Indiana University-Purdue University Indianapolis (IUPUI) / Women are underrepresented in science, technology, engineering, and math fields (STEM), especially in higher levels. Researchers term this phenomenon "the leaky pipeline." While the issue is well-documented in the literature, little is known about its antecedents. The current study offers insight into factors that relate to career choice and contribute to the lack of diversity in STEM fields by investigating how sense of belonging and psychological capital (PsyCap) influence important psychological, academic, and career outcomes for women in these fields. Female undergraduate STEM majors were recruited for participation at two times during the fall academic semester (N=182 at time one, N=86 at time two) and data were analyzed using correlation and regression. Results provide support for the influence of both sense of belonging and PsyCap as important correlates of an individual's academic and career making decisions. Specifically, PsyCap mediated the relationship between belonging and well-being and belonging and career outcomes of engagement and participants' intentions to apply to graduate programs in an unrelated major. In addition, PsyCap moderated the relationship between sense of belonging and participants' intentions to switch majors and intentions to apply to graduate programs in a field unrelated to their current major. An increased understanding of the factors that contribute to the leaky pipeline in STEM will serve as a basis for developing further research questions and targeting interventions.

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Germany’s commitment to carbon neutrality by 2045 underscores the need for climate action, with hydrogen’s multiple uses in industry, transport, and energy offering a viable solution. Efficient retrofitting of the extensive natural gas pipeline network can enable hydrogen to be transported from supply to demand centers. The aim of this study is to develop a hydrogen pipeline network strategy for Germany in 2045 that is consistent with carbon neutrality goals while minimizing associated costs. Using a single-period deterministic Mixed Integer Linear Programming (MILP) approach, the focus is on estimating peak-hour transport demand derived from the spatial distribution of demand and supply. This estimation is based on openly available data from the Germany Energy Agency (dena) pilot study on carbon neutrality. The methodology aims to allocate hydrogen energy flows along existing pipelines through a retrofitting approach. The base scenario is derived from the projected hydrogen demand and supply for a carbon-neutral Germany in 2045, as estimated in the dena pilot study. To explore different possibilities, a sensitivity analysis compares five different demand scenarios. Each scenario examines different hard-to-abate subsectors that have limited options for decarbonization. Evaluating the routes and utilization rates across the pipeline network provides insights into the feasibility, with certain routes, particularly those originating in the north, emerging as key. The majority of pipelines in the network have low utilization rates below 25% in peak hours, which may indicate economic infeasibility or the need for alternative transport strategies. In addition, a cost of avoided emissions analysis weighs scenario-specific emission reductions against network costs. Of particular note is the network connecting CHP plants and energy-intensive industries, which appears to strike an optimal balance in terms of costs of avoided emissions and utilization rate in peak hours. Nevertheless, the study does not consider physical flow calculations, so further validation is required in this respect. The potential of the methodology, however, liesin its ability to quickly assess different scenarios and provide valuable insights into economic, environmental, and social impacts. / Tysklands åtagande om koldioxidneutralitet senast 2045 understryker behovet av klimatåtgärder, och vätgasens många användningsområden inom industri, transport och energi erbjuder en hållbar lösning. Effektiv eftermontering av det omfattande naturgasledningsnätet kan göra det möjligt att transportera vätgas från utbuds- till efterfrågecentra. Syftet med denna studie är att utveckla en strategi för vätgasnätet i Tyskland 2045 som är förenlig med målen för koldioxidneutralitet och samtidigt minimerar de tillhörande kostnaderna. Med hjälp av en deterministisk MILP-metod (Mixed Integer Linear Programming) för en enda period ligger fokus på att uppskatta efterfrågan på transporter under maxtimmar utifrån den rumsliga fördelningen av efterfrågan och utbud. Denna uppskattning baseras på öppet tillgängliga data från denas pilotstudie om koldioxidneutralitet. Metoden syftar till att fördela vätgasenergiflöden längs befintliga rörledningar genom en eftermonteringsstrategi. Det grundläggande scenariot härleds från den beräknade efterfrågan och tillgången på vätgas för ett koldioxidneutralt Tyskland 2045, enligt uppskattningar i dena-pilotstudien. För att utforska olika möjligheter jämförs fem olika efterfrågescenarier i en känslighetsanalys. Varje scenario undersöker olika delsektorer som är svåra att minska och som har begränsade alternativ för utfasning av fossila bränslen. Utvärderingen av sträckningarna och utnyttjandegraden i rörledningsnätet ger insikter om genomförbarheten, där vissa sträckningar, särskilt de med ursprung i norr, framstår som viktiga. Majoriteten av rörledningarna i nätverkethar låga nyttjandegrader under 25% under rusningstid, vilket kan indikera ekonomisk ogenomförbarhet eller behovet av alternativa transportstrategier. Dessutom väger en kostnads-/nyttoanalys av utsläpp scenariospecifika utsläppsminskningar mot nätverkskostnader. Särskilt värt att notera är det nätverk som förbinder kraftvärmeverk och energiintensiva industrier, vilket verkar ge en optimal balans när det gäller kostnader för utsläpp och nyttjandegrad. Studien tar dock inte hänsyn till fysiska flödesberäkningar, så ytterligare validering krävs i detta avseende. Metodens potential ligger dock i dess förmåga att snabbt bedöma olika scenarier och ge värdefulla insikter om ekonomiska, miljömässiga och sociala effekter.

Relational database systems provide various services and applications with an efficient means for storing, processing, and retrieving their data. The performance of these systems has a direct impact on the quality of service of the applications that rely on them. Therefore, it is crucial that database systems are able to adapt and grow in tandem with the demands of these applications, ensuring that their performance scales accordingly. In the past, Moore's law and algorithmic advancements have been sufficient to meet these demands. However, with the slowdown of Moore's law, researchers have begun exploring alternative methods, such as application-specific technologies, to satisfy the more challenging performance requirements. One such technology is field-programmable gate arrays (FPGAs), which provide ideal platforms for developing and running custom architectures for accelerating database systems. The goal of this thesis is to develop a domain-specific architecture that can enhance the performance of in-memory database systems when executing analytical queries. Our research is guided by a combination of academic and industrial requirements that seek to strike a balance between generality and performance. The former ensures that our platform can be used to process a diverse range of workloads, while the latter makes it an attractive solution for high-performance use cases. Throughout this thesis, we present the development of a system-on-chip for database system acceleration that meets our requirements. The resulting architecture, called CbMSMK, is capable of processing the projection, sort, aggregation, and equi-join database operators and can also run some complex TPC-H queries. CbMSMK employs a shared sort-merge pipeline for executing all these operators, which results in an efficient use of FPGA resources. This approach enables the instantiation of multiple acceleration cores on the FPGA, allowing it to serve multiple clients simultaneously. CbMSMK can process both arbitrarily deep and wide tables efficiently. The former is achieved through the use of the sort-merge algorithm which utilizes the FPGA RAM for buffering intermediate sort results. The latter is achieved through the use of KeRRaS, a novel variant of the forward radix sort algorithm introduced in this thesis. KeRRaS allows CbMSMK to process a table a few columns at a time, incrementally generating the final result through multiple iterations. Given that acceleration is a key objective of our work, CbMSMK benefits from many performance optimizations. For instance, multi-way merging is employed to reduce the number of merge passes required for the execution of the sort-merge algorithm, thus improving the performance of all our pipeline-breaking operators. Another example is our in-depth analysis of early aggregation, which led to the development of a novel cache-based algorithm that significantly enhances aggregation performance. Our experiments demonstrate that CbMSMK performs on average 5 times faster than the state-of-the-art CPU-based database management system MonetDB.:I Database Systems & FPGAs 1 INTRODUCTION 1.1 Databases & the Importance of Performance 1.2 Accelerators & FPGAs 1.3 Requirements 1.4 Outline & Summary of Contributions 2 BACKGROUND ON DATABASE SYSTEMS 2.1 Databases 2.1.1 Storage Model 2.1.2 Storage Medium 2.2 Database Operators 2.2.1 Projection 2.2.2 Filter 2.2.3 Sort 2.2.4 Aggregation 2.2.5 Join 2.2.6 Operator Classification 2.3 Database Queries 2.4 Impact of Acceleration 3 BACKGROUND ON FPGAS 3.1 FPGA 3.1.1 Logic Element 3.1.2 Block RAM (BRAM) 3.1.3 Digital Signal Processor (DSP) 3.1.4 IO Element 3.1.5 Programmable Interconnect 3.2 FPGADesignFlow 3.2.1 Specifications 3.2.2 RTL Description 3.2.3 Verification 3.2.4 Synthesis, Mapping, Placement, and Routing 3.2.5 TimingAnalysis 3.2.6 Bitstream Generation and FPGA Programming 3.3 Implementation Quality Metrics 3.4 FPGA Cards 3.5 Benefits of Using FPGAs 3.6 Challenges of Using FPGAs 4 RELATED WORK 4.1 Summary of Related Work 4.2 Platform Type 4.2.1 Accelerator Card 4.2.2 Coprocessor 4.2.3 Smart Storage 4.2.4 Network Processor 4.3 Implementation 4.3.1 Loop-based implementation 4.3.2 Sort-based Implementation 4.3.3 Hash-based Implementation 4.3.4 Mixed Implementation 4.4 A Note on Quantitative Performance Comparisons II Cache-Based Morphing Sort-Merge with KeRRaS (CbMSMK) 5 OBJECTIVES AND ARCHITECTURE OVERVIEW 5.1 From Requirements to Objectives 5.2 Architecture Overview 5.3 Outlineof Part II 6 COMPARATIVE ANALYSIS OF OPENCL AND RTL FOR SORT-MERGE PRIMITIVES ON FPGAS 6.1 Programming FPGAs 6.2 RelatedWork 6.3 Architecture 6.3.1 Global Architecture 6.3.2 Sorter Architecture 6.3.3 Merger Architecture 6.3.4 Scalability and Resource Adaptability 6.4 Experiments 6.4.1 OpenCL Sort-Merge Implementation 6.4.2 RTLSorters 6.4.3 RTLMergers 6.4.4 Hybrid OpenCL-RTL Sort-Merge Implementation 6.5 Summary & Discussion 7 RESOURCE-EFFICIENT ACCELERATION OF PIPELINE-BREAKING DATABASE OPERATORS ON FPGAS 7.1 The Case for Resource Efficiency 7.2 Related Work 7.3 Architecture 7.3.1 Sorters 7.3.2 Sort-Network 7.3.3 X:Y Mergers 7.3.4 Merge-Network 7.3.5 Join Materialiser (JoinMat) 7.4 Experiments 7.4.1 Experimental Setup 7.4.2 Implementation Description & Tuning 7.4.3 Sort Benchmarks 7.4.4 Aggregation Benchmarks 7.4.5 Join Benchmarks 7. Summary 8 KERRAS: COLUMN-ORIENTED WIDE TABLE PROCESSING ON FPGAS 8.1 The Scope of Database System Accelerators 8.2 Related Work 8.3 Key-Reduce Radix Sort(KeRRaS) 8.3.1 Time Complexity 8.3.2 Space Complexity (Memory Utilization) 8.3.3 Discussion and Optimizations 8.4 Architecture 8.4.1 MSM 8.4.2 MSMK: Extending MSM with KeRRaS 8.4.3 Payload, Aggregation and Join Processing 8.4.4 Limitations 8.5 Experiments 8.5.1 Experimental Setup 8.5.2 Datasets 8.5.3 MSMK vs. MSM 8.5.4 Payload-Less Benchmarks 8.5.5 Payload-Based Benchmarks 8.5.6 Flexibility 8.6 Summary 9 A STUDY OF EARLY AGGREGATION IN DATABASE QUERY PROCESSING ON FPGAS 9.1 Early Aggregation 9.2 Background & Related Work 9.2.1 Sort-Based Early Aggregation 9.2.2 Cache-Based Early Aggregation 9.3 Simulations 9.3.1 Datasets 9.3.2 Metrics 9.3.3 Sort-Based Versus Cache-Based Early Aggregation 9.3.4 Comparison of Set-Associative Caches 9.3.5 Comparison of Cache Structures 9.3.6 Comparison of Replacement Policies 9.3.7 Cache Selection Methodology 9.4 Cache System Architecture 9.4.1 Window Aggregator 9.4.2 Compressor & Hasher 9.4.3 Collision Detector 9.4.4 Collision Resolver 9.4.5 Cache 9.5 Experiments 9.5.1 Experimental Setup 9.5.2 Resource Utilization and Parameter Tuning 9.5.3 Datasets 9.5.4 Benchmarks on Synthetic Data 9.5.5 Benchmarks on Real Data 9.6 Summary 10 THE FULL PICTURE 10.1 System Architecture 10.2 Benchmarks 10.3 Meeting the Objectives III Conclusion 11 SUMMARY AND OUTLOOK ON FUTURE RESEARCH 11.1 Summary 11.2 Future Work BIBLIOGRAPHY LIST OF FIGURES LIST OF TABLES

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This dissertation examines the contestations over the politics of knowledge, risk, and environmental justice in three fenceline sites. Mobilizing the fenceline standpoint to study risk strengthens our objective understanding of the social situatedness of risk. To illustrate how a fenceline standpoint contributes to stronger objectivity of risk contestations, I survey public discourse of coal slurry extraction in Black Mesa, Arizona using an environmental justice framework. Discursive justifications for the construction of the slurry pipeline reveal how environmental injustice in the fenceline community emerged through urban controversies over water and power generation that excluded a fenceline standpoint. Insights from Black Mesa frame the next two cases: open burning hazardous waste at Radford Army Ammunition Plant, and M6 Disposal at Camp Minden, Louisiana. At Radford, scholar-activist research examines the contestations of risk at one of the most hazardous waste facilities in the nation. I analyze the construction of risk from open burning of hazardous waste from a fenceline standpoint. I discursively situate the controversy over fenceline community risk from open burning, by showing the inadequacies of official risk assessments. Critical discourse analysis of risk shows the extant contestations over the practice of open burning. In juxtaposition to Radford, the Camp Minden open burn controversy demonstrates how a fenceline movement successfully constructed alternatives to open burning. Fenceline success in Minden is forcing scrutiny over the risks produced by the practice of open burning explosives across the United States. The activation of fenceline knowledge and expertise, through grassroots organizing, is propelling inquiry from scientific and technical experts of the American Chemical Society who are questioning why the Department of Defense and the Environmental Protection Agency have approved the use of open burning at other sites despite safer alternative technology. Synthetically, each case illustrates the importance of fenceline knowledge as a crucial site of expertise. I present an argument for how a fenceline standpoint can challenge regulatory and producer constructions of fenceline risk. The creation of a program of research: Critical Risk Analysis, offers a model for scholar-activist intervention on the fenceline. The Camp Minden Dialogue demonstrates a successful example of how fenceline expert-activists can influence the construction of risk. Normatively, I build the argument that environmental justice research within Science and Technology Studies ought to situate the fenceline standpoint as equal to the competing epistemological claims of production and regulatory experts in order to strengthen the objectivity of our research in contested fenceline sites. / Ph. D.