract

Purpose

Currently, lubrication analysis of piston ring is generally done under engine rated operating condition. However, the engine (such as the vehicle engine) does not always operate in rated operating condition, and its operating condition changes frequently in actual use. In addition, the lubrication status of piston ring is generally assumed as the flooded lubrication or a certain form of poor lubrication in most of the lubrication analysis.

Design/methodology/approach

In this paper, based on the equations about the flow rate of lubricating oil and the variation of control volume, the flow model of lubricating oil in the piston ring-cylinder liner conjunction is established. The lubrication analysis of piston ring for a four-stroke engine under different engine operating conditions is done, in which the lubricating oil at the inlet of piston ring is considered as the lubricating oil attached on the relevant location of cylinder wall after the piston ring moves over at the previous stroke.

Findings

There is remarkable difference for the lubrication characteristics of the piston ring under different engine operating conditions. The worst lubrication status of piston ring may not take place under engine rated operating condition.

Originality/value

In this paper, based on the measured engine cylinder pressure, the lubrication analysis of piston ring for a four-stroke engine under different engine operating conditions is done in which the lubricating oil supply condition at the inlet of piston ring is considered. The results of this paper are helpful for the design and research of engine piston ring-cylinder liner conjunction.

Details

Industrial Lubrication and Tribology, vol. 72 no. 1
Type: Research Article
ISSN: 0036-8792

Keywords

Content available
Article
Publication date: 9 April 2019

Yibekal Abebe Tessema, Jonas Joerin and Anthony Patt

The geographical range of agricultural crops is shifting because of climate change. Reducing the potential negative impact of this shift requires efficient crop switching…

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1530

Abstract

Purpose

The geographical range of agricultural crops is shifting because of climate change. Reducing the potential negative impact of this shift requires efficient crop switching at farm level. Yet there are scant studies that examine how crop switching is currently taking place and what factors facilitate the process. Even these few existing studies often based their analysis on inadequately established causal link between climate change and switching decisions. This study aims to identify the specific switching decisions that are primarily motivated by climate change, and their determinants.

Design/methodology/approach

The study used a household survey on 190 households in Semien Shewa Zone in Ethiopia. Subjective rating of farmers was used to identify the relative importance of climate change in motivating the different types of switching decisions. A logit model is used to identify determinants of crop switching decisions primarily motivated by climate change.

Findings

Farmers in the study area are currently abandoning certain crops as a response to climate change. The adoption of new crops is, however, mainly attributed to price changes. Most farmers who abandoned at least one crop adopted mung bean mainly due to its price advantages. As expected, crop switching as an adaptation strategy is more prevalent particularly in drier and hotter agroecologies. The logit model showed that crop switching is strongly correlated with land size and agroecology.

Originality/value

This paper provides an in-depth examination of crop switching as an adaptation strategy to climate change. Crop switching is an adaptation strategy that is expected to substantially reduce the damage from climate change in agriculture. The findings are particularly relevant for adaptation planning in the context of smallholder agriculture.

Details

International Journal of Climate Change Strategies and Management, vol. 11 no. 3
Type: Research Article
ISSN: 1756-8692

Keywords

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Article
Publication date: 8 April 2014

Jun Sun, Xinlong Zhu, Liang Zhang, Xianyi Wang, Chunmei Wang, Hu Wang and Xiaoyong Zhao

Current lubrication analyses of misaligned journal bearings were generally performed under some given preconditions. To make the lubrication analysis closer to the actual…

Abstract

Purpose

Current lubrication analyses of misaligned journal bearings were generally performed under some given preconditions. To make the lubrication analysis closer to the actual situation and usable to the journal bearing design, the purpose of this paper was to calculate the lubrication characteristics of misaligned journal bearings considering the viscosity-pressure effect of the oil, the surface roughness and the elastic deformation of the journal bearing at the same time.

Design/methodology/approach

The lubrication of bearings was analyzed using the average Reynolds equation. The deformation of the bearing surface under oil film pressure was calculated by a compliance matrix method. The compliance matrix was established by finite element analysis of the bearing housing. The viscosity-pressure and viscosity–temperature equations were used in the analysis.

Findings

The oil viscosity-pressure relationship has a significant effect on the lubrication of misaligned journal bearings. The surface roughness will affect the lubrication of misaligned journal bearings when the eccentricity ratio and angle of journal misalignment are all large. The directional parameter of the surface has an obvious effect on the lubrication of misaligned journal bearings. The deformation of the bearing surface has a remarkable effect on the lubrication of misaligned journal bearings.

Originality/value

The lubrication characteristics of misaligned journal bearings were calculated considering the viscosity-pressure effect of the oil, the surface roughness and the elastic deformation of the journal bearing at the same time. The results of this paper are helpful to the design of the bearing.

Details

Industrial Lubrication and Tribology, vol. 66 no. 3
Type: Research Article
ISSN: 0036-8792

Keywords

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Book part
Publication date: 6 June 2016

Jingjing Yang, Chris Ryan and Lingyun Zhang

Abstract

Details

Social Conflict and Harmony: Tourism in China’s Multi-Ethnic Communities
Type: Book
ISBN: 978-1-78441-356-9

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