Estimating Volatility in Prices of Pulses in India: An Application of Garch Model

Although, India is the largest pulse producing country in the world, the production of these crops in the country has shown sluggish growth over the years. Low growth rate coupled with high fluctuations in production of pulses is mainly responsible for poor performance of pulse sector. It also leads to high price variability. Variability in the prices of pulses is a major concern for decision makers. This study was conducted to estimate the volatility in the prices of major pulses (chickpea, pigeonpea, blackgram, greengram and lentil) in India using GARCH model. Results have shown that the volatility in the current period depends on volatility in the preceding period in case of pulses as evident from the significant ARCH term for all the crops. Further, the sum of α and β coefficients has been found more than one for all the pulse crops except pigeonpea in period I thus indicating an explosive price series with a tendency to meander away from mean value. The volatility in the price series of pigeonpea has been found more persistent and explosive in recent period. So, there is a need for regular monitoring of prices and appropriate interventions by the government, when necessary, to make the development of pulse sector more sustainable

Design of a modified MIMO antenna based on tweaked spherical fractal geometry for 5G New Radio (NR) band N258 (24.25–27.25 GHz) applications

This article describes a fractal-based MIMO antenna for 5G mm-wave mobile applications with micro-strip feeding. The proposed structure is a fractal-based spherical configuration that incorporates spherical slots of different iterations on the patch, as well as rectangular slots on the ground plane. These additions are meant to reduce patch isolation. The two-element MIMO antenna has closely spaced antenna elements that resonate at multiple frequencies, 9.5 GHz, 11.1 GHz, 13.4 GHz, 15.8 GHz, 21.1 GHz, and 26.6 GHz, in the frequency range of 8 to 28 GHz. The antenna’s broadest operational frequency range spans from 17.7 GHz to 28 GHz, encompassing a bandwidth of 10,300 MHz. Consequently, it is well-suited for utilization within the millimeter wave (mm wave) application, specifically for the 5G new radio frequency band n258, and partially covers some other bands X (8.9–9.9 GHz, 10.4–11.4 GHz), and Ku (13.1–13.7 GHz, 15.4–16.2 GHz). All the resonating bands have isolation levels below the acceptable range of (|S12| > −16 dB). The proposed antenna utilizes a FR4 material with dimension of 28.22 mm × 44 mm. An investigation is conducted to analyze the effectiveness of parameters of the antenna, including radiation pattern, surface current distributions and S parameters. Furthermore, an examination and assessment are conducted on the efficacy of the diversity system inside the multiple input multiple output (MIMO) framework. This evaluation encompasses the analysis of key performance metrics such as the envelope correlation coefficient (ECC), diversity gain (DG), and mean effective gain (MEG). All antenna characteristics are determined to be within a suitable range for this suggested MIMO arrangement. The antenna design underwent experimental validation and the simulated outcomes were subsequently verified