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Article
Publication date: 16 July 2019

Fuying Zhang, Hao Che Shui and Yufei Zhang

The purpose of this paper is based on the response surface method, the authors determined the conditions for achieving the optimum rubber-sealing performance by using the…

Abstract

Purpose

The purpose of this paper is based on the response surface method, the authors determined the conditions for achieving the optimum rubber-sealing performance by using the maximum contact stress as the response value.

Design/methodology/approach

A two-dimensional model of a compression packer rubber was established by finite-element analysis software. Under the single axial load of 53.85 MPa, the four single factors of the end-face inclination angle, subthickness, height of rubber and friction coefficient of the rubber were analyzed.

Findings

Results show that the optimum sealing performance of the rubber tube is achieved when the end-face angle is equal to 45º and the thickness of the rubber tube is 9 mm. The response surface designed by Box–Behnken shows that the sealing performance of the rubber tube is the optimum when the end-face inclination angle is 48.1818°, the subthickness is 9 mm, the height of rubber is 90 mm and the friction coefficient is 0.1. Verification test results show that the model is reliable and effective.

Originality/value

Packer operations are performed downhole, and research on real experiments is limited. In this work, the feasibility of such experiments is determined by comparing finite-element modeling with actual experiments, and the results have guiding significance for actual downhole operations.

Details

Industrial Lubrication and Tribology, vol. 71 no. 5
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 1 June 2012

Yufei Zhang, Youliang Li and Qiaoling Hu

The purpose of this paper is to fabricate colorless cotton fabrics with good antibacterial activity and durability.

Abstract

Purpose

The purpose of this paper is to fabricate colorless cotton fabrics with good antibacterial activity and durability.

Design/methodology/approach

Chitosan (CS) based silver nanoparticles (AgNPs) were formed in CS solutions as the antibacterial agent. The reducing agent was sodium borohyride. The concentrations of the CS solutions ranged from 0.1 to 1 percent (w/v). Cotton fabrics were impregnated by these CS/AgNPs solutions.

Findings

All of these fabrics exhibited superior antibacterial activities. The antibacterial activity still showed great efficiency even after 81 home launderings. Moreover, the results of color change and whiteness indicated that the cotton fabrics treated by CS/AgNPs complex with higher CS concentration had less color change compared with other samples.

Practical implications

Fabrics treated by this method could reduce the brown color brought by AgNPs. The paper also suggests that cotton fabrics treated by AgNPs formed in a relatively higher CS concentration not only had good antibacterial activity but also were colorless.

Originality/value

The influence of CS ratio in CS/AgNPs complexes on the antibacterial activity and color of cotton fabrics was studied, which has been rarely reported in previous papers. The fabrics prepared by this method are promising candidates for a wide range of general applications.

Details

International Journal of Clothing Science and Technology, vol. 24 no. 2/3
Type: Research Article
ISSN: 0955-6222

Keywords

Article
Publication date: 1 July 2004

Bouchaib Bahli and Younes Benslimane

Wireless computing, as a way of providing mobile services, has been growing steadily during the past few years. While wireless communications offer organizations and users…

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Abstract

Wireless computing, as a way of providing mobile services, has been growing steadily during the past few years. While wireless communications offer organizations and users many benefits such as portability, flexibility, increased productivity, and lower installation costs; on the other hand, risks inherent and exacerbated by wireless connectivity are widely reported, wherein networks are open to intruders who may cause unwanted consequences to an organization's information resources. Hence, understanding these risks will help protect against unforeseen threats, delays and costs. This paper aims at the development of a taxonomy for wireless computing risks. Six levels are identified including risks associated with the users, mobile devices, wireless networks, wireless applications, the Internet and the corporate gateway. The findings show that there is a need for systematic studies on wireless risk assessment and management. The implications of these findings for both researchers and practitioners are discussed.

Details

Information Management & Computer Security, vol. 12 no. 3
Type: Research Article
ISSN: 0968-5227

Keywords

Article
Publication date: 2 July 2020

Yihua Dou, Yufei Li, Yinping Cao, Yang Yu, Jiantao Zhang and Lin Zhang

To maintain the well integrity, the strength and sealing ability of premium connection should be in the safe scope. ISO 13679 is widely used for evaluating the ability of…

Abstract

Purpose

To maintain the well integrity, the strength and sealing ability of premium connection should be in the safe scope. ISO 13679 is widely used for evaluating the ability of tubing and casing connection all over the world. FE is adopted to simulate the ISO 13679 tests.

Design/methodology/approach

Because of the disadvantage of experiment such as long period, high cost and high requirement on the facility, considering the convenience and universality of finite element method, as well as the contacting nonlinearity and material nonlinearity, three-dimensional finite element model of a certain type of premium connection is established with the consideration of helix angle. The loads exerted on the premium connection are the loads in series B test and thermal cycle test of ISO 13679. The distributions of Von Mises stress and contact pressure in various cases were studied.

Findings

The results showed that the bending load has a great influence on the distribution of Von Mises stress and contact pressure for premium connection. The Von Mises stress and contact pressures on the sealing surface are smaller on the tension side and greater on the compression side. With increasing axial compression load, the contact pressures on the tension side are too small, which may lead to sealing failure. The influence of temperature on the performance of premium connection cannot be ignored when choosing or designing premium connections. Both the Von Mises stress and contact pressure decrease slightly during a period of thermal cycle. Although the performance of the premium connection is good in a period of thermal cycle, its performance in a long period should be evaluated. Finite element simulation can effectively simulate the ISO 13679 test procedure and obtain the stress and contact pressure distribution. It can be used as a reference for evaluating the performance of premium connections.

Originality/value

Considering the convenience and universality of finite element method, as well as the contacting nonlinearity and material nonlinearity, three-dimensional finite element model of a certain type of premium connection is established with the consideration of helix angle.

Details

International Journal of Structural Integrity, vol. 12 no. 1
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 5 June 2017

Samira Farivar, Ofir Turel and Yufei Yuan

Social commerce websites have emerged as new platforms which integrate social media features with traditional commerce aspects to enhance users’ purchasing experience. The…

2203

Abstract

Purpose

Social commerce websites have emerged as new platforms which integrate social media features with traditional commerce aspects to enhance users’ purchasing experience. The purpose of this paper is to examine the role of social factors such as trust toward site members in determining users’ trust and risk evaluations, and the role of social commerce use habit in attenuating users’ rational risk and trust considerations for developing purchase intentions.

Design/methodology/approach

Relying on the risk deterrence perspective and rational decision-making models involving trust and habit, this study proposes a set of hypotheses which are tested through analyzing survey data using structural equation modeling techniques.

Findings

Results show that commerce risk deters purchasing intentions; trust toward the social commerce website increases users’ purchasing intentions; and trust toward the site members indirectly increases purchasing intentions. Moreover, trust toward site members reduces perceived commerce risk. Findings also show that habit modulates trust and risk effects on use decisions in this context; habit moderates (weakens) the relationships between commerce risk and purchase intentions and between trust toward the social commerce site and purchase intentions.

Originality/value

This study extends theories on decision making in social settings such as in the case of social commerce. It does so by accounting for unique modulating effects of habit in social settings in which social aspects such as trust in other members and risk are unique and important.

Details

Internet Research, vol. 27 no. 3
Type: Research Article
ISSN: 1066-2243

Keywords

Article
Publication date: 9 October 2018

Willard Navicha, Yufei Hua, Kingsley George Masamba, Xiangzhen Kong and Caimeng Zhang

The purpose of this paper is to evaluate the changes in descriptive sensory properties and overall consumer acceptability of soymilk prepared from roasted soybeans.

Abstract

Purpose

The purpose of this paper is to evaluate the changes in descriptive sensory properties and overall consumer acceptability of soymilk prepared from roasted soybeans.

Design/methodology/approach

In total, 12 purposively selected post graduate students majoring in Food Science conducted descriptive sensory analysis after being trained for 18 h in sensory analysis, while 75 untrained students conducted consumer acceptability test of soymilk prepared by roasting soybeans at a temperature of 110°C for 20, 40, 60, 80 and 100 min and at 120°C for 20 min.

Findings

Results have revealed that roasting soybeans improved sensory properties by significantly (p<0.05) decreasing the objectionable green, beany flavours and increasing sweet taste, viscosity and roasted flavour. Furthermore, results from the principal component analysis revealed that aroma and sweet taste were the most critical sensory attributes. In addition, it was found out that soymilk samples prepared by roasting soybeans at 110°C for 40 and 60 min and at 120°C for 20 min were significantly more acceptable than the control soymilk.

Research limitations/implications

The participants in this study were from one locality and predominantly soybean consuming community and therefore there is need to conduct the study in a different locality in order to validate the study findings.

Practical implications

The study can assist small scale processors that might not have access to lipoxygenase-free soybeans and other technologies for improving the quality of soymilk.

Social implications

The study can be used as a guide for connecting the food processers with the external world of consumption.

Originality/value

For the first time, the study findings have demonstrated that controlled soybean roasting can be a useful strategy for improving soymilk sensory properties and consumer acceptability. The findings in this study can be usefully used in the quality control of soy bean-based products.

Details

British Food Journal, vol. 120 no. 12
Type: Research Article
ISSN: 0007-070X

Keywords

Article
Publication date: 4 October 2019

Weidong Zhu, Yufei Tian, Xue Hu, Quan Ku and Xiaoya Dai

The purpose of this paper is to reveal the pattern between government innovation funding and enterprise value creation. Many factors, including government innovation…

Abstract

Purpose

The purpose of this paper is to reveal the pattern between government innovation funding and enterprise value creation. Many factors, including government innovation funding, R&D ability, corporate governance and some company characteristics significantly affected the efficiency of firm value creation.

Design/methodology/approach

This paper proposed a novel methodology based on clustering-rough sets to explore the characteristics of enterprise value creation behavior, and map the relationship between government innovation funding and enterprise value creation. The agglomerative hierarchical clustering (AHC) algorithm were used to classify firm performance and get two types of value creation efficiencies and to discretize condition attributes because the rough set theory cannot deal with continuous attributes. This paper utilized the rough sets method to realize data mining and get rules of government innovation funding and enterprise value creation.

Findings

R&D ability, proportion of independent directors, remuneration of directors, operating revenue, number of employees, price-earnings ratio, quick ratio, capital intensity and ROA were important to identify firm value creation efficiency when government funded the firms. Firms of high level of government innovation funding, high lagged R&D ratio, high remuneration of directors, low price-earnings ratio, low quick ratio, moderate capital intensity and high ROA were more likely to have high efficiency of value creation.

Originality/value

Since China implemented the innovation-driven development strategy, facilitating enterprise innovation has become an important way to achieve high-quality economic growth. With constantly increasing of Chinese government innovation funding, studying on the effect of government innovation funding on firm’s value creation is significant to improve the efficiency of government resource allocation. It is valuable to reveal the pattern between government innovation funding and enterprise value creation based on the value added theory. The rules obtained could be used to provide decision-making support to improve the efficiency of government innovation funding and prevent waste of government resources effectively.

Details

Kybernetes, vol. 49 no. 2
Type: Research Article
ISSN: 0368-492X

Keywords

Article
Publication date: 1 February 2021

Yufei Ma, Shuangxin Wang, Dingli Yu and Kaihua Zhu

This paper aims to enable the unmanned aerial vehicles to inspect the surface condition of wind turbine in close range when the global positioning system signal is not…

Abstract

Purpose

This paper aims to enable the unmanned aerial vehicles to inspect the surface condition of wind turbine in close range when the global positioning system signal is not reliable, and further improve its intelligence. So a visual-inertial odometry with point and line features is developed.

Design/methodology/approach

Visual front-end combining point and line features, as well as its purification strategies, are first presented to improve the robustness of feature tracking in low-textured scene and rapidity of segment detector. Additionally, the inertial measurement is integrated between keyframes as constrain to reduce tracking error existed in visual-only system. Second, the graph-based visual-inertial back-end is constructed. To parameterize line features effectively, the infinite line representation not sensitive to outdoor light is employed, in which Plücker and Cayley are selected for line re-projection and nonlinear optimization. Furthermore, Jacobians of the line re-projection errors are analytically derived for better accuracy.

Findings

Experiments are performed in various scenes of the wind farm. The results demonstrate that the tight-coupled visual-inertial odometry with point and line features is more precise on all the samples than conventional algorithms in complex wind farm environments. Additionally, the constructed line feature map can be used in the following research for autonomous navigation.

Originality/value

The proposed visual-inertial odometry works robustly in strong electromagnetic interference, low-textured and illumination-change wind farm.

Details

Industrial Robot: the international journal of robotics research and application, vol. 48 no. 2
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 18 April 2022

Qi Chen, Ofir Turel and Yufei Yuan

Controversial information systems (IS) represent a unique context in which certain members of a user's social circle may endorse the use of a system while others object to…

Abstract

Purpose

Controversial information systems (IS) represent a unique context in which certain members of a user's social circle may endorse the use of a system while others object to it. The purpose of this paper is to explore the simultaneous and often conflicting roles of such positive and negative social influences through social learning and ambivalence theories in shaping user adoption intention of a representative case of controversial IS, namely online dating services (ODS).

Design/methodology/approach

The model was tested with two empirical studies using structural equation modeling techniques. The data of these studies were collected from 451 (Study 1) and 510 (Study 2) single individuals (i.e. not in a relationship).

Findings

(1) Positive social influence has a stronger impact on perceived benefits and adoption intention, while negative social influence exerts a greater impact on perceived risks; (2) positive and negative social influences affect adoption intention toward ODS differently, through benefit and risk assessments; and (3) ambivalence significantly negatively moderates the effects of social influences on adoption.

Originality/value

This study enriches and extends the IS use, ambivalence theory, prospect theory, and social learning theory research streams. Furthermore, this study suggests that it is necessary to focus on not only the oft-considered positive but also negative social influences in IS research.

Details

Information Technology & People, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0959-3845

Keywords

Article
Publication date: 18 February 2021

Hao Chen, Ofir Turel and Yufei Yuan

Electronic waste (e-waste) such as discarded computers and smartphones may contain large amounts of confidential data. Improper handling of remaining information in…

Abstract

Purpose

Electronic waste (e-waste) such as discarded computers and smartphones may contain large amounts of confidential data. Improper handling of remaining information in e-waste can, therefore, drive information security risk. This risk, however, is not always properly assessed and managed. The authors take the protection motivation theory (PMT) lens of analysis to understand intentions to protect one's discarded electronic assets.

Design/methodology/approach

By applying structural equation modeling, the authors empirically tested the proposed model with survey data from 348 e-waste handling users.

Findings

Results highlight that (1) protection intention is influenced by the perceived threat of discarding untreated e-waste (a threat appraisal) and self-efficacy to treat the discarded e-waste (a coping appraisal) and (2) optimism bias plays a dual-role in a direct and moderating way to reduce the perceived threat of untreated e-waste and its effect on protection intentions.

Originality/value

Results support the assertions and portray a unique theoretical account of the processes that underline people's motivation to protect their data when discarding e-waste. As such, this study explains a relatively understudied information security risk behavior in the e-waste context, points to the role of optimism bias in such decisions and highlights potential interventions that can help to alleviate this information security risk behavior.

Details

Information Technology & People, vol. 35 no. 2
Type: Research Article
ISSN: 0959-3845

Keywords

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