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Leverage Sidechains to Reduce the Workload of Smart Contracts through Parallelization
Magne Saetran,Jungwon Seo,Sooyong Park 한국정보과학회 2021 Journal of Computing Science and Engineering Vol.15 No.3
Recently, blockchain has been evolving rapidly with new innovations, coins, and use cases every day. The platform is getting more congested due to the increase of interest and mainstream adoption, and because most of this activity is on the widely used Ethereum blockchain. This also further increases the costs of using the platform, as the gas prices become higher. Smart contracts are deployed on the Ethereum blockchain and the high usage of these smart contracts is one of the main reasons behind the congestion. We propose a new scheme using sidechains and a middleware to reduce the workload for certain smart contracts, which allows the execution of smart contract transactions in parallel through sidechains. In this way, the sidechains could be leveraged to decrease the congestion on the main blockchain and increase the rate of transactions per second. Furthermore, the sidechains could have their settings, like block time and block gas limit, adjusted to give more optimal results. We implemented a modified version of the ballot contract from the solidity documentation, and our results demonstrated that through the use of two sidechains, the transactions processed per second could be increased from 1.8× to 13.0×, depending on the sidechains settings.
Design and tests of 500kW RF windows for the ITER LHCD system
Hillairet, J.,Kim, J.,Faure, N.,Achard, J.,Bae, Y.S.,Bernard, J.M.,Delpech, L.,Goniche, M.,Larroque, S.,Magne, R.,Marfisi, L.,Park, S.,Poli, S.,Dechambre, N.,Vulliez, K. Elsevier 2015 Fusion engineering and design Vol.94 No.-
<P><B>Abstract</B></P> <P>In the frame of a R&D effort conducted by CEA towards the design and the qualification of a 5GHz LHCD system for the ITER tokamak, two 5GHz 500kW/5s windows have been designed, manufactured and tested at high power in collaboration with the National Fusion Research Institute (NFRI). The window design rely on a symmetrical pill-box concept with a cylindrical beryllium oxide ceramic brazed on an actively water cooled copper skirt. The ceramic RF properties have been measured on a test sample to get realistic values for guiding the design. Low power measurements of the manufactured windows show return losses below −32dB and insertion losses between −0.01dB and −0.05dB, with an optimum frequency shifted toward lower frequencies. High power tests conducted at NFRI show unexpected total power loss for both windows. The ceramic temperature during RF pulses has been found to reach unexpected high temperature, preventing these windows to be used under CW conditions. A post-mortem RF analysis of samples taken from one window shows that the dielectric properties of the ceramic were not the ones measured on the manufacturer sample, which partly explain the differences with the reference modelling.</P>
Christian Linde,Kasper G. Andersson,Sigurður M. Magnússon,Finn Physant 한국원자력학회 2019 Nuclear Engineering and Technology Vol.51 No.3
A comprehensive study of photon interaction features has been made for some alloys containing Pd andAg content to evaluate its possible use as alternative gamma radiations shielding material. The massattenuation coefficient (m/r) of the present alloys was measured at various photon energies between 81keV e 1333 keV utilizing HPGe detector. The measured m/r values were compared to those of theoreticaland computational (MCNPX code) results. The results exhibited that the m/r values of the studied alloysare in same line with results of WinXCOM software and MCNPX code results at all energies. Moreover,Pd75/Ag25 alloy sample has the maximum radiation protection efficiency (about 53% at 81 keV) andlowest half value layer, which shows that Pd75/Ag25 has superior gamma radiation shielding performanceamong the compared other alloys.