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Review of Antennas for Railway Communications
Arya Ashwini K.,한소율,김상혁 한국전자파학회 2023 Journal of Electromagnetic Engineering and Science Vol.23 No.2
This paper presents a review of the state-of-the-art antennas for the railway communications. There are various aspects that one should consider when designing an antenna, such as antenna size and directivity. While size constraints on railway antennas are not as critical as for mobile consumer counterparts, a radome structure is required to cover the antenna to minimize the aerodynamic resistance antenna. This paper reviews aerodynamic simulations to account for the drag coefficient of the antenna. In a low-frequency band (<5 GHz), railway antennas used to be omnidirectional in the horizontal plane. As the communication scheme advances toward 5G technology, high directivity is required for the railway antenna to compensate for the high path loss at high-frequency bands, i.e., 28-GHz band. We review recent studies of railway antennas over various frequency bands, such as LTE-R, LTE, and the lower and upper 5G bands. To accommodate multiple frequency bands with a single antenna, along with the aerodynamic radome cover, design techniques allowing multiple frequency bands are reviewed in this paper.
Global Energy, Environment and Transportation Sector : Issues, Challenges and Future Prospects
Arya Kumar 한국유통과학회 2017 KODISA ICBE (International Conference on Business Vol.2017 No.-
Human existence and development have long been mainly dependent on use of energy - for survival growth and development. The prosperity of mankind essentially revolves around their ability to capture, gather, harness and utilize energy for productive purposes in a productive manner. Transportation sector alone consume more than 25% of global energy demand. It is mainly reliant (95%) upon petroleum products with the exception of railways using electrical power. It is estimated that the transport sector is responsible for about 25 percent of emissions of the gases contributing to global warming in industrialized countries, and about one-half this amount in developing countries. A transportation system that needs to be affordable, safe, efficient and environment friendly is a fundamental constituent of sustainable development. Bio-fuels, ethanol, and bio-diesel hold great promise towards a safer and healthy environment by replacing imported oil by indigenously produced fuels. This paper attempts to focus on technological priorities that need to be well defined; especially regarding elimination of lead from gasoline and elimination or cleaning up of high-mileage, heavily polluting vehicles along with appropriate incentive systems to overcome the problem of environmental deterioration.
Selective Reduction of Nitro Compounds Using CeY Zeolite Under Microwaves
Arya, Kapil,Dandia, Anshu Korean Chemical Society 2010 대한화학회지 Vol.54 No.1
포화 그리고 방향족 니트로화합물은 monomode reactor로 CeY zeolite와 formic acid를 사용하여 반응시키면 아민 치환체를 좋은 수율로 선택적으로 환원된다. 이 반응은 몇개의 민감한 작용기를 가진 화합물에 적합하다. 회수한 촉매를 20회 이상 사용 후에도 촉매의 활성을 계속 유지하였다. Aliphatic and aromatic nitro compounds were selectively reduced to their corresponding amino derivatives in good yields using formic acid and CeY zeolite under monomode reactor. This system is found to be compatible with several sensitive functionalities. Beside the recycling result showed it had a long catalyst lifetime and could maintain activity even after being used for 20 cycles.
Planar ultra-wideband printed wide-slot antenna using fork-like tuning stub
Arya, Ashwini K.,Aziz, Rao Shahid,Seong-Ook Park IET 2015 Electronics letters Vol.51 No.7
<P>A printed wide-slot antenna with a centred rectangular parasitic patch, fed by a fork-like tuning stub with rectangular parasitic elements adjacent to the main feed line is proposed and discussed. The proposed wide-slot antenna eliminates the need of rotation of the slot and parasitic patches both in the ground plane for the improvement in impedance bandwidth. The experimental results indicate that the presented antenna has a bandwidth (-10 dB) of more than 148% ranging from 2 to 13.5 GHz. The total size of the proposed antenna configuration is 44.3 × 44.3 × 0.508 mm<SUP>3</SUP>.</P>
ARYA SUDHANSHU,Chung Yeon Ho 한국통신학회 2023 ICT Express Vol.9 No.6
By leveraging the characteristics of both quantum encoding and classical data channel, we present a unique and novel multiuser optical communication system that utilizes fascinating properties of the structured light for information transmission. Specifically, we propose an indoor orbital angular momentum (OAM) multiuser multiple-input multiple-output (MIMO) optical communication system, where the quantum encoding is performed and the multiuser transmission is then analyzed from the context of the classical data channel. In the proposed system, as the OAM beam propagates, its angular spread is analyzed. In addition, we show that the variance of the beam divergence increases with the increasing OAM index mode on the basis of the derived MIMO channel impulse response for OAM carrying Laguerre–Gaussian beams. Comparative studies reveal that the proposed system significantly outperforms the conventional non-orthogonal multiple access (NOMA) applied with MIMO.
Vanillin: a review on the therapeutic prospects of a popular flavouring molecule
Arya Sagar S.,Rookes James E.,Cahill David M.,Lenka Sangram K. 경희대학교 융합한의과학연구소 2021 Oriental Pharmacy and Experimental Medicine Vol.21 No.3
Vanilla is the world’s most popular flavour extracted from the pods of Vanilla planifolia orchid. It is a mixture of ~ 200 compounds but its characteristic flavour and fragrance primarily come from vanillin. While the importance of its wide usage in flavour and fragrance is well established, there have been limited investigations to evaluate its bioactive potential. However, a few studies have reported a promising array of bioactivities that could be exploited for multiple therapeutic applications. Recently, bioactive properties of vanillin, such as neuroprotection, anticarcinogenic, and antioxidant are gaining attention. Besides this, vanillin and its synthetic analogues are found to regulate gene expression and exhibit biological activities. Therefore, here we summarize the potential bioactivates of vanillin and its derivative with an aim to change the perspective from being a popular flavour to a new age therapeutics molecule.
Dual Polarized Dual Antennas for 1.7–2.1 GHz LTE Base Stations
Arya, Ashwini K.,Nguyen Viet Anh,Aziz, Rao S.,Byeong Yong Park,Seong-Ook Park IEEE 2015 IEEE antennas and wireless propagation letters Vol.14 No.-
<P>A novel antenna with both horizontal and vertical polarizations is proposed for 1.7-2.1 GHz LTE band small cell base stations. Horizontal polarization is achieved by using the Vivaldi antennas at the main PCB board in azimuth plane, whereas the vertical polarization is obtained using the rectangular monopole with curved corners in proximity of the horizontal elements. A prototype antenna associated with 8-elements (four horizontal and four vertical) is fabricated on the FR4 substrate with the thickness of 0.2 cm and 0.12 cm for Vivaldi and monopole antennas, respectively. Experimental results have validated the design procedure of the antenna with a volume of 14 x 14 x 4.5 cm(3) and indicated the realization of the requirements for the small cell base station applications.</P>
ARYA SUDHANSHU,정연호,정완영,김종진,김남호 한국통신학회 2021 ICT Express Vol.7 No.3
In this paper, we address the problem of joint transmit beamforming and power control for a multiuser multiple-input single-output (MISO) indoor optical downlink channel. We adopt a shot-noise limited Poisson channel with transmitting signals subject to average and peak transmits power constraints. To minimize the total transmit power, we formulate an optimal downlink beamforming problem using convex optimization method via second-order cone programming techniques. In our approach, the total transmit power is optimized subject to the signal-to-interference-plus-noise ratio (SINR). The results verify performance improvements of the proposed technique as compared to conventional multiuser MISO indoor optical systems.