An Evaluation of Security in Blockchain-based Sharing of Student Records in Higher Education

Blockchain has recently taken off as a disruptive technology, from its initial use in cryptocurrencies to wider applications in areas such as property registration and insurance due to its characteristic as a distributed ledger which can remove the need for a trusted third party to facilitate transactions. This spread of the technology to new application areas has been driven by the development of smart contracts – blockchain-based protocols which can automatically enforce a contract by executing code based on the logic expressed in the contract. One exciting area for blockchain is higher education. Students in higher education are ever more mobile, and in an ever more agile world, the friction and delays caused by multiple levels of administration in higher education can cause many anxieties and hardships for students as well as potential employers who need to examine and evaluate student credentials. Distance learning as a primary platform for higher education promises to open up higher education to a wider range of learners than ever before. Blockchain-based storage of academic credentials is being widely studied due to the advantages it can bring. As with any network-based system, blockchain comes with a number of security and privacy concerns. Blockchain needs to meet several security-related requirements to be widely accepted: decentralization; confidentiality; integrity; transparency; and immutability. Researchers have been busy devising schemes to ensure that such requirements can be met in blockchain-based systems. Several types of blockchain-specific attacks have been identified: 51% attacks; malicious contracts; spam attacks; mining pools; targeted DDoS attacks; and others. Real-world attacks on blockchain-based systems have been seen on cryptocurrency sites. In this paper, we will evaluate the specific privacy and security concerns for blockchain-based systems used for academic credentials as well as suggested solutions. We also examine the issues for academic credentials which are stored “off-chain” in such systems (as is often the case). In this case, a Distributed File System (DFS) implemented with a peer-to-peer (P2P) architecture is often the choice for the storage of the academic credentials since it matches the decentralized nature of blockchain. Blockchain then contributes much to the usefulness of such a DFS, making it in turn a good match for a P2P DFS such as IPFS

Case Study of Ground-Based Glaciogenic Seeding of Clouds over the Pyeongchang Region

Ground-based glaciogenic seeding experiments were conducted at the Daegwallyeong Cloud Physics Observation Site (CPOS) from 2012 to 2015 for the target area Yongpyeong, which lies 9 km away. The preseeding (NOSEED) and seeding (SEED) periods were defined based on the simulation results of AgI concentration (>10 L−1) in the Weather Research and Forecast (WRF) model with the modified Morrison scheme in microphysics. It was difficult to determine whether snow enhancement via seeding occurred over the entire target area due to uncertainties associated with limitations such as observations and numerical model based on only two points (seeding and target sites). However, in three of four cases, the vertical reflectivity from micro rain radar, total concentration, and average size of snow particles observed at PARSIVEL and precipitation increased in the seeding effect time. In two of four cases, the simulated increased precipitation during the seeding effect time was also observed. In one case that did not show changes after seeding, it is analyzed that a sufficient cloud depth was not supplied to the seeding region due to the blocking effect of the Taebaek Mountains

Progressive and Prospective Technology for Cloud Seeding Experiment by Unmanned Aerial Vehicle and Atmospheric Research Aircraft in Korea

This study applies a novel cloud seeding method using an unmanned aerial vehicle (UAV) and a research aircraft in Korea. For this experiment, the UAV sprayed a cloud seeding material (calcium chloride), and the aircraft monitored the clouds in the southern part of the Korean Peninsula on April 25, 2019. Cloud observation equipment in the aircraft indicated an increase in the number concentration and average particle size of large cloud particles after the seeding. Weather radar reflectivity increased by approximately 10 dBZ above the experimental area due to the development of clouds and precipitation systems. Rain was observed after seeding, and 0.5 mm was recorded, including natural and mixed precipitation from the cloud seeding. In addition, it showed that the rapid increase in the number of raindrops and vertical reflectivity was approximately 10 dBZ. Therefore, these results showed the possibility of cloud seeding using UAVs and atmospheric research aircraft. The effects of cloud seeding are indicated through the increased number concentration and size of cloud particles, radar reflectivity, and ground-based precipitation detection