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Article

Subing Liu, Yin Chunwu and Cao Dazhi

The purpose of this paper is to provide a new recursive GM (1,1) model based on forgetting factor and apply it to the modern weapon and equipment system.

Abstract

Purpose

The purpose of this paper is to provide a new recursive GM (1,1) model based on forgetting factor and apply it to the modern weapon and equipment system.

Design/methodology/approach

In order to distinguish the contribution of new and old data to the grey prediction model with new information, the authors add forgetting factor to the objective function. The purpose of the above is to realize the dynamic weighting of new and old modeling data, and to gradually forget the old information. Second, the recursive estimation algorithm of grey prediction model parameters is given, and the new information is added in real time to improve the prediction accuracy of the model.

Findings

It is shown that the recursive GM (1,1) model based on forgetting factor can achieve both high effectiveness and high efficiency.

Originality/value

The paper succeeds in proposing a recursive GM (1,1) model based on forgetting factor, which has high accuracy. The model is applied to the field of modern weapon and equipment system and the result the model is better than the GM(1,1) model. The experimental results show the effectiveness and the efficiency of the prosed method.

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Article

Ying Ma, Kang Ping, Chen Wu, Long Chen, Hui Shi and Dazhi Chong

The Internet of Things (IoT) has attracted a lot of attention in both industrial and academic fields for recent years. Artificial intelligence (AI) has developed rapidly…

Abstract

Purpose

The Internet of Things (IoT) has attracted a lot of attention in both industrial and academic fields for recent years. Artificial intelligence (AI) has developed rapidly in recent years as well. AI naturally combines with the Internet of Things in various ways, enabling big data applications, machine learning algorithms, deep learning, knowledge discovery, neural networks and other technologies. The purpose of this paper is to provide state of the art in AI powered IoT and study smart public services in China.

Design/methodology/approach

This paper reviewed the articles published on AI powered IoT from 2009 to 2018. Case study as a research method has been chosen.

Findings

The AI powered IoT has been found in the areas of smart cities, healthcare, intelligent manufacturing and so on. First, this study summarizes recent research on AI powered IoT systematically; and second, this study identifies key research topics related to the field and real-world applications.

Originality/value

This research is of importance and significance to both industrial and academic fields researchers who need to understand the current and future development of intelligence in IoT. To the best of authors’ knowledge, this is the first study to review the literature on AI powered IoT from 2009 to 2018. This is also the first literature review on AI powered IoT with a case study of smart public service in China.

Details

Library Hi Tech, vol. 38 no. 1
Type: Research Article
ISSN: 0737-8831

Keywords

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Article

Desheng Zhang, Weidong Shi, Dazhi Pan and Guangjian Zhang

– The purpose of this paper is to predict the unstable cavitation shedding flow around a 2D Clark-y hydrofoil.

Abstract

Purpose

The purpose of this paper is to predict the unstable cavitation shedding flow around a 2D Clark-y hydrofoil.

Design/methodology/approach

The paper studies Partially Averaged Navier-Stokes (PANS) model which was employed in the two-phase flow with a homogeneous cavitation model.

Findings

Maximum density ratio affects the mass transfer rate between the liquid and the vapor significantly. The cavitating flow predicted by PANS model can resolve more turbulent scales by decreasing the parameter fk.

Originality/value

The accuracy of numerical prediction is improved by increasing the maximum density ratio and decreasing fk.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 25 no. 4
Type: Research Article
ISSN: 0961-5539

Keywords

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Article

Mohammad Yaghoub Abdollahzadeh Jamalabadi

This paper aims to investigate the use of a piezo fan in an enclosure on wall heat transfer and thermal boundary layer profile in constant wall temperature situation.

Abstract

Purpose

This paper aims to investigate the use of a piezo fan in an enclosure on wall heat transfer and thermal boundary layer profile in constant wall temperature situation.

Design/methodology/approach

The governing partial differential equations of mass, momentum and energy in addition to boundary conditions are solved by lattice Boltzmann method. The problem is solved numerically using D2Q9 population's model and Bhatnagar–Gross–Krook collision model with a code written in MATLAB.

Findings

The effects of Prandtl number (Pr) and the frequency of piezo fan vibrations are critically investigated on the hydrothermal characteristics of the square cavity. The mesh independency study and the validation of the proposed model are accomplished with numerical results of Ghia et al. (1982) and analytical solution of pure conduction very good agreement is found between present results and benchmark findings. Generally, with increasing beam frequency, the heat removal from heat source increased. It is found that, for all Prandtl numbers, wall Nusselt number will increase with the increase of the beam frequency. This enhancement is more intense in higher Prandtl number.

Originality/value

Based on these results, the use of piezo fan in an enclosure can be classified as standalone as well as heat sink integrated cooling solution.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 30 no. 1
Type: Research Article
ISSN: 0961-5539

Keywords

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