Qiuping Wang, Subing Liu and Haixia Yan
Due to high efficiency and low carbon of natural gas, the consumption of natural gas is increasing rapidly, and the prediction of natural gas consumption has become the focus. The…
Abstract
Purpose
Due to high efficiency and low carbon of natural gas, the consumption of natural gas is increasing rapidly, and the prediction of natural gas consumption has become the focus. The purpose of this paper is to employ a prediction technique by combining grey prediction model and trigonometric residual modification for predicting average per capita natural gas consumption of households in China.
Design/methodology/approach
The GM(1,1) model is utilised to obtain the tendency term, then the generalised trigonometric model is used to catch the periodic phenomenon from the residual data of GM(1,1) model for improving predicting accuracy.
Findings
The case verified the view of Xie and Liu: “When the value of a is less, DGM model and GM(1,1) model can substitute each other.” The combination of the GM(1,1) and the trigonometric residual modification technique can observably improve the predicting accuracy of average per capita natural gas consumption of households in China. The mean absolute percentage errors of GM(1,1) model, DGM(1,1), unbiased grey forecasting model, and TGM model in ex post testing stage (from 2013 to 2015) are 32.5510, 33.5985, 36.9980, and 5.2996 per cent, respectively. The TGM model is suitable for the prediction of average per capita natural gas consumption of households in China.
Practical implications
According to the historical data of average per capita natural gas consumption of households in China, the authors construct GM(1,1) model, DGM(1,1) model, unbiased grey forecasting model, and GM(1,1) model with trigonometric residual modification. The accuracy of TGM is the best. TGM helps to improve the accuracy of GM(1,1).
Originality/value
This paper gives a successful practical application of grey model GM(1,1) with the trigonometric residual modification, where the cyclic variations exist in the residual series. The case demonstrates the effectiveness of trigonometric grey prediction model, which is helpful to understand the modeling mechanism of trigonometric grey prediction model.
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Zhaofei Wang, Zihao Weng, Jing Wang and Qiuping Wang
COVID-19 has aggregated the need for a non-contact medical logistic system. A non-contact robot with self-navigation ability has greatly enhanced the efficiency of the medical…
Abstract
Purpose
COVID-19 has aggregated the need for a non-contact medical logistic system. A non-contact robot with self-navigation ability has greatly enhanced the efficiency of the medical logistic system. This paper aims to design a new medical logistics robot system for the complex environment of hospitals with dynamic obstacles.
Design/methodology/approach
Targeting a medical logistics robot system for a large-scale hospital environment, this study proposed a dynamic obstacle avoidance system to reduce the robot’s delay time as well as frequent route switching. In the algorithm, this study proposed a new loop closure detection with an artificial correction factor. Moreover, this study presented enhanced 3D object detection, improving detection accuracy in hospital environments.
Findings
Experimental results confirm that the robot can move along its global path and reach its destination without colliding with stationary or moving obstacles.
Originality/value
The medical logistics robot system has safe and stable performance in real hospital scenarios. The implementation verifies that the robot has effectiveness and reliability in both hardware and software design.
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Jieren Guan, Shuhu Luo, Xinfeng Kan, Chao Chen and Qiuping Wang
The purpose of this study is to assess the effects of fused filament fabrication (FFF) printing parameters on the surface quality and dimensional accuracy of FFF-fabricated copper…
Abstract
Purpose
The purpose of this study is to assess the effects of fused filament fabrication (FFF) printing parameters on the surface quality and dimensional accuracy of FFF-fabricated copper green parts using the appropriate filaments. The orthogonal experiments were implemented and the errors in length, width and height were measured and analyzed. The results of range analysis and variance analysis indicated the orders of effect factors. Dissolvent debinding combined with thermal debinding was adopted to remove the binders inside the green part by calculating debinding rate. The influence mechanism of sintering temperatures on the microstructure and shrinkage was elaborated.
Design/methodology/approach
The extrusion-based FFF in manufacturing copper parts can overcome shortcomings for high reflectivity and heat dissipation in laser powder bed fusion process at cost-saving and materials saving. This study makes an attempt to prepare copper/binder composite filaments through mixing, extrusion and flowability evaluation.
Findings
The results showed that the suitable composite filaments applied for FFF should balance rigidity and plasticity. The combination of printing speed and heating temperature impacts on the surface quality significantly, and the major factor in determining the dimensional accuracy is layer thickness. Two-stage debinding procedure was beneficial for binder removal and sintering process. The higher sintering temperature results in less voids, sizes shrinkage and densified microstructure, which is attributed to the occurrence of sintering neck among the fused copper powders.
Originality/value
The self-prepared copper/binder composite filaments were successfully manufactured using the FFF process. This study provides unique approach and print guidance for fabricating complex structures of pure copper components.
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Jieren Guan, Qiuping Wang, Chao Chen and Jingyu Xiao
The purpose of this paper is to analyze and investigate heat accumulation caused by temperature changes and interface microstructure effected by element diffusion.
Abstract
Purpose
The purpose of this paper is to analyze and investigate heat accumulation caused by temperature changes and interface microstructure effected by element diffusion.
Design/methodology/approach
Al/Cu bimetallic structure is initially manufactured through laser powder bed fusion process. To minimize trial and error, finite element modeling is adopted to simulate temperature changes on the Al-based and Cu-based substrate.
Findings
The results show that forming pure copper on Al-based substrate can guarantee heat accumulation, providing enough energy for subsequent building. The instantaneous laser energy promotes increase of diffusion activation energy, resulting in the formation of transition zone derived from interdiffusion between Al and Cu atoms. The interface with a thickness of about 22 µm dominated by Kirkendall effect moves towards Al-rich side. The interface microstructure is mainly composed of a-Al, a-Cu and CuAl2 phase.
Originality/value
The bonding mechanism of Al/Cu interface is atom diffusion-induced chemical reaction. The theoretical basis provides guidance for structural design and production application.
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Qiuping Wang, Tiepeng Wang and Ke Zhang
Image edge detection is an essential issue in image processing and computer vision. The purpose of this paper is to provide a novel and effective algorithm for image edge…
Abstract
Purpose
Image edge detection is an essential issue in image processing and computer vision. The purpose of this paper is to provide a novel and effective algorithm for image edge detection.
Design/methodology/approach
Because GM (1,1) model is a typical model for tendency analysis, GM (1,1) model can be used for detecting edge. Prediction image data are close to the original image data by reason of the data being smooth in the non‐edge zone of image. The principle of edge detection by GM (1,1) model is that the predicted value at an edge point will be an overestimate or underestimate owing to the data changing drastically in the edge zone of the image. First, the edge image information is obtained by a preprocessed image subtracting from prediction image via GM (1,1). Second, median filter is used to eliminate isolated point noise in edge information images, and discrete wavelet transform is used to extract the image edge. Finally, this paper verifies the proposed algorithm by experiment.
Findings
Experimental results show that the proposed algorithm has advantages such as precisely locating, abundant weak edge, and better anti‐noise performance.
Practical implications
The algorithm proposed in the paper can precisely detect the information of edge image, and get a clear image detail.
Originality/value
Grey system theory developed vigorously lays the foundation for image processing. Wavelet analysis in image processing has its characteristics. This paper combines grey prediction model with discrete wavelet transform (DWT) successfully and obtains a novel and effective algorithm for image edge detection.
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Qiuping Wang, Subing Liu and Guoqiang Xiong
The aggregation of information from a group of decision experts for developing collective opinion is the important question in practice. The purpose of this paper is to provide a…
Abstract
Purpose
The aggregation of information from a group of decision experts for developing collective opinion is the important question in practice. The purpose of this paper is to provide a group decision-making method via ordered weighted aggregation (OWA) operator and grey incidence analysis.
Design/methodology/approach
In this study, OWA operator provides aggregation of attribute values to form an overall decision for each decision expert, and grey incidence model provides aggregation of decision experts’ evaluations to form overall score for each alternative. The example illustrates the procedure and practicability of the proposed model.
Findings
A new thought for multiple attribute group decision-making problems is given. The proposed method produces an overall desirability score for each alternative.
Practical implications
This is to obtain a more comprehensive and realistic solution to the given group decision-making problem. The proposed analysis method of group decision-making problems reveals vitality of grey systems theory.
Originality/value
This paper combines OWA operator and grey incidence analysis to obtain a novel and effective method for group decision making. It is suitable for group decision-making problems in which the attribute weights are completely unknown, expert weights are completely unknown.
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Xi Zhong, Qiuping Peng and Tian Wang
Based on social dilemma theory, the authors analyze the impact of leader reward omission on employee knowledge sharing and the boundary conditions in their relationship.
Abstract
Purpose
Based on social dilemma theory, the authors analyze the impact of leader reward omission on employee knowledge sharing and the boundary conditions in their relationship.
Design/methodology/approach
This study tested the theoretical hypotheses based on empirical data obtained from 264 employees using a two-wave survey method.
Findings
The results indicate that leader reward omission significantly negatively affects employee knowledge sharing. An employee's proactive personality weakens the negative relationship between them; the weakening effects of an employee's proactive personality would decrease along with the perceived increase in organizational unfairness.
Originality/value
This study provides the first insight that leader reward omission can inhibit employee knowledge-sharing behavior. In addition, this study shows that an individual proactive personality and perceived organizational unfairness moderate the relationship between leader reward omission and employee knowledge behavior. Thus, this study provides a more comprehensive understanding of whether and when leader reward omission affects employee knowledge sharing.
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Xi Zhong, He Wan and Qiuping Peng
The authors analyze the effects of controlling shareholders' stock pledging on firms' strategic change behavior, and investigate how the balance of power between shareholders and…
Abstract
Purpose
The authors analyze the effects of controlling shareholders' stock pledging on firms' strategic change behavior, and investigate how the balance of power between shareholders and analyst coverage moderates those effects.
Design/methodology/approach
Employing fixed effects models, the authors test hypotheses based on Chinese listed company data from 2011 to 2017.
Findings
Controlling shareholders' stock pledges has a negative effect on strategic change. As the balance of power among shareholders and/or analyst coverage increases, it mitigates the effect of controlling shareholder stock pledges on strategic change. In particular, the balance of power between shareholders and analyst coverage weakened the relationship between controlling shareholder stock pledges and strategic change. Lastly, after distinguishing family from nonfamily firms, the authors discovered that these findings only held for family firms.
Originality/value
This study makes important contributions to strategic change, stock pledge and family firm literature, and also provides guidance on firms' strategic change practices.
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Qiuping Peng, Xi Zhong, Huaikang Zhou and Shanshi Liu
This paper aims to investigate the moderating roles of negative attainment discrepancy and state ownership in the relationship between internationalization speed and firm…
Abstract
Purpose
This paper aims to investigate the moderating roles of negative attainment discrepancy and state ownership in the relationship between internationalization speed and firm innovation.
Design/methodology/approach
Panel fixed-effects regressions model was applied to test the influence of internationalization speed on firm innovation using data collected from Chinese listed companies between 2003 and 2017.
Findings
The internationalization speed can positively promote firm innovation. Moreover, negative attainment discrepancy enhances the effect of internationalization speed on firm innovation. The effect of negative attainment discrepancy on internationalization speed and firm innovation performance is more positive in state-owned firms than in non-state-owned firms.
Research limitations/implications
A suitable time of internationalization speed to affect firm innovation is obtained.
Practical implications
This paper suggests that decision-makers should set an appropriate aspiration to internationalize firms and increase firm innovation. Moreover, state-owned enterprises should pay attention to negative attainment discrepancies.
Originality/value
The study revealed the boundary conditions of negative attainment discrepancy and state ownership on the relationship between internationalization speed and firm innovation, contributing to the theoretical advancements in internationalization speed.
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Qiuping Peng, Xi Zhong, Shanshi Liu, Huaikang Zhou and Nannan Ke
In this paper, the moderating roles of leader reward omission and person–supervisor fit in the relationship between job autonomy and knowledge hiding are investigated.
Abstract
Purpose
In this paper, the moderating roles of leader reward omission and person–supervisor fit in the relationship between job autonomy and knowledge hiding are investigated.
Design/methodology/approach
Using a sample of 248 employees in a two-wave survey, we performed a hierarchical regression analysis to test the hypotheses.
Findings
The results revealed that employees with high job autonomy were less likely to engage in knowledge hiding. Moreover, when employees experienced leader reward omission, the negative relationship between job autonomy and knowledge hiding was weakened, and this interesting effect varied by person–supervisor fit.
Research limitations/implications
This study does not explore the mediating mechanism by which job autonomy affects employee knowledge hiding. Moreover, as this research was conducted in a Chinese context, the generalizability of our findings is unclear.
Practical implications
This research has fulfilled its practical aims by providing advice on knowledge-relevant job characteristic factors that can be used to stage interventions regarding the provision of autonomy in jobs, and by carefully considering how to create interdependence between jobs without pushing people to engage in knowledge-hiding behaviors. Furthermore, it is important for leaders to help employees identify work goals and directions and not engage in reward omission.
Originality/value
This study contributes to theoretical advancements in the field of knowledge hiding by revealing boundary conditions that mitigate or enhance the impact of job autonomy on knowledge hiding.