Artificial Intelligence for Resilience in Smart Grid Operations

Today, the electric power grid is transforming into a highly interconnected network of advanced technologies, equipment, and controls to enable a smarter grid. The growing complexity of smart grid requires resilient operation and control. Power system resilience is defined as the ability to harden the system against and quickly recover from high-impact, low-frequency events. The introduction of two-way flows of information and electricity in the smart grid raises concerns of cyber-physical attacks. Proliferated penetration of renewable energy sources such as solar photovoltaic (PV) and wind power introduce challenges due to the high variability and uncertainty in generation. Unintentional disruptions and power system component outages have become a threat to real-time power system operations. Recent extreme weather events and natural disasters such as hurricanes, storms, and wildfires demonstrate the importance of resilience in the power system. It is essential to find solutions to overcome these challenges in maintaining resilience in smart grid. In this dissertation, artificial intelligence (AI) based approaches have been developed to enhance resilience in smart grid. Methods for optimal automatic generation control (AGC) have been developed for multi-area multi-machine power systems. Reliable AI models have been developed for predicting solar irradiance, PV power generation, and power system frequencies. The proposed short-horizon AI prediction models ranging from few seconds to a minute plus, outperform the state-of-art persistence models. The AI prediction models have been applied to provide situational intelligence for power system operations. An enhanced tie-line bias control in a multi-area power system for variable and uncertain environments has been developed with predicted PV power and bus frequencies. A distributed and parallel security-constrained optimal power flow (SCOPF) algorithm has been developed to overcome the challenges in solving SCOPF problem for large power networks. The methods have been developed and tested on an experimental laboratory platform consisting of real-time digital simulators, hardware/software phasor measurement units, and a real-time weather station

Valuing Ecosystem Services from Restoring Ancient Irrigation Systems: An application comparing labor vs. monetary payments for choice experiments

The use of stated preference methods in developing countries is growing with the increasing concern about the environment as economies develop. At the same time using monetary payment vehicles and estimating a Willingnessto Pay (WTP) can be problematic in rural or low incomes areas in developing countries. Many respondents in these areas regularly engage in barter and paying with labor and do not use monetary payments for all transactions. This distinction from urban areas with a monetary economy and with most settings in developed countries can impact results from valuation studies as the WTP elicited from rural and low-income areas is likely to be low even though respondents may have a high value and be willing to pay through other means. In response to these concerns, a growing number of stated preference studies explore using both monetary and non-monetary payment options. We contribute to this literature by exploring how the use of monetary vs labor payment options can impact values elicited from choice experiment studies conducted in rural developing country settings. Our application is a choice experiment survey to value restoring an ancient irrigation system know as cascading tank systems in Sri Lankan. The cascading tank systems are designed to complement the surrounding landscape and has parallels to the Japanese land use system of Satoyama. In Sri Lanka, these irrigations systems were created over 1500-2000 years ago but are still functioning today and provide irrigation for nearly 40% of the total irrigable area of the country. At the same time these ancient systems are degrading and there a large number of efforts to restore these systems which the FAO recently identified as a Globally Important Agricultural Heritage Systems (GIAHS). We conduct a choice experiment to understand the WTP/willingness-to-contribute of rural households to restore these irrigation systems. We also contribute to the literature on the applications of choice experiments in developing country settings by comparing data gathering methods, specifically individual surveys vs group information session. We find that in the individual survey settings respondents are more willing to contribute labor (compared to an equivalent monetary payment). Based on the early results we find that there is no difference between the group and individual survey settings when the survey is presented as a monetary payment but for the labor payment treatment, the group setting results in a positive payment coefficient for the labor payment attribute (i.e. respondents are willing to contribute labor when the survey is conducted in a group setting). We are currently exploring the heterogeneity of these results across respondents and plan to include these new results in the presentation as well

Essays on the political economy of conflict

In early anarchic states of society, the distribution of resources was determined primarily by private capacity for violence. Increasingly, sophisticated political systems have attempted to consolidate this capacity in the hands of the state as an enforcer of rights to resources. Nevertheless, even in modern democracies, private resources continue to be used in attempts to control the state and influence distribution. This thesis explores some of the tensions between violence and democratic process in several settings: resource contests, elections and intra-state conflicts. A participatory state is a pre-commitment by rational individuals to avoid conflict by mutually contributing towards an impartial peacekeeper. In the first essay (Chapter 2), I use a laboratory experiment to test the propensity to make costly investments in an institution for mutual conflict-avoidance in a rent-seeking game. I find that this specific institution induces agents to reduce conflict effort compared to when the institution is unavailable. This result is robust to egalitarian and unequal distributions of endowments. In the second and third essays (Chapters 3 and 4), I empirically investigate the roles of pre-election and post-election violence in the political economy of African national-level elections. Using an instrument variable regression model, I find a positive partial effect of pre-election violence on voter support for incumbent. I also find that the incidence of post-election violence drops when incumbent is re-elected. The partial effect of the incumbent’s margin of victory on post-election violence is negative in linear and Poisson regressions, and the local average effect of the incumbent’s victory is negative in a regression-discontinuity setting. In the fourth essay (Chapter 5), I focus on the salience of ethnic fractionalisation and polarisation in explaining the severity of intra-state conflicts. Three levels of conflict severity are modelled using a generalised ordered response model, simultaneously estimating parameters for each threshold of conflict severity. I find that polarisation, fractionalisation, and income inequality are respectively associated with minor, moderate and major conflict. In effect, the salience of polarisation and fractionalisation is found to be dependent on the severity of conflict

Exploring the impact of online politics on political agents and political strategies in the Sri Lankan Tamil diaspora

The thesis explores the role and impact of the internet on Sri Lankan Tamil diaspora political activism, focusing on both the experiences of political activists and on an analysis of web content related to diaspora activism. The central argument of the thesis is based around the relationship between political agents and cyberspace. The thesis argues that the political strategies and tactics adopted in the Tamil diasporan political sphere have changed with an increased dependence on the internet changing with it the politics and lives of individual activists. Cyberspace is presented as a site of power struggle with power as both an objective and source in micro-political struggles. The thesis also highlights the double sense of space attributed to cyberspace, both as a space facilitating political activism and as a qualitatively new space for politics. It traces the manifestation of violence in cyberspace based on its extensive reach and the collateral damage it can cause in political conflicts. Also the thesis argues that these intense web engagements for domination and resistance within the diaspora communities cause the emergence of new political priorities in Tamil diaspora politics. These do not parallel political developments in the conflict back in Sri Lanka. The thesis is based on research conducted from 2005 to 2008 during heightened rivalries between supporters of the LTTE (Liberation Tigers of Tamil Eelam) and dissident Tamil diaspora political activists which involved the extensive use of cyberspace for political purposes. The empirical research consisted of an integrated framework of online and offline research. The offline research was based on eight months of fieldwork in London including interviews with Tamil diaspora political activists across the spectrum from pro-LTTE to anti-LTTE dissidents. The online research was based on the technique of Web Sphere Analysis, which enables a framing of web content into a coherent unit of analysis

Ontology specific visual canvas generation to facilitate sense-making-an algorithmic approach

Ontologies are domain-specific conceptualizations that are both human and machine-readable. Due to this remarkable attribute of ontologies, its applications are not limited to computing domains. Banking, medicine, agriculture, and law are a few of the non-computing domains, where ontologies are being used very effectively. When creating ontologies for non-computing domains, involvement of the non-computing domain specialists like bankers, lawyers, farmers become very vital. Hence, they are not semantic specialists, particularly designed visualization assistance is required for the ontology schema verifications and sense-making. Existing visualization methods are not fine-tuned for non-technical domain specialists and there are lots of complexities. In this research, a novel algorithm capable of generating domain specialists’ friendlier visualization canvas has been explored. This proposed algorithm and the visualization canvas has been tested for three different domains and overall success of 85% has been yielded

Political history of the Kingdom of Kotte (c. A.D. 1400-1521).

This thesis is offered as a contribution to the study of the medieval history of Ceylon. In this study an attempt is made to examine the historical developments mainly political in the principal kingdom of Ceylon in the fifteenth century and in the early part of the sixteenth century. The first chapter surveys the original sources which could be utilized for the study of this period. Major part of this chapter is devoted to make an assessment of the historical value of the Rajavaliya. The second chapter deals mainly with the origin of the kingdom of Kotte. The activities of the Alakesvaras and the building of the fortress of Kotte are studied in it. In the same chapter the Chinese invasion and its repurcussions on the development of the kindom are studied. The third and fourth chapters are on the reign of Parakramabahu VI. While an attempt has been made to trace the ancestry of this king the political events that took place in his reign are discussed in detail. The fifth chapter discusses the historical developments that took place in the kingdom of Kotte after the death of Parakraonabahu VI up to the partition of the kingdom in 1521 as a result of the Vijayaba-kollaya. The sixth chapter deals mainly with the foundation of the kingdom of Udarata. The last chapter deals with the Portuguese activities in the Island during the earliest part of their stay in the Island

Evaluating hardening techniques against cryptanalysis attacks on Bloom filter encodings for record linkage

Introduction Due to privacy concerns personal identifiers used for linking data often have to be encoded (masked) before being linked across organisations. Bloom filter (BF) encoding is a popular privacy technique that is now employed in real-world linkage applications. Recent research has however shown that BFs are vulnerable to cryptanalysis attacks. Objectives and Approach Attacks on BFs either exploit that encoding frequent plain-text values (such as common names) results in corresponding frequent BFs, or they apply pattern mining to identify co-occurring BF bit positions that correspond to frequent encoded q-grams (sub-strings). In this study we empirically evaluated the privacy of individuals encoded in BFs against two recent cryptanalysis attack methods by Christen et al. (2017/2018). We used two snapshots of the North Carolina Voter Registration database for our evaluation, where pairs of records corresponding to the same voter (with name or address variations) resulted in files with 222,251 BFs and 224,061 plain-text records, respectively. Results We encoded between two and four of the fields first and last name, street, and city into one BF per record. For combinations of three and four fields all plain-text values and BFs were unique, challenging any frequency-based attack. For hardening BFs, different suggested methods (balancing, random hashing, XOR, BLIP, and salting) were applied. Without any hardening applied up to 20.7% and 5% of plain-text values were correctly re-identified as 1-to-1 matches by both the pattern-mining and frequency-based attack methods, respectively. No more than 5\% correct 1-to-1 re-identification matches were achieved with the frequency-based attack on BFs encoding two fields when either balancing, random hashing, or XOR folding was applied; while the pattern-mining based attack was not successful in any correct re-identifications for any hardening technique. Conclusion/Implications Given that BF encoding is now being employed in real-world linkage applications, it is important to study the limits of this privacy technique. Our experimental evaluation shows that although basic BFs without hardening technique are susceptible to cryptanalysis attacks, some hardening techniques are able to protect BFs against these attacks

Values of natural and human-made wetlands: A meta-analysis

The values of goods and services provided by wetland ecosystems are examined through a meta-analysis of an expanded database of wetland value estimates and with a focus on human-made wetlands. This study extends and improves upon previous meta-analyses of the wetland valuation literature in terms of the number of observations, geographical coverage, wetland class and integrity, and the measurement of the effects of scarcity and anthropogenic pressure. We find that water quality improvement, nonconsumptive recreation, and provision of natural habitat and biodiversity are highly valued services. Substitution effects are observed through the negative correlation between values and abundance of other wetlands. Wetland values are found to increase with anthropogenic pressure. An extended metaregression model with cross effects shows that the valuation of specific services varies with the type of wetland producing them. Human-made wetlands are highly valued for biodiversity enhancement, water quality improvement, and flood control

Record of the world’s biggest pangolin? New observations of bodyweight and total body length of the Indian Pangolin Manis crassicaudata Gray, 1827 (Mammalia: Pholidota: Manidae) from Mannar District, Sri Lanka

The Indian Pangolin Manis crassicaudata is one of the eight extant pangolin species in the world, occurring in the Indian subcontinent and is the solitary pangolin species recorded in Sri Lanka. Little is known about the intra-specific morphometric variations of the Indian Pangolin, largely due to the limited observations. In this note, we report the morphometrics of the largest Indian Pangolin recorded so far in its range, and consequently the largest pangolin ever to be recorded according to published information. These records along with observations from other range countries provide novel insights into the maximum growth of male Indian Pangolins

Metagenomics Uncovers a Core SAR11 Population in Brackish Surface Waters of the Baltic Sea

The Baltic Sea represents one of the largest brackish ecosystems where various environmental factors control dynamic seasonal shifts in the structure, diversity, and function of the planktonic microbial communities. In this study, despite seasonal fluctuations, several bacterial populations (<2% of the total OTUs) that are highly dominant (25% of relative abundance) and highly frequently occurring (>85% of occurrence) over four seasons were identified. Mathematical models using occurrence frequency and relative abundance data were able to describe community assembly persisting over time. Further, this work uncovered one of the core bacterial populations phylogenetically affiliated to SAR11 subclade IIIa. The analysis of the hypervariable region of 16S rRNA gene and single copy housekeeping genes recovered from metagenomic datasets suggested that the population was unexpectedly evolutionarily closely related to those inhabiting a mesosaline lacustrine ecosystem rather than other marine/coastal members. Our metagenomic results further revealed that the newly-identified population was the major driver facilitating the seasonal shifts in the overall community structure over the brackish waters of the Baltic Sea. The core community uncovered in this study supports the presence of a brackish water microbiome distinguishable from other marine and freshwater counterparts and will be a useful sentinel for monitoring local/global environmental changes posed on brackish surface waters