Peng Cai, Pingjie Zhang, Xiong Xiao, Wenneng Yang, Xiaohan Wu, Lingli Ni and Fei Zheng
The purpose of this paper is to investigate the effect of mullite on the mechanical properties and friction of carbon fiber (CF)-reinforced friction material.
Abstract
Purpose
The purpose of this paper is to investigate the effect of mullite on the mechanical properties and friction of carbon fiber (CF)-reinforced friction material.
Design/methodology/approach
CF-reinforced friction materials with varying content of mullite were fabricated by hot press molding, and then the tribological properties were tested on the MRH-3-type tribometer under ambient conditions with the ring-on-block configuration.
Findings
The experimental results indicated that the addition of mullite increased the density and compressive strength of friction material. However, the flexural strength of friction material decreased by 16% with the addition of 15 Wt.% mullite. The friction coefficient was proportional to the mullite content. Friction material with 12.5 Wt.% mullite showed the highest friction stability under different loads, whereas friction material with 10 Wt.% mullite exhibited the highest friction stability under different sliding speeds.
Originality/value
By boosting the resistance to deformation under load and increasing the specific heat capacity, mullite contributed significantly to the friction stability of the friction material.
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Peng Xia, Kunjie Li, Fangui Zeng, Xiong Xiao, Jianliang Zhang, Jianhua Xiang and Beilei Sun
Pyrolysis for coal gas generation changes the composition, pore structure, permeability and adsorption capacity of coal. This work aims to discuss the utilization of coal…
Abstract
Purpose
Pyrolysis for coal gas generation changes the composition, pore structure, permeability and adsorption capacity of coal. This work aims to discuss the utilization of coal pyrolysis on enhancing coalbed methane (CBM) production in the Gujiao area, Shanxi province, China.
Design/methodology/approach
This research was conducted mainly by the methods of thermogravimetry mass spectrometry (TG-MS) analysis, liquid nitrogen adsorption experiment and methane isothermal adsorption measurement.
Findings
The results can be concluded as that 400-700°C is the main temperature range for generating CH4. Pore volume and specific surface area increase with increasing temperature; however, the proportion of micro pore, transition pore and macro pore has no difference. The optimum temperature for enhancing CBM production should be letter than 600°C because the sedimentation of tar and other products will occupy some pores and fissures after 600°C.
Originality/value
Here in, to accurately recognize the suitable maximum temperature for heating development, a method enhancing CBM production, TG-MS, was adopted to analyze the products and the weight loss of coals with different ranks in the Gujiao area at temperature of 30-1,100°C. And then the pore structure, porosity, permeability, methane adsorption capacity and thermal maturity of coals during pyrolysis were investigated with increased temperature from 30°C to 750°C. On these bases, the favorable condition for enhancing CBM production and the thermal evolution of coal were recognized.
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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.
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.
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Dan Xiong, Junhao Xiao, Huimin Lu, Zhiwen Zeng, Qinghua Yu, Kaihong Huang, Xiaodong Yi and Zhiqiang Zheng
The purpose of this paper is to design intelligent robots operating in such dynamic environments like the RoboCup Middle-Size League (MSL). In the RoboCup MSL, two teams of five…
Abstract
Purpose
The purpose of this paper is to design intelligent robots operating in such dynamic environments like the RoboCup Middle-Size League (MSL). In the RoboCup MSL, two teams of five autonomous robots play on an 18- × 12-m field. Equipped with sensors and on-board computers, each robot should be able to perceive the environment, make decision and control itself to play the soccer game autonomously.
Design/methodology/approach
This paper presents the design of our soccer robots, participating in RoboCup MSL. The mechanical platform, electrical architecture and software framework are discussed separately. The mechanical platform is designed modularly, so easy maintainability is achieved; the electronic architecture is built on industrial standards using PC-based control technique, which results in high robustness and reliability during the intensive and fierce MSL games; the software is developed upon the open-source Robot Operating System (ROS); thus, the advantages of ROS such as modularity, portability and expansibility are inherited.
Findings
Based on this paper and the open-source hardware and software, the MSL robots can be re-developed easily to participate in the RoboCup MSL. The robots can also be used in other research and education fields, especially for multi-robot systems and distributed artificial intelligence. Furthermore, the main designing ideas proposed in the paper, i.e. using a modular mechanical structure, an industrial electronic system and ROS-based software, provide a common solution for designing general intelligent robots.
Originality/value
The methodology of the intelligent robot design for highly competitive and dynamic RoboCup MSL environments is proposed.
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Zhihuai Xiao, Jiang Guo, Hongtao Zeng, Pan Zhou and Shuqing Wang
The purpose of this paper is to develop a new hybridized controller based on fuzzy reasoning and neural network (NN) for hydropower generator unit (HGU).
Abstract
Purpose
The purpose of this paper is to develop a new hybridized controller based on fuzzy reasoning and neural network (NN) for hydropower generator unit (HGU).
Design/methodology/approach
The approach contains fuzzy neural networks controller (FNNC), RBF network identification (RBFNI) and HGU system. FNNC may give control value to control HGU via fuzzy NN reasoning and computing according to HGU rotate speed error and error varying rate. RBFNI is used to identify the character of HGU system and predict its output. FNNC may adjust parameters and member function according to the identifying and predictive outcome of RBFNI.
Findings
Sees that the hybridized control system is feasible and stable, and the controlling performance of the hybridized system is superior to conventional fuzzy controller.
Research limitations/implications
The theoretical proof of stability of the proposed scheme still remains to be studied. Accessibility and availability of membership functions and control rules is also a limitation applied.
Practical implications
The main advantage of the proposed method is that FNNC has reasoning, learning, and optimizing capability which can control effectively HGU. This will be useful for control engineers to control complex industrial plants.
Originality/value
The paper proposes new combined approach to optimal control of HGU using FNNC, and it is aimed at operational researches and engineers, especially those who dealt with HUG controller.
Details
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Yi-Cheng Chen and Yen-Liang Chen
In this “Info-plosion” era, recommendation systems (or recommenders) play a significant role in finding interesting items in the surge of online digital activity and e-commerce…
Abstract
Purpose
In this “Info-plosion” era, recommendation systems (or recommenders) play a significant role in finding interesting items in the surge of online digital activity and e-commerce. The purpose of this paper is to model users' preference evolution to recommend potential items which users may be interested in.
Design/methodology/approach
A novel recommendation system, namely evolution-learning recommendation (ELR), is developed to precisely predict user interest for making recommendations. Differing from prior related methods, the authors integrate the matrix factorization (MF) and recurrent neural network (RNN) to effectively describe the variation of user preferences over time.
Findings
A novel cumulative factorization technique is proposed to efficiently decompose a rating matrix for discovering latent user preferences. Compared to traditional MF-based methods, the cumulative MF could reduce the utilization of computation resources. Furthermore, the authors depict the significance of long- and short-term effects in the memory cell of RNN for evolution patterns. With the context awareness, a learning model, V-LSTM, is developed to dynamically capture the evolution pattern of user interests. By using a well-trained learning model, the authors predict future user preferences and recommend related items.
Originality/value
Based on the relations among users and items for recommendation, the authors introduce a novel concept, virtual communication, to effectively learn and estimate the correlation among users and items. By incorporating the discovered latent features of users and items in an evolved manner, the proposed ELR model could promote “right” things to “right” users at the “right” time. In addition, several extensive experiments are performed on real datasets and are discussed. Empirical results show that ELR significantly outperforms the prior recommendation models. The proposed ELR exhibits great generalization and robustness in real datasets, including e-commerce, industrial retail and streaming service, with all discussed metrics.
Details
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Qiubin Huang and Mengyuan Xiong
This paper aims to examine the effects of managerial ability (MA) on the likelihood and the timeliness of goodwill impairment and explore whether the desirable effect of MA vary…
Abstract
Purpose
This paper aims to examine the effects of managerial ability (MA) on the likelihood and the timeliness of goodwill impairment and explore whether the desirable effect of MA vary with the degree of agency problems.
Design/methodology/approach
The authors propose a unified framework to simultaneously examine the effects of MA on the likelihood and the timeliness of goodwill impairment by incorporating a market-based impairment indicator (denoted as BTM), MA and the interaction of BTM with MA to this study’s regression model to account for the likelihood of goodwill impairment. BTM addresses the timeliness of goodwill impairment.
Findings
This study finds that firms with higher MA have lower likelihood of goodwill impairment, and such firms are more likely to recognize goodwill impairment in a timely manner when the underlying value of goodwill is economically impaired. This desirable effect of MA is more pronounced in non-state-owned enterprise (SOEs) and firms without chief executive officer (CEO) duality.
Practical implications
Firms can reduce the losses arising from goodwill impairment by enhancing the ability of their management teams combined with improved corporate governance structure.
Originality/value
This paper provides novel insights on understanding the role of MA in not only reducing the likelihood but also enhancing the timeliness of goodwill impairment. The findings help advance the upper echelons theory by uncovering the heterogenous effects of executives with different levels of ability.
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Ou Wang, Simon Somogyi and Richard Ablett
The purpose of this paper is to explore Chinese consumers’ perceptions towards a luxury seafood – lobster, and identify the important perceptions that influence Chinese consumers’…
Abstract
Purpose
The purpose of this paper is to explore Chinese consumers’ perceptions towards a luxury seafood – lobster, and identify the important perceptions that influence Chinese consumers’ general image of lobster. It also recognises Chinese consumer segments based on their perceptions towards lobster.
Design/methodology/approach
The data were collected through an online survey (n=882, in two Chinese cities: Shanghai and Qingdao). The surveys explored consumer’s perceptions and general image of lobster. Descriptive analysis, partial least squares regression and cluster analysis were conducted for data analyses.
Findings
Findings show that the most important perceptions regarding lobster by Chinese consumers are umami, delicious, high in protein, expensive, nutritious, upscale, red colour and bring back appetite. Chinese consumers’ general image of lobster is positively linked to perception items, such as delicious, western flavour, umami, nutritious, high in protein, enjoy, upscale and appetite; and is negatively linked to perception items: spicy/hot, Chinese flavour and risk in illness. Three consumer segments are identified: western-flavour-lovers (35.4 per cent), Chinese-flavour-lovers (32.8 per cent) and negative-believers (31.8 per cent). Significant differences were recognised in the socio-demographic distribution among these three segments including, city, income, marital status, educational level, occupation and age.
Originality/value
This is the first study to present information regarding consumers’ perceptions, general image and segments towards luxury seafood in the world’s largest East-Asian country – China. The findings from this study can help global seafood marketers and exporters to better understand Chinese consumers which should assist them in developing effective marketing strategies for their luxury seafood products in this major market.
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Xin Feng, Xu Wang and Mengxia Qi
In the era of the digital economy, higher demands are placed on versatile talents, and the cultivation of students with innovative and entrepreneurial abilities has become an…
Abstract
Purpose
In the era of the digital economy, higher demands are placed on versatile talents, and the cultivation of students with innovative and entrepreneurial abilities has become an important issue for the further development of higher education, thus leading to extensive and in-depth research by many scholars. The study summarizes the characteristics and patterns of dual-innovation education at different stages of development, hoping to provide a systematic model for the development of dual-innovation education in China and make up for the shortcomings.
Design/methodology/approach
This paper uses Citespace software to visualize and analyze the relevant literature in CNKI and Web of Science databases from a bibliometric perspective, focusing on quantitative analysis in terms of article trends, topic clustering, keyword co-linear networks and topic time evolution, etc., to summarize and sort out the development of innovation and entrepreneurship education research at home and abroad.
Findings
The study found that the external characteristics of the literature published in the field of bi-innovation education in China and abroad are slightly different, mainly in that foreign publishers are more closely connected and have formed a more stable ecosystem. In terms of research hotspots, China is still in a critical period of reforming its curriculum and teaching model, and research on the integration of specialization and creative education is in full swing, while foreign countries focus more on the cultivation of students' entrepreneurial awareness and the enhancement of individual effectiveness. In terms of cutting-edge analysis, the main research directions in China are “creative education”, “new engineering”, “integration of industry and education” and “rural revitalization”.
Originality/value
Innovation and entrepreneurship education in China is still in its infancy, and most of the studies lack an overall overview and comparison of foreign studies. Based on the econometric analysis of domestic and foreign literature, this paper proposes a path for domestic innovation and entrepreneurship education reform that can make China's future education reform more effective.
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Rasheda Weaver and Chyanne Lanae Blakey
This study aims to outline the importance of distinguishing between different types of societal crises and the role that plays in how social enterprises may respond to crises at…
Abstract
Purpose
This study aims to outline the importance of distinguishing between different types of societal crises and the role that plays in how social enterprises may respond to crises at hand.
Design/methodology/approach
Previous literature is used to distinguish between various types of societal crises discussed in the study. Social enterprise responses to the COVID-19 pandemic, economic recession and the racial uprising in the USA that all erupted at the start of the 2020 decade are explored to illustrate the need for different responses to each.
Findings
The origin and manifestation of crises differ in that they may have public health, natural, economic or even intentionally man-made origins. In addition, in times of crisis, social enterprises must be prepared to innovate, adapt or at least manage the effects of one or more crises on their organizations. These innovations may be social, technology or economic innovations.
Research limitations/implications
This study contributes to knowledge about the role and value of social enterprise as a tool for addressing societal issues. The three types of crises explored in this paper will likely reoccur and evolve to manifest in new ways. As such, it is imperative that research on the efficacy of social enterprises during times of crisis are conducted to inform practice, policy and future research.
Practical implications
This study aims to inform and encourage institutions, particularly social enterprises, to recognize that “winter always comes.” Crises always happen in life and how organizations respond to such crises will differ based on the type of crisis at hand. This study particularly contributes to knowledge by emphasizing the need for social enterprises to think about both economic uncertainty and the role they play in addressing crises in the long-term, not just when they occur.
Originality/value
To the best of the authors’ knowledge, this study is one of the first to explore the role and value of social enterprises as a tool for combatting major social crises such as racism, pandemics and recessions.