Mahmoud Taban and Alireza Basohbat Novinzadeh
One of the challenges encountered in the design of guided projectiles is their prohibitive cost. To diminish it, an appropriate avenue many researchers have explored is the use of…
Abstract
Purpose
One of the challenges encountered in the design of guided projectiles is their prohibitive cost. To diminish it, an appropriate avenue many researchers have explored is the use of the non-actuator method for guiding the projectile to the target. In this method, biologically inspired by the flying concept of the single-winged seed, for instance, that of maple and ash trees, the projectile undergoes a helical motion to scan the region and meet the target in the descent phase. Indeed, the projectile is a decelerator device based on the autorotation flight while it attempts to resemble the seed’s motion using two wings of different spans. There exists a wealth of studies on the stability of the decelerators (e.g. the mono-wing, samara and pararotor), but all of them have assumed the body (exclusive of the wing) to be symmetric and paid no particular attention to the scanning quality of the region. In practice, however, the non-actuator-guided projectiles are asymmetric owing to the presence of detection sensors. This paper aims to present an analytical solution for stability analysis of asymmetric decelerators and apprise the effects of design parameters to improve the scanning quality.
Design/methodology/approach
The approach of this study is to develop a theoretical model consisting of Euler equations and apply a set of non-dimensionalized equations to reduce the number of involved parameters. The obtained governing equations are readily applicable to other decelerator devices, such as the mono-wing, samara and pararotor.
Findings
The results show that the stability of the body can be preserved under certain conditions. Moreover, pertinent conclusions are outlined on the sensitivity of flight behavior to the variation of design parameters.
Originality/value
The analytical solution and sensitivity analysis presented here can efficiently reduce the design cost of the asymmetric decelerator.
Details
Keywords
Ernest Sogah, John Kwaku Mensah Mawutor, Isaac Ofoeda and Freeman Christian Gborse
The impact of government expenditure on economic performance has been a topic of discussion at both the sectoral and aggregate national levels. Despite its theoretical importance…
Abstract
Purpose
The impact of government expenditure on economic performance has been a topic of discussion at both the sectoral and aggregate national levels. Despite its theoretical importance, evidence from literature indicates that this relationship has not been universally accepted across different countries and sectors. Given the significance of agriculture in African economies, particularly in Ghana, and the role of government in this sector, this study examines the impact of government expenditure on agricultural productivity in Ghana from 2000Q1 to 2022Q4.
Design/methodology/approach
Specification of the model was done based on the Autoregressive Distributed Lag (ARDL) cointegration bound test approach.
Findings
The results revealed that the studied variables cointegrated in the long run. Government expenditure was found to induce agriculture production both for the long run and short run within the period of the study, implying that government expenditure matters in inducing agriculture productivity in Ghana.
Originality/value
The study employed the ARDL methodology to investigate government expenditure and agriculture production contagion in Ghana, which has been specifically overlooked by previous studies. It is suggested that the Government of Ghana as well as others in similar environment should increase investment into the agriculture to boost the productivity of the sector.