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Browsing by Author "Ali, Syed A."

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    Blockchain Etextbook
    Ali, Syed A.; Gillies, Liam W.; Mulvaney, Elizabeth M. (Virginia Tech, 2021-12-08)
    The goal of the Blockchain Etextbook group was to develop new content related to Ethereum under the Blockchain section of the OpenDSA textbook. OpenDSA is designed to inform students and researchers within the field of computer science about key topics within the field. This team specifically covered the content related to Blockchain, a new area of study in computer science. The expected audience for this topic is students and researchers either currently working in, or who are studying the topics within, Blockchain. This textbook aims to provide a single place for referencing material related to the topic. Under the supervision of Dr. Cliff Shaffer at Virginia Tech, the team developed Blockchain content for the textbook. This included creating interactive exercises for the users to learn with and writing prose composed from researching resources about Blockchain and Ethereum. The original description of the project covered topics broadly within Blockchain but Dr. Shaffer narrowed his interest with the team down to Ethereum and topics related to that. The team wrote textbook content related to the concepts of Ethereum including proof of stake, hard forks, crypto hacking, Ethereum Virtual Machine (EVM), and Gas. Our deliverables were reStructured Text files and HTML exercises related to these topics. In addition, the report gives users a tutorial on how to use the chapters within the textbook as well as giving future developers details on how to modify and improve chapters within the books. The team learned some of the issues with writing a textbook on new material since there is often limited or conflicting information regarding the topics.
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    Climate change impacts on conventional and flash droughts in the Mekong River Basin
    Kang, Hyunwoo; Sridhar, Venkataramana; Ali, Syed A. (Elsevier, 2022-09-10)
    Recent drought events in the Mekong River Basin (MRB) have resulted in devastating environmental and economic losses, and climate change and human-induced alterations have exacerbated drought conditions. Using hydrologic models and multiple climate change scenarios, this study quantified the future climate change impacts on conventional and flash drought conditions in the MRB. The Soil and Water Assessment Tool (SWAT) and Variable Infiltration Capacity (VIC) models were applied to estimate long-term drought indices for conventional and flash drought conditions over historical and future periods (1966–2099), using two emission scenarios (RCP 4.5 and RCP8.5), and four climate models from the Coupled Model Intercomparison Project Phase 5 (CMIP5). For the conventional drought assessment, monthly scale drought indices were estimated, and pentad-scale (5 days) drought indices were computed for the flash drought evaluations. There were overall increases in droughts from the SWAT model for the conventional drought conditions and overall decreases from the VIC model. For the flash drought conditions, the SWAT-driven drought indices showed overall increases in drought occurrences (up to 165%). On the contrary, the VIC-driven drought indices presented decreases in drought occurrences (up to −44%). The conventional and flash drought evaluations differ between these models as they partition the water budget, specifically soil moisture differently. We conclude that the proposed framework, which includes hydrologic models, various emission scenarios, and projections, allows us to assess the various perspectives on drought conditions. Basin countries have differential impacts, so targeted future adaptation strategy is required.