Fangli Mou and Dan Wu
In recent years, owing to the rapidly increasing labor costs, the demand for robots in daily services and industrial operations has been increased significantly. For further…
Abstract
Purpose
In recent years, owing to the rapidly increasing labor costs, the demand for robots in daily services and industrial operations has been increased significantly. For further applications and human–robot interaction in an unstructured open environment, fast and accurate tracking and strong disturbance rejection ability are required. However, utilizing a conventional controller can make it difficult for the robot to meet these demands, and when a robot is required to perform at a high-speed and large range of motion, conventional controllers may not perform effectively or even lead to the instability.
Design/methodology/approach
The main idea is to develop the control law by combining the SMC feedback with the ADRC control architecture to improve the robustness and control quality of a conventional SMC controller. The problem is formulated and solved in the framework of ADRC. For better estimation and control performance, a generalized proportional integral observer (GPIO) technique is employed to estimate and compensate for unmodeled dynamics and other unknown time-varying disturbances. And benefiting from the usage of GPIO, a new SMC law can be designed by synthesizing the estimation and its history.
Findings
The employed methodology introduced a significant improvement in handling the uncertainties of the system parameters without compromising the nominal system control quality and intuitiveness of the conventional ADRC design. First, the proposed method combines the advantages of the ADRC and SMC method, which achieved the best tracking performance among these controllers. Second, the proposed controller is sufficiently robust to various disturbances and results in smaller tracking errors. Third, the proposed control method is insensitive to control parameters which indicates a good application potential.
Originality/value
High-performance robot tracking control is the basis for further robot applications in open environments and human–robot interfaces, which require high tracking accuracy and strong disturbance rejection. However, both the varied dynamics of the system and rapidly changing nonlinear coupling characteristic significantly increase the control difficulty. The proposed method gives a new replacement of PID controller in robot systems, which does not require an accurate dynamic system model, is insensitive to control parameters and can perform promisingly for response rapidity and steady-state accuracy, as well as in the presence of strong unknown disturbances.
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Shuifa Ke, Dan Qiao and Zhangchun Chen
The purpose of this paper is to analyze the influence of different factors on forestry production, with an aim to explore the degree of connection between forestry economic growth…
Abstract
Purpose
The purpose of this paper is to analyze the influence of different factors on forestry production, with an aim to explore the degree of connection between forestry economic growth and influencing factors such as forestry investment, labor input, afforestation area, scientific and technologies progress, and the reform of property-rights regimes.
Design/methodology/approach
According to the data of China Forestry Statistical Yearbook from 1978 to 2017, this paper uses the grey correlation analysis to observe and analyze the factors influencing China’s forestry economics growth.
Findings
The results show that capital investment demonstrates the largest impact on the forestry output value, followed by property system, afforestation area, labor input and technologies progress. The correlation coefficients of the above factors are 0.874451654,0.85827468,0.835138412,0.832985604 and 0.825747493. This means that forestry capital investment plays a major role in contributing to forest economic growth; forest property system also plays a positive role in the growth of forestry economy.
Originality/value
This paper uses continuous data collected during 1978‒2017, which are quite extensive as compared to data used in the existing research, considering the influencing factors are comprehensive, especially the impact of property right system reform on forestry economic growth.
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Dan Qiao, Shuifa Ke, Xiaoxiao Zhang and Qiya Feng
The paper aims to explore the impact of marketization on forestry economic growth. Firstly, the development process of forestry marketization was summarized. Secondly, from the…
Abstract
Purpose
The paper aims to explore the impact of marketization on forestry economic growth. Firstly, the development process of forestry marketization was summarized. Secondly, from the three dimensions of forestry production factor marketization, production marketization and product marketization, the framework of marketization is constructed by the authors.
Design/methodology/approach
Based on the yearbook data from 1978 to 2016, the relationship between forestry marketization and forestry growth was demonstrated through multiple regression and Granger test in this paper.
Findings
The results showed that forestry marketization was one of the important driving factors that impacted on China's forestry economic growth. Since the reform and opening up, China's forestry marketization degree has been constantly strengthened, but there is still room for improvement. China has provided an important model as forestry marketization reform and development sample for the world.
Social implications
Many useful references and inspirations have been provided from China such as gradually promoting market-oriented reforms; paying attention to the important role of reform and opening up in the construction of market mechanism; dynamic coordination of market and government relations; developing and connecting the relationship between domestic and international market; and coordinating the development of forestry state-owned economy, private economy and mixed ownership economy.
Originality/value
This paper creates a measure index of forestry marketization from three dimensions of forestry production factor marketization, production marketization and product marketization.
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Tingwei Gao, Yueting Chai and Yi Liu
The main purpose of this paper is to conduct an in-depth theoretical review and analysis for the fields of knowledge management (KM) and investigate the future research trend…
Abstract
Purpose
The main purpose of this paper is to conduct an in-depth theoretical review and analysis for the fields of knowledge management (KM) and investigate the future research trend about KM.
Design/methodology/approach
At first, few theoretical basis about KM which include definitions and stages about KM have been summarized and analyzed. Then a comprehensive review about the major approaches for designing the KM system from different perspectives including knowledge representation and organization, knowledge sharing and performance measure for KM has been conducted.
Findings
The contributions of this paper will be useful for both academics and practitioners for the study of KM.
Originality/value
For this research, the focus is on conducting an in-depth theoretical review and analysis of KM.