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Article
Publication date: 6 August 2018

Haixia Wang, Xiao Lu, Wei Cui, Zhiguo Zhang, Yuxia Li and Chunyang Sheng

Developing general closed-form solutions for six-degrees-of-freedom (DOF) serial robots is a significant challenge. This paper thus aims to present a general solution for…

Abstract

Purpose

Developing general closed-form solutions for six-degrees-of-freedom (DOF) serial robots is a significant challenge. This paper thus aims to present a general solution for six-DOF robots based on the product of exponentials model, which adapts to a class of robots satisfying the Pieper criterion with two parallel or intersecting axes among its first three axes.

Design/methodology/approach

The proposed solution can be represented as uniform expressions by using geometrical properties and a modified Paden–Kahan sub-problem, which mainly adopts the screw theory.

Findings

A simulation and experiments validated the correctness and effectiveness of the proposed method (general resolution for six-DOF robots based on the product of exponentials model).

Originality/value

The Rodrigues rotation formula is additionally used to turn the complex problem into a solvable trigonometric function and uniformly express six solutions using two formulas.

Book part
Publication date: 3 June 2021

Hakan Kalkavan, Serhat Yüksel and Hasan Dinçer

The aim of this chapter is to determine the relationship between labor productivity and economic development. In this context, the annual data of Turkey on a range of…

Abstract

The aim of this chapter is to determine the relationship between labor productivity and economic development. In this context, the annual data of Turkey on a range of 1970–2017 are included in the study period. On the other hand, these data are tested with the help of Toda Yamamoto causality analysis. Thus, it will be possible to determine whether there is a strong relationship between the two variables. According to the obtained results of the analysis, it is defined that there is a causal relationship from labor productivity to economic growth in Turkey. Based on these results, it can be said that labor productivity should rise in order to increase economic development in Turkey. For this purpose, educational programs in Turkey can be revised with the help of a detailed study. In this process, cooperation with companies to understand the needs in the market plays a key role. Additionally, regulations should also be prepared related to the salaries of the employees. If it can be possible to prevent employees from receiving wages below a certain amount by placing a minimum legal limit on salaries, it will be possible to increase the motivation of the employees. This situation has a positive and significant contribution to the labor productivity.

Details

Productivity Growth in the Manufacturing Sector
Type: Book
ISBN: 978-1-80071-094-8

Keywords

Abstract

Details

Airline Economics in Europe
Type: Book
ISBN: 978-1-78973-282-5

Article
Publication date: 9 August 2022

Wei Wei, Qi Cui and Yu Sheng

This paper aims to explore the future path of agricultural development in China toward 2060 under the dual carbon goals, so as to inform better policy choices for…

Abstract

Purpose

This paper aims to explore the future path of agricultural development in China toward 2060 under the dual carbon goals, so as to inform better policy choices for facilitating agricultural and rural transformation toward the goal of maintaining food security, sustainable income growth and low carbon emission.

Design/methodology/approach

This study employs a single-country, multi-sectoral computable general equilibrium model, CHINAGEM model and develops eight illustrative scenarios to simulate the impacts of attaining dual carbon goals on agricultural development in China. Additional two scenarios have also been designed to inform better policy making with the aim to offset the negative impact of the decarbonization schemes through facilitating agricultural technology progress.

Findings

Dual carbon goals are projected to impose substantial negative impact on agricultural productions and consumptions in China in the coming four decades. Under the assumption of business as usual, agricultural production will reduce by 0.49–8.94% along with the attainment of carbon neutrality goal by 2060, with the production of cereals and high-value being more severely damaged. To mitigate the adverse impact of the decarbonization schemes, it is believed that fastening technology progress in agriculture is one of the most efficient ways for maintaining domestic food security without harming the dual carbon goals. In particular, if agricultural productivity (particularly, for cereals and high-value products) can be increased by another 1% per year, the production losses caused by carbon emission mitigation will be fully offset. This implies that promoting technology progress is still the best way to facilitate agricultural development and rural transformation in future China.

Originality/value

The paper contributes to the literature in better informing the impact of dual carbon goals on China's agriculture and the effectiveness of technology progress in agriculture on buffering the adverse impact of the decarbonization schemes and promoting agricultural development.

Details

China Agricultural Economic Review, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1756-137X

Keywords

Abstract

Details

Crisis Communication in China
Type: Book
ISBN: 978-1-80117-983-6

Article
Publication date: 1 May 2019

Jinbo Wang, Naigang Cui and Changzhu Wei

This paper aims to develop a novel trajectory optimization algorithm which is capable of producing high accuracy optimal solution with superior computational efficiency…

Abstract

Purpose

This paper aims to develop a novel trajectory optimization algorithm which is capable of producing high accuracy optimal solution with superior computational efficiency for the hypersonic entry problem.

Design/methodology/approach

A two-stage trajectory optimization framework is constructed by combining a convex-optimization-based algorithm and the pseudospectral-nonlinear programming (NLP) method. With a warm-start strategy, the initial-guess-sensitive issue of the general NLP method is significantly alleviated, and an accurate optimal solution can be obtained rapidly. Specifically, a successive convexification algorithm is developed, and it serves as an initial trajectory generator in the first stage. This algorithm is initial-guess-insensitive and efficient. However, approximation error would be brought by the convexification procedure as the hypersonic entry problem is highly nonlinear. Then, the classic pseudospectral-NLP solver is adopted in the second stage to obtain an accurate solution. Provided with high-quality initial guesses, the NLP solver would converge efficiently.

Findings

Numerical experiments show that the overall computation time of the two-stage algorithm is much less than that of the single pseudospectral-NLP algorithm; meanwhile, the solution accuracy is satisfactory.

Practical implications

Due to its high computational efficiency and solution accuracy, the algorithm developed in this paper provides an option for rapid trajectory designing, and it has the potential to evolve into an online algorithm.

Originality/value

The paper provides a novel strategy for rapid hypersonic entry trajectory optimization applications.

Details

Aircraft Engineering and Aerospace Technology, vol. 91 no. 4
Type: Research Article
ISSN: 1748-8842

Keywords

Abstract

Details

Crisis Communication in China
Type: Book
ISBN: 978-1-80117-983-6

Abstract

Details

Crisis Communication in China
Type: Book
ISBN: 978-1-80117-983-6

Abstract

Details

Crisis Communication in China
Type: Book
ISBN: 978-1-80117-983-6

Abstract

Details

Crisis Communication in China
Type: Book
ISBN: 978-1-80117-983-6

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