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Article
Publication date: 18 April 2017

Lin Deng, Junjie Liang, Yun Zhang, Huamin Zhou and Zhigao Huang

Lattice Boltzmann method (LBM) has made great success in computational fluid dynamics, and this paper aims to establish an efficient simulation model for the polymer injection…

391

Abstract

Purpose

Lattice Boltzmann method (LBM) has made great success in computational fluid dynamics, and this paper aims to establish an efficient simulation model for the polymer injection molding process using the LBM. The study aims to validate the capacity of the model for accurately predicting the injection molding process, to demonstrate the superior numerical efficiency in comparison with the current model based on the finite volume method (FVM).

Design/methodology/approach

The study adopts the stable multi-relaxation-time scheme of LBM to model the non-Newtonian polymer flow during the filling process. The volume of fluid method is naturally integrated to track the movement of the melt front. Additionally, a novel fractional-step thermal LBM is used to solve the convection-diffusion equation of the temperature field evolution, which is of high Peclet number. Through various simulation cases, the accuracy and stability of the present model are validated, and the higher numerical efficiency verified in comparison with the current FVM-based model.

Findings

The paper provides an efficient alternative to the current models in the simulation of polymer injection molding. Through the test cases, the model presented in this paper accurately predicts the filling process and successfully reproduces several characteristic phenomena of injection molding. Moreover, compared with the popular FVM-based models, the present model shows superior numerical efficiency, more fit for the future trend of parallel computing.

Research limitations/implications

Limited by the authors’ hardware resources, the programs of the present model and the FVM-based model are run on parallel up to 12 threads, which is adequate for most simulations of polymer injection molding. Through the tests, the present model has demonstrated the better numerical efficiency, and it is recommended for the researcher to investigate the parallel performance on even larger-scale parallel computing, with more threads.

Originality/value

To the authors’ knowledge, it is for the first time that the lattice Boltzmann method is applied in the simulation of injection molding, and the proposed model does obviously better in numerical efficiency than the current popular FVM-based models.

Details

Engineering Computations, vol. 34 no. 2
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 4 September 2019

Xing Zhang, Shan Liu, Li Wang, Yajun Zhang and Jiayin Wang

Mobile health service (MHS) can provide users with convenient health services and information to reduce their medical costs from aging or other health issues. Previous studies…

2372

Abstract

Purpose

Mobile health service (MHS) can provide users with convenient health services and information to reduce their medical costs from aging or other health issues. Previous studies confirm the underdevelopment of the Chinese MHS. The purpose of this paper is to analyze the factors that affect the intention to use MHS.

Design/methodology/approach

This paper develops a research model that integrates personal health differences with theory of planned behavior (TPB) and protection motivation theory (PMT). This model is empirically tested using data from 494 valid questionnaires. Structural equation modeling is used to test the hypotheses.

Findings

Perceived vulnerability to disease, perceived severity of disease, response efficacy and self-efficacy positively affect attitude, thereby exerting a positive influence on the behavioral intention to use MHS. Subjective norms also influence users’ behavioral intention. Personal health status and personal health value have quasi-moderating effects on the relationship between attitude and behavioral intention.

Originality/value

This paper presents an early attempt to conceptualize and validate a research model of MHS acceptance by integrating TPB and PMT in a complementary manner. The integrated model provides a holistic view of people’s intention to use MHS by considering health threat beliefs, individual role (i.e. attitude and self-efficacy) and social influences (i.e. subjective norms). Furthermore, this research highlights the role of two individual health characteristics (i.e. personal health status and personal health value) in MHS adoption. These new findings are beneficial toward an in-depth understanding of technology adoption in the MHS context.

Details

Online Information Review, vol. 44 no. 1
Type: Research Article
ISSN: 1468-4527

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Article
Publication date: 16 October 2009

Xinping Xiao and Fuqin Li

The purpose of this paper is to deal with the ill‐conditioned problem for the non‐equigap GM(1,1) control model by using the method of multiple transformations.

135

Abstract

Purpose

The purpose of this paper is to deal with the ill‐conditioned problem for the non‐equigap GM(1,1) control model by using the method of multiple transformations.

Design/methodology/approach

Owing to noises and interferences from both inside and outside of the system, many control systems contain unequal intervals and sharp variation which may result in undesirable systems instability. In order to ensure the stability and efficiency of grey forecasting control model, the data transformation for a raw series is an important and useful method for enhancing accuracy and improving ill‐condition of the non‐equigap GM(1,1) model.

Findings

This paper discusses the quantitative relations between the multiple transformation and the parameters of the non‐equigap GM(1,1) model in detail, and studies the effect of the multiple transformation on the condition number of the non‐equigap GM(1,1) model.

Research limitations/implications

Accessibility and availability of data are the main limitations based on which model will be applied.

Practical implications

Choosing an appropriate multiple of transformation cannot only eliminate dimension, lessen computation and maintain high accuracy, but also largely reduce the condition number of the model and improve the ill‐condition of non‐equigap GM(1,1) model effectively.

Originality/value

This paper seems to be the first to discuss the stability problems for the non‐equigap GM(1,1) model.

Details

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

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Article
Publication date: 16 July 2024

Himani Dahiya and A.K. Saini

The purpose of this paper is to identify and examine the determinants of individuals’ attitude (ATT) and behavioural intention (BI) to use dietary and fitness mobile apps in the…

186

Abstract

Purpose

The purpose of this paper is to identify and examine the determinants of individuals’ attitude (ATT) and behavioural intention (BI) to use dietary and fitness mobile apps in the context of India.

Design/methodology/approach

The present study develops a conceptual model by incorporating additional variables such as health consciousness (HC), perceived trust (PT), social influence (SI) and personal innovativeness (PI) into the original technology acceptance model (TAM). These constructs were extracted from existing theories and literature on technology adoption, individuals’ health beliefs and personality traits. The conceptual model has been empirically tested and validated by applying structural equation modelling using STATA version 15. The data was collected from both potential and actual users of dietary and fitness mobile apps through a structured questionnaire, both online and manually. Following a convenience sampling approach, a total of 450 respondents from Delhi national capital region (NCR) were contacted, of which 264 valid responses were considered for final analysis.

Findings

The results revealed that of all the factors predicting individuals’ “attitude” towards the use of dietary and fitness apps, perceived usefulness was found to be the most significant followed by PI and PT. Similarly, behavioural “intention to use” was most strongly determined by an individual’s attitude towards the usage of dietary and fitness apps followed by SI.

Practical implications

Findings of the study offer meaningful insights and implications for academics and practitioners. Mobile app developers and service providers can gain an understanding of the consumer’s behaviour towards adoption of dietary and fitness apps and improve the app’s utility, service quality, interface and features in view of the empirically validated determinants of such behaviour. Furthermore, it is essential for the service providers to undertake promotional efforts to not only create awareness of the availability of such apps but also at the same time educate people on the needs, functionalities and utilities they offer. Also, to gain a wider acceptance of the apps, focus on more communication and gamification/ entertainment features is required.

Originality/value

This study adds value by identifying the factors from varied perspectives (technical, social, health and personal) impacting individuals’ attitude and BI to use an innovative health intervention i.e. dietary and fitness mobile apps in a developing economy. Furthermore, the study proved the robustness of extended TAM in the area of healthcare. Lastly, this paper is among the few papers in the Indian context that assessed the adoption of dietary and fitness mobile apps.

Details

Journal of Indian Business Research, vol. 16 no. 3
Type: Research Article
ISSN: 1755-4195

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Article
Publication date: 1 February 2016

Sifeng Liu, Yingjie Yang, Naiming Xie and Jeffrey Forrest

The purpose of this paper is to summarize the progress in grey system research during 2000-2015, so as to present some important new concepts, models, methods and a new framework…

1898

Abstract

Purpose

The purpose of this paper is to summarize the progress in grey system research during 2000-2015, so as to present some important new concepts, models, methods and a new framework of grey system theory.

Design/methodology/approach

The new thinking, new models and new methods of grey system theory and their applications are presented in this paper. It includes algorithm rules of grey numbers based on the “kernel” and the degree of greyness of grey numbers, the concept of general grey numbers, the synthesis axiom of degree of greyness of grey numbers and their operations; the general form of buffer operators of grey sequence operators; the four basic models of grey model GM(1,1), such as even GM, original difference GM, even difference GM, discrete GM and the suitable sequence type of each basic model, and suitable range of most used grey forecasting models; the similarity degree of grey incidences, the closeness degree of grey incidences and the three-dimensional absolute degree of grey incidence of grey incidence analysis models; the grey cluster model based on center-point and end-point mixed triangular whitenization functions; the multi-attribute intelligent grey target decision model, the two stages decision model with grey synthetic measure of grey decision models; grey game models, grey input-output models of grey combined models; and the problems of robust stability for grey stochastic time-delay systems of neutral type, distributed-delay type and neutral distributed-delay type of grey control, etc. And the new framework of grey system theory is given as well.

Findings

The problems which remain for further studying are discussed at the end of each section. The reader could know the general picture of research and developing trend of grey system theory from this paper.

Practical implications

A lot of successful practical applications of the new models to solve various problems have been found in many different areas of natural science, social science and engineering, including spaceflight, civil aviation, information, metallurgy, machinery, petroleum, chemical industry, electrical power, electronics, light industries, energy resources, transportation, medicine, health, agriculture, forestry, geography, hydrology, seismology, meteorology, environment protection, architecture, behavioral science, management science, law, education, military science, etc. These practical applications have brought forward definite and noticeable social and economic benefits. It demonstrates a wide range of applicability of grey system theory, especially in the situation where the available information is incomplete and the collected data are inaccurate.

Originality/value

The reader is given a general picture of grey systems theory as a new model system and a new framework for studying problems where partial information is known; especially for uncertain systems with few data points and poor information. The problems remaining for further studying are identified at the end of each section.

Details

Grey Systems: Theory and Application, vol. 6 no. 1
Type: Research Article
ISSN: 2043-9377

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Article
Publication date: 1 October 2024

Beatrice Audifasi Nyallu, Xiaopeng Deng and Melckzedeck Michael Mgimba

Knowledge loss (KL) is still an unfortunate fact, causing many challenges, including poor organisational performance, despite prior efforts to investigate knowledge retention…

116

Abstract

Purpose

Knowledge loss (KL) is still an unfortunate fact, causing many challenges, including poor organisational performance, despite prior efforts to investigate knowledge retention methods. Therefore, this study identifies early approaches to combat KL and poor organisational performance, shifting focus on employee personality traits.

Design/methodology/approach

Grounded on the social exchange theory (SET) cross-section data from 400 Chinese construction knowledge employees were used to investigate the role of internal work locus of control (IWLC) on job rotation (JR), KL and organisational performance. The data were analysed through IBM SPSS Statistics 25 and SmartPLS 4 software.

Findings

The results demonstrated that IWLC minimises KL and positively influences JR. Then, JR negatively influences KL and decreases in organisational performance. The negative mediating effect of JR in the relationship between IWLC, KL and decreased organisational performance were also found. Finally, KL proved to positively influence a decrease in organisational performance.

Research limitations/implications

This study contributes to the new understanding of individual behaviour and its influence on organisational outcome variables. Specifically, for ultimate KL prevention and organisational performance improvement, an organisation should understand its employees' behaviours to establish progressive collective learning and knowledge sharing.

Practical implications

This study contributes to the new understanding of individual behaviour and its influence on organisational outcome variables. Specifically, for ultimate KL prevention and organisational performance improvement, an organisation should understand its employees’ behaviours to establish progressive collective learning and knowledge sharing.

Originality/value

This study is the first attempt to explore the influence of personality traits in the early minimisation of KL, particularly the role of IWLC and JR in combating KL and improving organisational performance.

Details

Engineering, Construction and Architectural Management, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0969-9988

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Article
Publication date: 16 October 2009

Nai‐Ming Xie and Si‐Feng Liu

The purpose of this paper is to study the parameters' properties of GM(n, h) model on the basis of multiple transformation and the relationship of GM(n, h) model and other grey…

120

Abstract

Purpose

The purpose of this paper is to study the parameters' properties of GM(n, h) model on the basis of multiple transformation and the relationship of GM(n, h) model and other grey models.

Design/methodology/approach

Multiple transformation property of parameters is important to construct a grey model. However, there is no research on the property of GM(n, h) model, therefore it is meaningful to study the relationship between GM(n, h) model and other grey models.

Findings

The multiple transformation property of parameters of GM(n, h) model is recognized. The parameters' value is dependent on multiple transformation value. The values of simulative and predicative are only dependent to the multiple transformation of the main variable and independent to other variables.

Research limitations/implications

The properties of other grey models could be obtained by analyzing the property of GM(n, h) model.

Practical implications

It is a very useful result for constructing a grey model.

Originality/value

This paper discusses multiple transformation property of GM(n, h) model and the relationship between the GM(n, h) model and other grey models. These grey models are put into a common model and the affections that parameters' multiple transformation caused to the model are studied.

Details

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

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Article
Publication date: 24 September 2021

Xue Deng and Yingxian Lin

The weighted evaluation function method with normalized objective functions is used to transform the proposed multi-objective model into a single objective one, which reflects the…

106

Abstract

Purpose

The weighted evaluation function method with normalized objective functions is used to transform the proposed multi-objective model into a single objective one, which reflects the investors' preference for returns, risks and social responsibility by adjusting the weights. Finally, an example is given to illustrate the solution steps of the model and the effectiveness of the algorithm.

Design/methodology/approach

Based on the possibility theory, assuming that the future returns of each asset are trapezoidal fuzzy numbers, a mean-variance-Yager entropy-social responsibility model is constructed including piecewise linear transaction costs and risk-free assets. The model proposed in this paper includes six constraints, the investment proportion sum, the non-negativity proportion, the ceiling and floor, the pre-assignment, the cardinality and the round lot constraints. In addition, considering the special round lot constraint, the proposed model is transformed into an integer programming problem.

Findings

The effects of different constraints and transaction costs on the effective frontier of the portfolio are analyzed, which not only assists investors to make decisions close to their expectations by setting appropriate parameters but also provides constructive suggestions through the overall performance of each asset.

Originality/value

There are two improvements in the improved particle swarm optimization algorithm: one is that the complex constraints are specifically satisfied by using a renewable 0–1 random constraint matrix and random scaling factors instead of fixed ones; the other is eliminating the particles with poor fitness and randomly adding some new particles that satisfy all the constraints to achieve the goal of global search as much as possible.

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Article
Publication date: 7 August 2009

Sifeng Liu, Jeffrey Forrest and Robert Vallee

The purpose of this paper is to present the scientific background from which grey systems theory came into being, the astonishing progress that grey systems theory has made in the…

1189

Abstract

Purpose

The purpose of this paper is to present the scientific background from which grey systems theory came into being, the astonishing progress that grey systems theory has made in the world of learning and its wide‐ranging applications in the entire spectrum of science.

Design/methodology/approach

The grey uncertainty is compared with other kinds of uncertainty such as stochastic uncertainty, unascertainty, fuzzy and rough uncertainty.

Findings

The advances in grey systems theory and its various successful applications are introduced individually by algorithms of grey numbers and grey algebraic systems, grey dynamic models and grey predictions, grey optimization analysis for decision making, grey control models.

Research limitations/implications

Many scientific theories require the unremitting efforts of several generations of people and have gone through hundreds of years before reaching maturity and perfection. Grey systems theory is still in its growth period. So, it is unavoidable that there exist immature and imperfect parts in the theory.

Originality/value

Grey systems theory is a new method for studying problems of uncertainty with few data points and poor information. This new theory studies small samples and systems with poor information, which have partial information known, partial information unknown. It describes adequately and monitors effectively systems' operations and evolutions through extracting valuable information from the little known information. Grey systems theory comes into being along with the development of modern systems science and uncertainty systems theories and methods. It is also a result of deepened perceptivity about uncertain systems.

Details

Kybernetes, vol. 38 no. 7/8
Type: Research Article
ISSN: 0368-492X

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Article
Publication date: 1 May 2000

Xu‐Dong Ji

Outlines the history of accounting in China and reviews the literature published in English on the full range of Chinese accounting issues. Summarizes the contents of three books…

1375

Abstract

Outlines the history of accounting in China and reviews the literature published in English on the full range of Chinese accounting issues. Summarizes the contents of three books, refers to sections in other books and analyses journal articles by period, journal, research topic and research method. Argues that this accounting research has historical, academic and practical value,believes it will continue to improve and calls for greater use of more rigid research methodologies in this area.

Details

Managerial Finance, vol. 26 no. 5
Type: Research Article
ISSN: 0307-4358

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