Yunfei Liu, Jun Lv and Xiaowei Gao
The purpose of this paper is to introduce a new method called simultaneous elimination and back-substitution method (SEBSM) to solve a system of linear equations as a new finite…
Abstract
Purpose
The purpose of this paper is to introduce a new method called simultaneous elimination and back-substitution method (SEBSM) to solve a system of linear equations as a new finite element method (FEM) solver.
Design/methodology/approach
In this paper, a new technique assembling the global stiffness matrix will be proposed and meanwhile the direct method SEBSM will be applied to solve the equations formed in FEM.
Findings
The SEBSM solver for FEM with the present assembling technique has distinct advantages in both computational time and memory space occupation over the conventional methods, such as the Gauss elimination and LU decomposition methods.
Originality/value
The developed solver requires less memory space no matter the coefficient matrix is a typical sparse matrix or not, and it is applicable to both symmetric and unsymmetrical linear systems of equations. The processes of assembling matrix and dealing with constraints are straightforward, so it is convenient for coding. Compared to the previous solvers, the proposed solver has favorable universality and good performances.
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Mengxia Jiang, Yang Liu, Yuxiong Xue, Guangbao Shan, Jun Lv and Mairui Huang
This paper aims to systematically study the effects of reflow temperature and SAC0307 (SAC) content on the micromorphology and mechanical properties of Sn58Bi-xSAC0307 composite…
Abstract
Purpose
This paper aims to systematically study the effects of reflow temperature and SAC0307 (SAC) content on the micromorphology and mechanical properties of Sn58Bi-xSAC0307 composite solder joints to meet the requirements of high integration and low-temperature packaging of devices and provide references for the application of composite solder joints.
Design/methodology/approach
Sn58Bi and SAC0307 solder paste was mechanically mixed in different proportions to prepare Sn58Bi-xSAC0307/ENIG solder joints. The thermal properties, microstructure and mechanical properties of the composite solder joints were studied.
Findings
As SAC content in the solder increases, the balling temperature of SnBi-SAC solder gradually increases. The addition of SAC alloy reduces the grain size of large Bi-rich phase, and there are small-sized dispersed Bi and Ag3Sn particles in the bulk solder. The intermetallic compounds composition of the SnBi-xSAC/ENIG solder joint changes from Ni3Sn4 to (Ni, Cu)3Sn4 and (Cu, Ni)6Sn5 with SAC increasing. As the soldering temperature increases, the strength of all solder joints shows a rising trend. Among them, the shear strength of SnBi-20SAC solder joints at a reflow temperature of 150°C is approximately 37 MPa. As the reflow temperature increases to 250°C, the shear strength of solder joints increases to approximately 67 MPa.
Originality/value
This study provides a reference for the optimization of low-temperature solder composition and soldering process under different package designs.
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Zhi-Jun Lv, Qian Xiang, Jian-guo Yang and Long-di Cheng
Textile production is a very complex industrial process, whose planning still depends on experts' knowledge and experience. With traditional techniques, a great many process…
Abstract
Textile production is a very complex industrial process, whose planning still depends on experts' knowledge and experience. With traditional techniques, a great many process parameters have to be repeatedly computed and the optimization of process parameters is also getting more and more difficult. However the proliferation of a huge mass of data from real production has been creating many new opportunities for those working in textile science, engineering and business. The field of data mining (DM) and knowledge discovery from database (KDD) has emerged as a new discipline in engineering and computer science. This paper investigates data mining methods from the industrial database, and presents a novel DM-based intelligent model (DMIM) for worsted process decisions through an integral application of case-based reasoning (CBR) and artificial neural network (ANN) techniques. First, from the rich existing process database, CBR is able to retrieve and recommend a similar process case as a process template; then, by means of modification on these parameters in the existing cases, ANN model is used to predict the yarn quality and make the best process decision. The basic concept and system modeling are presented in this paper. An applied case with DMIM is also given to demonstrate that the best process decision can be made and important process parameters such as those for raw materials can be optimized.
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Zhang Yong‐de, Jiang Jin‐gang, Lv Pei‐jun and Wang Yong
It is not an easy and simple task to manufacture a complete denture with high quality. Traditionally, it often needs a medical expert with experience and hand‐on skill, due to the…
Abstract
Purpose
It is not an easy and simple task to manufacture a complete denture with high quality. Traditionally, it often needs a medical expert with experience and hand‐on skill, due to the manual way of denture manufacturing. The purpose of this paper is to implement the multi‐manipulator tooth‐arrangement robot system that can fully automate the denture manufacturing process.
Design/methodology/approach
A novel complete denture manufacturing mechanism is designed, which is based on the multi‐manipulator and dental arch generator. The visual tooth‐arrangement and robot control software is developed in VC++6.0. Preliminary experiments on tooth‐arrangement have been conducted using the proposed multi‐manipulator tooth‐arrangement robot prototype system.
Findings
The multi‐manipulator tooth‐arrangement robot prototype system can automatically design and manufacture a set of complete denture that fit a patient by visual tooth‐arrangement and robot control software according to the patient's jaw arch parameters.
Research limitations/implications
The implication of research is that it is feasible that the manufacture strategy of complete denture fulfilled by multi‐manipulator tooth‐arrangement robot. The limitation of research is that it is difficult to realize coordinate control.
Originality/value
The traditional manual method which makes complete denture by medical personal experience will be changed after the multi‐manipulator tooth‐arrangement robot system is manufactured, and adjustment to each tooth position and orientation will be realized by this system.
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The purpose of this paper is to better understand the dramatic transformation of Las Vegas from a local watering hole to a world renowned entertainment city, and to offer…
Abstract
Purpose
The purpose of this paper is to better understand the dramatic transformation of Las Vegas from a local watering hole to a world renowned entertainment city, and to offer predictions of what this ever-changing city might become in the future.
Design/methodology/approach
A series of turning points in Las Vegas’ history are presented in a chronological manner, highlighting how external forces have played a role in shaping the city into what it is today. These external forces are then used as the underlying reasoning for a series of scenarios, signposts informing predictions detailing what might happen to Las Vegas in the future.
Findings
The development of Las Vegas has been influenced by a wide range of external factors, from geology, government, organized crime, business visionaries, large corporations and the economy. The continued influence of these factors could lead to drastically divergent outcomes from the loss of the city to a new golden age.
Originality/value
This paper identifies turning points that have helped to shape the development of Las Vegas, and in doing so encourages researchers to consider future scenarios grounded in the underlying dynamics of the turning points.
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Jun Wu, Chaoyong Wu, Yaqiong Lv, Chao Deng and Xinyu Shao
Rolling bearings based on rotating machinery are one of the most widely used in industrial applications because of their low cost, high performance and robustness. The purpose of…
Abstract
Purpose
Rolling bearings based on rotating machinery are one of the most widely used in industrial applications because of their low cost, high performance and robustness. The purpose of this paper is to describe how to identify degradation condition of rolling bearing and predict its fault time in big data environment in order to achieve zero downtime performance and preventive maintenance for the rolling bearing.
Design/methodology/approach
The degradation characteristic parameters of rolling bearings including intrinsic mode energy and failure frequency were, respectively, extracted from the pre-processed original vibration signals using EMD and Hilbert transform. Then, Spearman’s rank correlation coefficient and PCA were used to obtain the health index of the rolling bearing so as to detect the appearance of degradations. Furthermore, the degradation condition of the rolling bearings might be identified through implementing the monotonicity analysis, robustness analysis and degradation analysis of the health index.
Findings
The effectiveness of the proposed method is verified by a case study. The result shows that the proposed method can be applied to monitor the degradation condition of the rolling bearings in industrial application.
Research limitations/implications
Further experiment remains to be done so as to validate the effectiveness of the proposed method using Apache Hadoop when massive sensor data are available.
Practical implications
The paper proposes a methodology for rolling bearing condition monitoring representing the steps that need to be followed. Real-time sensor data are utilized to find the degradation characteristics.
Originality/value
The result of the work presented in this paper form the basis for the software development and implementation of condition monitoring system for rolling bearings based on Hadoop.
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Guy Assaker and Peter O’Connor
This chapter reviews the methods available to hospitality and tourism researchers to perform moderation analysis with continuous variables in partial least squares structural…
Abstract
This chapter reviews the methods available to hospitality and tourism researchers to perform moderation analysis with continuous variables in partial least squares structural equation modeling (PLS-SEM), with the objective of enhancing understanding and encouraging the use of these techniques in future papers. The product term method is presented first, followed by an empirical example/application in the context of hospitality and tourism. Two extensions, namely the two-stage approach that can help cope with formative and higher-order constructs, and the orthogonalizing approach that can help generate more accurate results and overcome multicollinearity among tourism variables in the presence of a continuous moderator variable, are then presented and discussed. The chapter concludes by presenting guidelines and recommendations for improving the use of interaction effects in analyses of tourism variables, as well as highlighting ongoing developments in both the product term method and PLS-SEM software.
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Jun Yu, Chaowu Xie and Songshan Huang
This study aims to identify a value co-creation framework for live streaming through tourism scenes (LStTS). It also clarifies the value attributes of LStTS and makes an empirical…
Abstract
Purpose
This study aims to identify a value co-creation framework for live streaming through tourism scenes (LStTS). It also clarifies the value attributes of LStTS and makes an empirical test.
Design/methodology/approach
The study used a mixed-method approach. In Study 1, a total of 12,216 pieces of viewers’ comments and ten web news reports were coded and analyzed employing a grounded theory approach. In Study 2, data were collected from 587 Douyin e-commerce users. Exploratory factor analysis and partial least squares structural equation modeling were used to test the value co-creation framework of LStTS.
Findings
In Study 1, six value attributes in three categories were identified based on a content analysis of viewers’ comments. In Study 2, a three-order factorial model of value co-creation in LStTS was identified and tested.
Research limitations/implications
Our study is limited by the preponderance of female respondents in the sample and the unique nature of the research context.
Practical implications
Merchants and streamers should consider whether there is a fit between the merchandise and the tourism scene when selecting the tourism scene for live streaming marketing; they can select novel and beautiful natural tourism scenes to attract viewers. Detailed and comprehensive product information should be provided in the process of live streaming marketing and sharing with consumers.
Originality/value
The novelty of our study lies in the provision of a new value co-creation framework in LStTS, which offers a theoretical basis for analyzing the value of the tourism scene in live streaming marketing.
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The equipment manufacturing industry, as a strategic industry of China, is experiencing a transition from imitative innovation to independent innovation. The achievements of…
Abstract
Purpose
The equipment manufacturing industry, as a strategic industry of China, is experiencing a transition from imitative innovation to independent innovation. The achievements of independent innovation have not been as good as could have been expected. Based on evolutionary economics, the purpose of this paper is to explore the evolutionary path of the two innovation modes, respectively, and analyze the internal and external factors that hinder the mutation from imitative innovation routine to independent innovation routine. According to the results of the evolutionary game model, several policy suggestions are proposed to promote the transition from imitative innovation to independent innovation.
Design/methodology/approach
This paper is based on the concepts of evolutionary economics. Routine, mutation, path dependence and selection are included in the analysis of the evolutionary path of the two innovation modes. Especially, the evolutionary game model of innovation modes selection is established to explain how internal and external conditions work in the transition.
Findings
The paper explores the evolutionary path of the transition from imitative innovation to independent innovation in the equipment manufacturing industry of China, and analyses the obstacles and factors (internal path dependence, and the lack of benefit incentive and external mutation conditions such as fiscal support and intellectual property protection) that hinder the mutation from imitative innovation routine to independent innovation routine. The results of the evolutionary game model show that the pursuit of the benefit (innovation return or the profit), as an internal mutation condition, is the most fundamental motivation for independent innovation, while policy incentives, as the external mutation conditions, have a significant impact on the evolutionary transition. According to the results, several policy suggestions are proposed to promote the transition from imitative innovation to independent innovation.
Originality/value
Taking the equipment manufacturing industry as a particular object, this paper tries to explain the evolutionary path and the obstacle factors of the transition from imitative innovation to independent innovation from the perspective of evolutionary economics, involving routine, mutation, path dependence, selection, and so on. The evolutionary game model of innovation modes selection is established to investigate the influence of these factors.