Xiao-Bo Wang, Wen-Jie Xu, Bing-Yin Zhang and Qi-Cheng Sun
Rock-fill dams are embankments of compacted free-draining granular earth containing an impervious zone. Earth utilized in such dams often contains a high percentage of large…
Abstract
Purpose
Rock-fill dams are embankments of compacted free-draining granular earth containing an impervious zone. Earth utilized in such dams often contains a high percentage of large particles – hence the term rock-fill. Mass stability of these dams results from friction and particle interactions rather than through a cementing agent binding the particles together. However, high-stress conditions and prolonged exposure to the elements can severely damage rock-fill. Therefore, understanding and modeling rock-fill breakage is important for dam engineering. The purpose of this paper is to improve discontinuous deformation analysis (DDA) techniques for modeling rock-fill breakage, proving the new method using simulations of spherical particle crushing.
Design/methodology/approach
This work models rock-fill as bonded ellipsoid particles, and develops an improved DDA method to model the breakage of particle assemblies. The paper starts by describing the principles of three-dimensional DDA for spherical particles, and then derives the submatrices for normal contact, shear contact, and frictional force. The new algorithm incorporates a bond model with a revised open-close iteration algorithm into the DDA method to simulate particle crushing. To validate the improved DDA method, calculated particle contacts and movements are validated against theoretical results. Finally, this work performs a series of point-loading experimental tests for cement ellipsoid particles of both high and low compression strengths, with the test results compared against the results from corresponding DDA simulations.
Findings
In particle crushing tests, the force and displacement show an approximately linear relationship until the crushing point, at which point low compression ellipsoid particles split into several large pieces while the high-compression particles break into many small fragments. The DDA simulation results are in good agreement with the crushing tests, demonstrating the validity of the DDA method for solving particle crushing problems. Although the improved DDA model is applicable to rock-fill particle crushing studies, some issues remain, particularly in increasing calculation efficiency and performing large-scale computations and long real-time simulations. Future research should address these issues.
Originality/value
A bond model with a revised open-close iteration algorithm is incorporated into the DDA method. The simulated results shed insight into rock-fill crushing mechanisms, an element of concern in engineering practices.
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Xiao Bo Liang, Xinghua Qu, YuanJun Zhang, Lianyin Xu and Fumin Zhang
Laser absolute distance measurement has the characteristics of high precision, wide range and non-contact. In laser ranging system, tracking and aiming measurement point is the…
Abstract
Purpose
Laser absolute distance measurement has the characteristics of high precision, wide range and non-contact. In laser ranging system, tracking and aiming measurement point is the precondition of automatic measurement. To solve this problem, this paper aims to propose a novel method.
Design/methodology/approach
For the central point of the hollow angle coupled mirror, this paper proposes a method based on correlation filtering and ellipse fitting. For non-cooperative target points, this paper proposes an extraction method based on correlation filtering and feature matching. Finally, a visual tracking and aiming system was constructed by combining the two-axis turntable, and experiments were carried out.
Findings
The target tracking algorithm has an accuracy of 91.15% and a speed of 19.5 frames per second. The algorithm can adapt to the change of target scale and short-term occlusion. The mean error and standard deviation of the center point extraction of the hollow Angle coupling mirror are 0.20 and 0.09 mm. The mean error and standard deviation of feature points matching for non-cooperative target were 0.06 mm and 0.16 mm. The visual tracking and aiming system can track a target running at a speed of 0.7 m/s, aiming error mean is 1.74 pixels and standard deviation is 0.67 pixel.
Originality/value
The results show that this method can achieve fast and high precision target tracking and aiming and has great application value in laser ranging.
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Kaveh Abhari, Elizabeth J. Davidson and Bo Xiao
The importance of co-innovation platforms has been well established, but a valid and reliable instrument to measure the affordances of these platforms for co-innovation behavior…
Abstract
Purpose
The importance of co-innovation platforms has been well established, but a valid and reliable instrument to measure the affordances of these platforms for co-innovation behavior has not yet been reported in the literature. A robust, validated instrument to measure co-innovation platform affordances (PAs) will facilitate the conduct of studies across different platforms and contribute to enhanced understanding of co-innovation behaviors, outcomes, and platform design. The purpose of this paper is to conceptualize co-innovation PAs, develop a reliable measurement instrument capturing critical facets of co-innovation, namely ideation, collaboration, and communication, and validate the instrument.
Design/methodology/approach
The construct of PAs was conceptualized based on the findings from two case studies of co-innovation networks and the key characteristics of social mediating technology affordances. The measurement items newly developed via a case study underwent a two-round exploratory analysis to ensure face validity and content validity. The resulting instrument was subjected to a pilot study and a field study to establish the necessary reliability and validity.
Findings
The findings of the study reveal that co-innovation PAs have three distinctive components, namely ideation, collaboration, and communication. Furthermore, the results of the study suggest that PAs are most appropriately operationalized as a second-order construct comprising all three components. The empirical results from the field study show a high degree of confidence in both translation validity and criterion-related validity.
Originality/value
Drawing from co-innovation and affordances literature, this study develops and validates a general instrument to measure co-innovation PAs. The result is a reliable and parsimonious instrument with 12 items. The authors believe that the instrument can contribute significantly to future empirical investigations of co-innovation behavior on virtual platforms.
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Tao Han, Bo Xiao, Xi-Sheng Zhan, Jie Wu and Hongling Gao
The purpose of this paper is to investigate time-optimal control problems for multiple unmanned aerial vehicle (UAV) systems to achieve predefined flying shape.
Abstract
Purpose
The purpose of this paper is to investigate time-optimal control problems for multiple unmanned aerial vehicle (UAV) systems to achieve predefined flying shape.
Design/methodology/approach
Two time-optimal protocols are proposed for the situations with or without human control input, respectively. Then, Pontryagin’s minimum principle approach is applied to deal with the time-optimal control problems for UAV systems, where the cost function, the initial and terminal conditions are given in advance. Moreover, necessary conditions are derived to ensure that the given performance index is optimal.
Findings
The effectiveness of the obtained time-optimal control protocols is verified by two contrastive numerical simulation examples. Consequently, the proposed protocols can successfully achieve the prescribed flying shape.
Originality/value
This paper proposes a solution to solve the time-optimal control problems for multiple UAV systems to achieve predefined flying shape.
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Dong Wu, Xiao‐bo Wu and Hao‐jun Zhou
The purpose of this paper is to investigate the relationship between international expansion and firm performance in an emerging market.
Abstract
Purpose
The purpose of this paper is to investigate the relationship between international expansion and firm performance in an emerging market.
Design/methodology/approach
The paper firstly explores the relationship between internationalization and firm performance, then investigates the roles of diversification, and examines how diversification moderates the relationship between internationalization and firm performance. For this purpose, panel data on 318 Chinese listed manufacturing firms during the period 1999‐2008 were utilized. Three groups of samples of high, medium and low levels of diversified manufacturing firms were obtained. Statistical techniques of fixed‐effects panel data model yielded an interesting pattern of findings. On the basis of these results, the paper then discusses the implications for the international expansion of Chinese firms.
Findings
At high and low levels of internationalization, internationalization is negatively associated with firm performance, but at medium levels of internationalization, greater internationalization is accompanied by higher performance. Product diversification negatively moderates the relationship between internationalization and performance. As product diversification increases, the relationship between internationalization and performance changes from a horizontal S‐curve in firms with low levels of diversification to a U‐curve in moderately diversified firms and eventually to an equilibrium level in highly diversified firms. The initial stage of the horizontal S‐curve of internationalization and performance declines markedly in Chinese manufacturing firms as a whole, therefore it is by no means easy for Chinese firms to undertake internationalization.
Research limitations/implications
These findings do suggest that managers need to take a long‐term view of internationalization and make a commitment to internationalization.
Originality/value
This is the first paper of its kind to empirically validate the relationship between internationalization, firm performance and diversification in China. It is intended to make a contribution to theoretical research on international business in an emerging market.
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Kaveh Abhari, Elizabeth J. Davidson and Bo Xiao
Co-innovation networks face the important challenge of cultivating collective innovation outcomes while also preserving the interests of individual contributors. Addressing this…
Abstract
Purpose
Co-innovation networks face the important challenge of cultivating collective innovation outcomes while also preserving the interests of individual contributors. Addressing this challenge requires first understanding and then managing individuals’ perception of co-innovation risks. The purpose of this paper is to provide a meaningful approach to addressing co-innovation risks using a valid and reliable model to assess actors’ perception of risk and examine its effect on actor co-innovation behavior.
Design/methodology/approach
The construct of co-innovation risk from the actor’s perspective was conceptualized based on a case study of a co-innovation network. The measurement items underwent a pilot study and a field study to establish the necessary reliability and validity. This paper also empirically assesses a nomological network that illustrates the effect of risk on co-innovation behavior with a moderating effect of prior experience.
Findings
Co-innovation actors perceived four different individual risks: time, social, intellectual property right, and financial. The empirical results from the field study demonstrate a high degree of confidence in both translation validity and criterion-related validity. Negative effects of perceived co-innovation risk on actors’ continuous intention to ideate, collaborate, and communicate in co-innovation were evident, but prior experience moderated these relationships.
Originality/value
Drawing from co-innovation and individual risk literature, this study develops and validates a general instrument to measure co-innovation risk from the actors’ perspective. The result is a reliable and parsimonious instrument with 15 items, which contributes significantly to future empirical investigations of co-innovation behavior on virtual platforms.
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Fei Liu, Bo Xiao, Eric T.K. Lim and Chee-Wee Tan
By delineating electronic word-of-mouth (e-WOM) into numerical rating and opinionated review, the purpose of this paper is to advance a research model that articulates how the…
Abstract
Purpose
By delineating electronic word-of-mouth (e-WOM) into numerical rating and opinionated review, the purpose of this paper is to advance a research model that articulates how the provision of e-WOM can aid in alleviating consumers’ distrust of online service providers, a key determinant in the former’s adoption of the latter. The authors also endeavor to uncover the role gender plays in moderating the aforementioned relationship between e-WOM and distrust.
Design/methodology/approach
The research model was validated via a field survey administered on 115 college students and faculty members, who had been exposed to a custom-developed online restaurant review website. SmartPLS 2.0.M3 was employed to verify both the measurement and structural properties of the research model.
Findings
Distrust reduces male consumers’ perceptions of usefulness and ease of use toward an online service provider while increasing their adoption intention. For their female counterparts, distrust reduces both perceived ease of use and adoption intention for an online service provider. Additionally, for male consumers, only opinionated review aids in alleviating distrust. Conversely, both numerical rating and opinionated review aid in alleviating the distrust of female consumers. Moreover, in contrast to their female counterparts, male consumers are less susceptible to the influence of cognitive dissonance between numerical rating and opinionated review.
Research limitations/implications
This study integrates distrust with the technology acceptance model (TAM) in an attempt to gain a deeper appreciation of technology acceptance behavior. Furthermore, this study builds on the confirmation bias theory to delineate e-WOM into numerical rating and opinionated review in order to better explicate variations in how males and females react to these two distinct forms of e-WOM. Consistent with the cognitive dissonance theory, the distinction between numerical rating and opinionated review enables further exploration of the impact of cognitive dissonance between these two forms of e-WOM on male and female consumers’ distrust of online service providers. Finally, this study unveils contrasting conflict resolution strategies adopted by male and female consumers to cope with cognitive dissonance in e-WOM.
Practical implications
Findings from this study yield prescriptions for practitioners in terms of how e-WOM can be harnessed to alleviate consumers’ distrust of online service provider. Whereas it is crucial for online service providers to draw on opinionated review to reduce distrust for male consumers, numerical rating should be emphasized for female consumers. This study also sensitizes practitioners to the drawback of providing both numerical rating and opinionated review at the same time due to the potential for cognitive dissonance.
Originality/value
This study is the first to: position distrust within the well-accepted TAM in order to enrich the understanding of technology acceptance behavior; testify to the importance of delineating between numerical rating and opinionated review due to the possibility of cognitive dissonance between these two distinct forms of e-WOM, as well as; uncover contrasting conflict resolution strategies adopted by male and female consumers to cope with cognitive dissonance in accordance with the confirmation bias theory.
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Fei Liu, Bo Xiao, Eric T.K. Lim and Chee-Wee Tan
The purpose of this paper is to advance product appeal and website appeal as focal psychological mechanisms that can be invoked by business-to-consumer e-commerce sites to…
Abstract
Purpose
The purpose of this paper is to advance product appeal and website appeal as focal psychological mechanisms that can be invoked by business-to-consumer e-commerce sites to mitigate problems of information asymmetry via signaling to bolster consumers’ purchase intention under the influence of trust.
Design/methodology/approach
Survey approach was employed to validate the research model.
Findings
Website appeal partially mediates the positive effect of product appeal on consumers’ purchase intention. Trust in e-commerce sites not only increases purchase intention directly, but it also reinforces the positive relationship between website appeal and purchase intention while attenuating the positive relationship between product appeal and purchase intention. Service content quality, search delivery quality, and enjoyment are confirmed as positive antecedents of website appeal whereas diagnosticity and justifiability are established as positive antecedents of product appeal.
Research limitations/implications
This study not only delineates product and website appeal as complementary drivers of consumer purchase on e-commerce sites, but it also derives five signals that aid in bolstering both product and website appeal. Trust is revealed to exert a moderating influence on the impact of product and website appeal on purchase intention.
Practical implications
Practitioners should prioritize their resource allocation to enhance qualities most pertinent to product and website appeal. E-commerce sites should offer product-oriented functionalities to facilitate product diagnosticity and reassure consumers of their purchase decisions.
Originality/value
This study distinguishes between product and website appeal as well as between their respective antecedents. It also uncovers how trust can alter the effects of both website and product appeal on consumers’ purchase intention.
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Shengzhi Chen, Minghua Zhu, Qing Zhang, Xuesong Cai and Bo Xiao
The differential magnetic gradient tensor system is usually constructed from the three-axis magnetic sensor array. While the effects of measurement error, sensor performance and…
Abstract
Purpose
The differential magnetic gradient tensor system is usually constructed from the three-axis magnetic sensor array. While the effects of measurement error, sensor performance and baseline distance on localization performance of such systems have been widely reported, the research about the effect of spatial design of sensor array is less presented. This paper aims to provide a spatial design method of sensor array and corresponding optimization strategy to localization based on magnetic tensor gradient to get the optimum design of the sensor array. Based on the results of simulation, magnetic localization systems constructed from the proposed array and the traditional array have been built to carry out a localization experiment. The results of experiment have verified the effectiveness of magnetic localization based on the proposed array.
Design/methodology/approach
The authors focus on the localization of the magnetic target based on magnetic gradient by using three-axis magnetic sensor array and combine a design method with corresponding optimization strategy to get the optimum design of the sensor array.
Findings
This paper provides an array design and optimization method for magnetic target localization based on magnetic gradient to improve the localization performance.
Originality/value
In this paper, the authors focus on the magnetic localization based on magnetic gradient by using three-axis magnetic sensors and study the effect of the spatial design of sensor array on localization performance.
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Ying Liu, Yongmei Liu and Bo Sophia Xiao
This study explored whether crowdsourcing work characteristics are associated with perceived work effort in competitive crowdsourcing markets. The study also investigated the…
Abstract
Purpose
This study explored whether crowdsourcing work characteristics are associated with perceived work effort in competitive crowdsourcing markets. The study also investigated the important contextual variables and internal mechanisms related to perceived work effort.
Design/methodology/approach
A questionnaire was posted as a crowdsourcing task on China's Time Fortune website. Data from 231 valid questionnaires were analyzed using SmartPLS 3.
Findings
Crowdsourcing workers' intrinsic and extrinsic motivations were significantly and positively correlated with their perceived work effort. Task autonomy and feedback were significantly and positively correlated with intrinsic motivation. Skill variety, task significance, task identity, and task clarity had no significant correlations with intrinsic motivation. However, task clarity was significantly and positively correlated with perceived work effort. Moreover, the relationship between workers' trust in task requesters and perceived work effort was fully mediated by intrinsic motivation.
Originality/value
This study extended the job characteristic model into the virtual competitive crowdsourcing market. The authors verified the relationship between task clarity/trust in task requesters and workers' motivation and perceived work effort.