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Article
Publication date: 2 November 2015

Zheng Bo, Qi Zhao, Xiaorui Shuai, Jianhua Yan and Kefa Cen

– The purpose of this paper is to provide a quantitative assessment on the effect of wall roughness on the pressure drop of fluid flow in microchannels.

Abstract

Purpose

The purpose of this paper is to provide a quantitative assessment on the effect of wall roughness on the pressure drop of fluid flow in microchannels.

Design/methodology/approach

The wall roughness is generated by the method of random midpoint displacement (RMD) and the lattice Boltzmann BGK model is applied. The influences of Reynolds number, relative roughness and the Hurst exponent of roughness profile on the Poiseuille number are investigated.

Findings

Unlike the smooth channel flow, Reynolds number, relative roughness and the Hurst exponent of roughness profiles play critical roles on the Poiseuille number Po in rough microchannels. Modeling results indicate that, in rough microchannels, the rough surface configuration intensifies the flow-surface interactions and the wall conditions turn to dominate the flow characteristics. The perturbance of the local flows near the channel wall and the formation of recirculation regions are two main features of the flow-surface interactions.

Research limitations/implications

The fluid flow in parallel planes with surface roughness is considered in the current study. In other words, only two-dimensional fluid flow is investigated.

Practical implications

The LBM is a very useful tool to investigate the microscale flows.

Originality/value

A new method (RMD) is applied to generate the wall roughness in parallel plane and LBM is conducted to investigate the pressure drop characteristics in rough microchannels.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 25 no. 8
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 16 October 2009

Pengcheng Yan, Dongqing Liu and Bo Zheng

The purpose of this paper is to forecast the reliable storage life of a certain kind of equipment under the normal stress level.

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182

Abstract

Purpose

The purpose of this paper is to forecast the reliable storage life of a certain kind of equipment under the normal stress level.

Design/methodology/approach

Through the stepping stress acceleration life test and the failure mechanism analysis, this paper aims to confirm the stress level for the stepping stress acceleration life test of a certain kind of equipment and establish the data processing mathematical model and storage life forecasting method.

Findings

The stress level for the stepping stress acceleration life test of a certain kind of equipment is confirmed and the data processing mathematical model and storage life forecasting method is established.

Research limitations/implications

Availability of data is the main limitation affecting which model will be applied.

Practical implications

Useful advice for products' storage life forecasting.

Originality/value

The paper presents a new approach to product storage life estimation.

Details

Kybernetes, vol. 38 no. 10
Type: Research Article
ISSN: 0368-492X

Keywords

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Article
Publication date: 10 April 2009

Dongqing Liu, Bo Zheng and Pengcheng Yan

The purpose of this paper is to put forward a method which uses a computer to make a large number of simulated tests and determine the reference value of a system…

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151

Abstract

Purpose

The purpose of this paper is to put forward a method which uses a computer to make a large number of simulated tests and determine the reference value of a system reliability index according to a unit reliability index.

Design/methodology/approach

At the beginning of conducting an index demonstration and development on a new system, its unit reliability index can already reflect the unit reliability level accurately. Based on this characteristic, this index is used as the confidence lower limit of single side estimated in the unit reliability interval to find the failure distribution law of the unit. On this basis, a great number of simulated tests are made by a computer to calculate the unit failure number and reliability point estimated value every test.

Findings

The confidence lower limit of single side estimated in the system reliability interval is found by counting up the simulated test data of these units.

Research limitations/implications

Availability of data is the main limitation regarding which model will be applied.

Practical implications

A useful advice for system reliability analysis and calculation.

Originality/value

This paper presents a new approach of system reliability analysis.

Details

Kybernetes, vol. 38 no. 3/4
Type: Research Article
ISSN: 0368-492X

Keywords

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Article
Publication date: 1 February 2004

Bo Zheng, Fangping Cai and Jun Xu

Aiming at the product with long storage and one‐time application, this paper establishes the mathematical model of storage reliability and mathematical model system…

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974

Abstract

Aiming at the product with long storage and one‐time application, this paper establishes the mathematical model of storage reliability and mathematical model system storage reliability. According to the reliability test data of every part (subsystem) of the product, it evaluates the system reliability of the product and reliable storage life, and lower limit of system storage reliability and lower limit of reliable storage life on the credible level.

Details

Kybernetes, vol. 33 no. 2
Type: Research Article
ISSN: 0368-492X

Keywords

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Article
Publication date: 10 September 2021

Kunyong Chen, Yong Zhao, Jiaxiang Wang, Hongwen Xing and Zhengjian Dong

This paper aims to propose a fast and robust 3D point set registration method for pose estimation of assembly features with few distinctive local features in the…

Abstract

Purpose

This paper aims to propose a fast and robust 3D point set registration method for pose estimation of assembly features with few distinctive local features in the manufacturing process.

Design/methodology/approach

The distance between the two 3D objects is analytically approximated by the implicit representation of the target model. Specifically, the implicit B-spline surface is adopted as an interface to derive the distance metric. With the distance metric, the point set registration problem is formulated into an unconstrained nonlinear least-squares optimization problem. Simulated annealing nested Gauss-Newton method is designed to solve the non-convex problem. This integration of gradient-based optimization and heuristic searching strategy guarantees both global robustness and sufficient efficiency.

Findings

The proposed method improves the registration efficiency while maintaining high accuracy compared with several commonly used approaches. Convergence can be guaranteed even with critical initial poses or in partial overlapping conditions. The multiple flanges pose estimation experiment validates the effectiveness of the proposed method in real-world applications.

Originality/value

The proposed registration method is much more efficient because no feature estimation or point-wise correspondences update are performed. At each iteration of the Gauss–Newton optimization, the poses are updated in a singularity-free format without taking the derivatives of a bunch of scalar trigonometric functions. The advantage of the simulated annealing searching strategy is combined to improve global robustness. The implementation is relatively straightforward, which can be easily integrated to realize automatic pose estimation to guide the assembly process.

Details

Assembly Automation, vol. 41 no. 5
Type: Research Article
ISSN: 0144-5154

Keywords

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Article
Publication date: 5 September 2017

Peter Lok

The purpose of this paper is to explore how a neo-liberal nationalist discourse of China imagines the spatial identity of the post-1997 Hong Kong with reference to Lost in

Abstract

Purpose

The purpose of this paper is to explore how a neo-liberal nationalist discourse of China imagines the spatial identity of the post-1997 Hong Kong with reference to Lost in Hong Kong, a new Chinese middle-class film in 2015 with successful box office sales.

Design/methodology/approach

Textual analysis with the aid of psychoanalysis, postcolonial studies and semiotics is used to interpret the meaning of the film in this study. The study also utilizes the previous literature reviews about the formation of the Chinese national identity to help analyze the distinct identity of the Chinese middle class today.

Findings

The discussion pinpoints how the new Chinese middle class as neo-liberal nationalists take Hong Kong as a “bizarre national redemptive space”. While Hong Kong is cinematically constructed as such a national other, this paper argues that the Hong Kong in question stands not for itself but in a form of “reverse hallucination” for pacifying the new Chinese middle class’ trauma under the rapid neo-liberalization of China in the 1990s.

Originality/value

This paper shows the new of formation of the Chinese nationalist’s discourse, especially the new Chinese middle-class discourse on Hong Kong after 1997.

Details

Social Transformations in Chinese Societies, vol. 13 no. 2
Type: Research Article
ISSN: 1871-2673

Keywords

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Article
Publication date: 26 March 2021

Tong Che, Meng Ji, Xiabing Zheng and Bo Feng

The online-to-offline (O2O) business is developing rapidly and is highly popular in many countries. Nevertheless, O2O suffers from a large number of customer complaints…

Abstract

Purpose

The online-to-offline (O2O) business is developing rapidly and is highly popular in many countries. Nevertheless, O2O suffers from a large number of customer complaints that result in consumer loss. Focusing on the O2O context, this study integrates expectation disconfirmation theory (EDT) and justice theory to investigate consumers' dissatisfaction toward O2O websites.

Design/methodology/approach

A research model was proposed and tested using 329 survey responses.

Findings

Results show that the identified website disconfirmation and offline service disconfirmation could lead to consumer dissatisfaction. Importantly, the impacts of disconfirmation factors are contingent upon the justice perception of consumers. When a transaction is perceived as unfair, website disconfirmation arouses a higher level of dissatisfaction, and the negative emotions could transfer from O2O and damage the website's reputation.

Originality/value

This study explores the continuance intentions of customers toward O2O websites from a dissatisfaction perspective, with insights for future service studies and O2O service managers.

Details

Asia Pacific Journal of Marketing and Logistics, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1355-5855

Keywords

Content available
Article
Publication date: 3 December 2019

Wei Xue, Rencheng Zheng, Bo Yang, Zheng Wang, Tsutomu Kaizuka and Kimihiko Nakano

Automated driving systems (ADSs) are being developed to avoid human error and improve driving safety. However, limited focus has been given to the fallback behavior of…

Downloads
1037

Abstract

Purpose

Automated driving systems (ADSs) are being developed to avoid human error and improve driving safety. However, limited focus has been given to the fallback behavior of automated vehicles, which act as a fail-safe mechanism to deal with safety issues resulting from sensor failure. Therefore, this study aims to establish a fallback control approach aimed at driving an automated vehicle to a safe parking lane under perceptive sensor malfunction.

Design/methodology/approach

Owing to an undetected area resulting from a front sensor malfunction, the proposed ADS first creates virtual vehicles to replace existing vehicles in the undetected area. Afterward, the virtual vehicles are assumed to perform the most hazardous driving behavior toward the host vehicle; an adaptive model predictive control algorithm is then presented to optimize the control task during the fallback procedure, avoiding potential collisions with surrounding vehicles. This fallback approach was tested in typical cases related to car-following and lane changes.

Findings

It is confirmed that the host vehicle avoid collision with the surrounding vehicles during the fallback procedure, revealing that the proposed method is effective for the test scenarios.

Originality/value

This study presents a model for the path-planning problem regarding an automated vehicle under perceptive sensor failure, and it proposes an original path-planning approach based on virtual vehicle scheme to improve the safety of an automated vehicle during a fallback procedure. This proposal gives a different view on the fallback safety problem from the normal strategy, in which the mode is switched to manual if a driver is available or the vehicle is instantly stopped.

Details

Journal of Intelligent and Connected Vehicles, vol. 2 no. 2
Type: Research Article
ISSN: 2399-9802

Keywords

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Article
Publication date: 11 January 2016

Nirmala Gnanasundaram, Aruna Singh and M Ganesapillai

The purpose of this paper is to harness the potential of microwave pre-treatment to prepare carbon from locally available Sterculia foetida fruit shells for adsorption of…

Abstract

Purpose

The purpose of this paper is to harness the potential of microwave pre-treatment to prepare carbon from locally available Sterculia foetida fruit shells for adsorption of heavy metals, particularly Nickel ions (Ni++), from effluent.

Design/methodology/approach

The pre-treatment methods comprise conventional methods as sun drying and oven drying as well as high intensity microwave drying. Response surface methodology was employed to analyse the optimization of the process. The adsorption behavioural characteristics of the material were established applying adsorption isotherms.

Findings

Adsorption of Ni++ was found to be effective in microwave drying at output power of 300 W. It was observed that the maximum adsorption capacity was attained at pH 6; an adsorbent dosage of 0.25 mgml−1 and initial metal ion concentration of 20 ppm with an interactive effect of initial concentration and dosage.

Originality/value

The research puts emphasise on prospecting of novel biomass for carbonization and application of the same for effective adsorption. Available literature on Sterculia foetida is very limited and this work will serve to create database on the amenability of processing.

Details

Management of Environmental Quality: An International Journal, vol. 27 no. 1
Type: Research Article
ISSN: 1477-7835

Keywords

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Article
Publication date: 21 March 2016

Mingyu Nie, Zhi Liu, Xiaomei Li, Qiang Wu, Bo Tang, Xiaoyan Xiao, Yulin Sun, Jun Chang and Chengyun Zheng

This paper aims to effectively achieve endmembers and relative abundances simultaneously in hyperspectral image unmixing yield. Hyperspectral unmixing, which is an…

Abstract

Purpose

This paper aims to effectively achieve endmembers and relative abundances simultaneously in hyperspectral image unmixing yield. Hyperspectral unmixing, which is an important step before image classification and recognition, is a challenging issue because of the limited resolution of image sensors and the complex diversity of nature. Unmixing can be performed using different methods, such as blind source separation and semi-supervised spectral unmixing. However, these methods have disadvantages such as inaccurate results or the need for the spectral library to be known a priori.

Design/methodology/approach

This paper proposes a novel method for hyperspectral unmixing called fuzzy c-means unmixing, which achieves endmembers and relative abundance through repeated iteration analysis at the same time.

Findings

Experimental results demonstrate that the proposed method can effectively implement hyperspectral unmixing with high accuracy.

Originality/value

The proposed method present an effective framework for the challenging field of hyperspectral image unmixing.

Details

Sensor Review, vol. 36 no. 2
Type: Research Article
ISSN: 0260-2288

Keywords

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