Iraqi Journal for Computer Science and Mathematics

The year 2020 has shown the quick spread and devastating effect of Coronavirus (COVID-19) on
the world economy, health, and human life. Combating the COVID-19 pandemic is crucial. Blockchain technology
can assist in the fight against the COVID-19 pandemic by assuring safe and reliable medical supplies, accurate
identification of virus hot spots, and establishing data provenance to verify genuine personal protective equipment that
is decentralized, reliable, traceable, and transparent. A major proportion of current healthcare systems are centralized
and are short on privacy and information necessary for the detection of fraud connected to the certification by the
COVID-19 vaccine. The quick vaccination rollout and the deployment of a global vaccination campaign are crucial
and dependent on the availability of transparent and operational distribution chains, which may be audited by all
the necessary parties. Blockchain technology might also be used to assure transparent monitoring, storage, and
distribution of COVID19 vaccinations. Smart contracts are built for monitoring and tracking the proper circumstances
of vaccine distribution in comparison to safe handling of vaccine producers, informing all network peers. This study
aims to investigate the effectiveness of block chain and smart contracts in the health care system. The article presents a
model of the decentralized infrastructure of the health care system. The blockchain and intelligent contract technology
provided has shown promising results. The proposed solution is economically feasible and ensures data integrity,
security, transparency, and traceability. Future work aims to expand the functionalities of smart contracts and the
blockchain technology.

In most optimal VM placement algorithms, the first step to determine the proper time horizon, Tfor the prediction of the expected maximum future load, L. However, T is dependent on the proper knowledge of therequired time for servers to switch from their initial SLEEP/ACTIVE state to the next desired state. The activitiesimplemented by this policy are (a) to relocate the VM from an encumbered server, a server that operates in anundesirably high regime with applications forecasted to rise their burdens to compute in the subsequent reallocationcycles; (b) to conduct VM migration from servers that operate within the undesirable regime to shift the server toa SLEEP mode; (c) putting an idle server to SLEEP mode and rebooting the servers from the SLEEP mode at highcluster loads. A novel mechanism for forwarding arriving client desires to the utmost suitable server is implemented;thus, in the complete system, balancing the requested load is possible