FPGAs for the Masses: Affordable Hardware Synthesis from Domain-Specific Languages

Field Programmable Gate Arrays (FPGAs) have the unique ability to be configured into application-specific architectures that are well suited to specific computing problems. This enables them to achieve performances and energy efficiencies that outclass other processor-based architectures, such as Chip Multiprocessors (CMPs), Graphic Processing Units (GPUs) and Digital Signal Processors (DSPs). Despite this, FPGAs are yet to gain widespread adoption, especially among application and software developers, because of their laborious application development process that requires hardware design expertise. In some application areas, domain-specific hardware synthesis tools alleviate this problem by using a Domain-Specific Language (DSL) to hide the low-level hardware details and also improve productivity of the developer. Additionally, these tools leverage domain knowledge to perform optimizations and produce high-quality hardware designs. While this approach holds great promise, the significant effort and cost of developing such domain-specific tools make it unaffordable in many application areas. In this thesis, we develop techniques to reduce the effort and cost of developing domain-specific hardware synthesis tools. To demonstrate our approach, we develop a toolchain to generate complete hardware systems from high-level functional specifications written in a DSL. Firstly, our approach uses language embedding and type-directed staging to develop a DSL and compiler in a cost-effective manner. To further reduce effort, we develop this compiler by composing reusable optimization modules, and integrate it with existing hardware synthesis tools. However, most synthesis tools require users to have hardware design knowledge to produce high-quality results. Therefore, secondly, to facilitate people without hardware design skills to develop domain-specific tools, we develop a methodology to generate high-quality hardware designs from well known computational patterns, such as map, zipWith, reduce and foreach; computational patterns are algorithmic methods that capture the nature of computation and communication and can be easily understood and used without expert knowledge. In our approach, we decompose the DSL specifications into constituent computational patterns and exploit the properties of these patterns, such as degree of parallelism, interdependence between operations and data-access characteristics, to generate high-quality hardware modules to implement them, and compose them into a complete system design. Lastly, we extended our methodology to automatically parallelize computations across multiple hardware modules to benefit from the spatial parallelism of the FPGA as well as overcome performance problems caused by non-sequential data access patterns and long access latency to external memory. To achieve this, we utilize the data-access properties of the computational patterns to automatically identify synchronization requirements and generate such multi-module designs from the same high-level functional specifications. Driven by power and performance constraints, today the world is turning to reconfigurable technology (i.e., FPGAs) to meet the computational needs of tomorrow. In this light, this work addresses the cardinal problem of making tomorrow's computing infrastructure programmable to application developers

S Transform: Time Frequency Analysis & Filtering

The S transform, a hybrid of the Short Time Fourier Transform and Wavelet transform, has a time frequency resolution which is far from ideal. This thesis proposes a modified S transform, which offers better time frequency resolution compared to the original S transform. The improvement is achieved through the introduction of a new scaling rule for the Gaussian window used in S transform. The S transform analysis of financial time series revealed the presence of business cycles, which could help forecasting economic booms and recessions. A noisy time series, with both signal and noise varying in frequency and in time, presents special challenges for improving the signal to noise ratio. The modified S-transform time-frequency representation is used to filter a synthetic time series in a two step filtering process. The filter method appears robust within a wide range of background noise levels. The new filtering approach developed was successfully applied for the identification of Post Glacial rebound in Eastern Canada

A Single Blinded Randomised Controlled Trial on the Efficacy of Adjunctive Collagen Cross-Linking in Healing of Suppurative Corneal Ulcers

INTRODUCTION: The cornea is the clear transparent dome shaped anterior-most part of the eyeball that serves as the major refracting surface for focusing of images on the retina. Infectious keratitis, or suppurative corneal ulcer, is characterized by a corneal epithelial defect with underlying stromal inflammation and destruction caused by multiplying organisms and their toxins. Associated uveal tissue and anterior chamber inflammation also occur. Collagen cross-linking (CXL), a procedure routinely used for control of progression of keratoconus, has been found to have beneficial effects on many types of corneal ulcers. An observational pilot study in our institution in 2013-2014, demonstrated a beneficial effect of CXL in suppurative corneal ulcers. OBJECTIVES: Primary objective: To determine the benefit of adjunctive collagen cross linking (cxl) in reduction of the “time to healing” of suppurative corneal ulcer. Secondary objectives: 1. To determine any difference in treatment failure rate (rates of perforation/keratoplasty/evisceration) of corneal ulcers treated with cxl as compared to the control group. 2. To assess the effect of risk factors (size of ulcer/diabetic status/type of organism)in outcome of corneal ulcer treatment with cxl compared to controls. METHODS: Study Design: Single-Blinded, Randomized, Controlled Clinical Trial conducted at Department of Ophthalmology, Christian Medical College, Schell Campus, Vellore. The study had two arms: Interventional group: Patients with infective corneal ulcer who satisfy the inclusion and exclusion criteria on standard medical therapy randomized to adjunctive COLLAGEN CROSS-LINKING (CXL) Comparative group: Patients with infective corneal ulcer who satisfy the inclusion and exclusion criteria on standard medical therapy randomized to SHAM CXL. Patients with suppurative corneal ulcers were admitted after routine microbiological analysis (scraping for smear and culture), and assessed on a daily basis to determine response to treatment. All patients who fit the inclusion and exclusion criteria and were randomized tointerventional and control group. Inclusion Criteria: 1. Adults greater than 18 years of age. 2. Corneal ulcer size of 2mm to 6mm. 3. Ulcer infiltrate depth upto 2/3 of the corneal thickness. 4. Smear and/or culture positive for fungus or bacteria. 5. Patients who are willing for inpatient care. Exclusion Criteria: 1. Suspected viral keratitis. 2. Suspected acanthamoeba keratitis. 3. Corneal thinning greater than 50% on clinical assessment at presentation. 4. Any pre-existing corneal pathology. 5. History of previous collagen cross-linking. 6. Patients who are unable or unwilling to give consent. RESULTS: Our pilot study conducted in 2014 showed clinically significant reduction in duration of healing post adjunctive treatment of corneal ulcers with CXL. The present study is a randomized control trial to study the effectiveness of crosslinking as an adjuvant therapy in healing of ulcers. 44 patients were recruited fitting the inclusion criteria and were randomized to an Intervention group and sham cross linking (Control) group. 17 patients in each group completed treatment. All patients received topical antimicrobial therapy. Within 48 hours of enrollment either crosslinking or placebo treatment was started. Each patient in the study group received maximum of three sessions of cross linking. Symptom relief and time of healing were noted. The results were compared between the Intervention group and the Control group. Both groups showed similar healing time of 29.85 days of healing of ulcers, as well as similar success and failure rates. There was no difference in the time of healing between the two groups. (p value = 0.918). Hence, this study does not suggest that collagen cross linking adds any benefit to the time taken to for fungal corneal ulcers to heal. CONCLUSION: 1.Collagen crosslinking has no benefit in reducing the time of healing of ulcers. 2.CXL does not reduce or increase the failure rate of corneal ulcers. 3. There was no correlation between size of ulcer/diabetic status/type of organism and the outcome of corneal ulcer treatment with CXL compared to controls

Virtualized execution runtime for FPGA accelerators in the cloud

FPGAs offer high performance coupled with energy efficiency, making them extremely attractive computational resources within a cloud ecosystem. However, to achieve this integration and make them easy to program, we first need to enable users with varying expertise to easily develop cloud applications that leverage FPGAs. With the growing size of FPGAs, allocating them monolithically to users can be wasteful due to potentially low device utilization. Hence, we also need to be able to dynamically share FPGAs among multiple users. To address these concerns, we propose a methodology and a runtime system that together simplify the FPGA application development process by providing: 1) a clean abstraction with high-level APIs for easy application development; 2) a simple execution model that supports both hardware and software execution; and 3) a shared memory-model which is convenient to use for the programmers. Akin to an operating system on a computer, our lightweight runtime system enables the simultaneous execution of multiple applications by virtualizing computational resources, i.e., FPGA resources and on-board memory, and offers protection facilities to isolate applications from each other. In this paper, we illustrate how these features can be developed in a lightweight manner and quantitatively evaluate the performance overhead they introduce on a small set of applications running on our proof of concept prototype. Our results demonstrate that these features only introduce marginal performance overheads. More importantly, by sharing resources for simultaneous execution of multiple user applications, our platform improves FPGA utilization and delivers higher aggregate throughput compared to accessing the device in a time-shared manner

Collaborative adaptive exponential linear-in-the-parameters nonlinear filters

by Vinal Patel, Somanath Pradhan and Nithin V. Georg

Car Cabin Co2, A Safety Issue

Indoor Air Quality has become an important human health and safety concern, clean air is essential for good health. Many studies demonstrate that air recirculation can reduce exposure to nanoparticles in vehicle cabins. However when people occupy confined spaces, air recirculation can lead to carbon dioxide (CO2) accumulation which can potentially lead to deleterious effects on cognitive function. It is known that in-vehicle CO2 concentration tends to increase due to occupant exhalation when the HVAC (Heating, Ventilation and Air Conditioning) air is in recirculation mode. This study establishes a major safety problem associated with automotive; Field experiments were conducted to measure CO2 concentration in a typical automotive cabin

Measuring routine childhood vaccination coverage in 204 countries and territories, 1980-2019 : a systematic analysis for the Global Burden of Disease Study 2020, Release 1

Background Measuring routine childhood vaccination is crucial to inform global vaccine policies and programme implementation, and to track progress towards targets set by the Global Vaccine Action Plan (GVAP) and Immunization Agenda 2030. Robust estimates of routine vaccine coverage are needed to identify past successes and persistent vulnerabilities. Drawing from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2020, Release 1, we did a systematic analysis of global, regional, and national vaccine coverage trends using a statistical framework, by vaccine and over time. Methods For this analysis we collated 55 326 country-specific, cohort-specific, year-specific, vaccine-specific, and dosespecific observations of routine childhood vaccination coverage between 1980 and 2019. Using spatiotemporal Gaussian process regression, we produced location-specific and year-specific estimates of 11 routine childhood vaccine coverage indicators for 204 countries and territories from 1980 to 2019, adjusting for biases in countryreported data and reflecting reported stockouts and supply disruptions. We analysed global and regional trends in coverage and numbers of zero-dose children (defined as those who never received a diphtheria-tetanus-pertussis [DTP] vaccine dose), progress towards GVAP targets, and the relationship between vaccine coverage and sociodemographic development. Findings By 2019, global coverage of third-dose DTP (DTP3; 81.6% [95% uncertainty interval 80.4-82 .7]) more than doubled from levels estimated in 1980 (39.9% [37.5-42.1]), as did global coverage of the first-dose measles-containing vaccine (MCV1; from 38.5% [35.4-41.3] in 1980 to 83.6% [82.3-84.8] in 2019). Third- dose polio vaccine (Pol3) coverage also increased, from 42.6% (41.4-44.1) in 1980 to 79.8% (78.4-81.1) in 2019, and global coverage of newer vaccines increased rapidly between 2000 and 2019. The global number of zero-dose children fell by nearly 75% between 1980 and 2019, from 56.8 million (52.6-60. 9) to 14.5 million (13.4-15.9). However, over the past decade, global vaccine coverage broadly plateaued; 94 countries and territories recorded decreasing DTP3 coverage since 2010. Only 11 countries and territories were estimated to have reached the national GVAP target of at least 90% coverage for all assessed vaccines in 2019. Interpretation After achieving large gains in childhood vaccine coverage worldwide, in much of the world this progress was stalled or reversed from 2010 to 2019. These findings underscore the importance of revisiting routine immunisation strategies and programmatic approaches, recentring service delivery around equity and underserved populations. Strengthening vaccine data and monitoring systems is crucial to these pursuits, now and through to 2030, to ensure that all children have access to, and can benefit from, lifesaving vaccines. Copyright (C) 2021 The Author(s). Published by Elsevier Ltd.Peer reviewe

Spatial, temporal, and demographic patterns in prevalence of smoking tobacco use and attributable disease burden in 204 countries and territories, 1990-2019 : a systematic analysis from the Global Burden of Disease Study 2019

Background Ending the global tobacco epidemic is a defining challenge in global health. Timely and comprehensive estimates of the prevalence of smoking tobacco use and attributable disease burden are needed to guide tobacco control efforts nationally and globally. Methods We estimated the prevalence of smoking tobacco use and attributable disease burden for 204 countries and territories, by age and sex, from 1990 to 2019 as part of the Global Burden of Diseases, Injuries, and Risk Factors Study. We modelled multiple smoking-related indicators from 3625 nationally representative surveys. We completed systematic reviews and did Bayesian meta-regressions for 36 causally linked health outcomes to estimate non-linear dose-response risk curves for current and former smokers. We used a direct estimation approach to estimate attributable burden, providing more comprehensive estimates of the health effects of smoking than previously available. Findings Globally in 2019, 1.14 billion (95% uncertainty interval 1.13-1.16) individuals were current smokers, who consumed 7.41 trillion (7.11-7.74) cigarette-equivalents of tobacco in 2019. Although prevalence of smoking had decreased significantly since 1990 among both males (27.5% [26. 5-28.5] reduction) and females (37.7% [35.4-39.9] reduction) aged 15 years and older, population growth has led to a significant increase in the total number of smokers from 0.99 billion (0.98-1.00) in 1990. Globally in 2019, smoking tobacco use accounted for 7.69 million (7.16-8.20) deaths and 200 million (185-214) disability-adjusted life-years, and was the leading risk factor for death among males (20.2% [19.3-21.1] of male deaths). 6.68 million [86.9%] of 7.69 million deaths attributable to smoking tobacco use were among current smokers. Interpretation In the absence of intervention, the annual toll of 7.69 million deaths and 200 million disability-adjusted life-years attributable to smoking will increase over the coming decades. Substantial progress in reducing the prevalence of smoking tobacco use has been observed in countries from all regions and at all stages of development, but a large implementation gap remains for tobacco control. Countries have a dear and urgent opportunity to pass strong, evidence-based policies to accelerate reductions in the prevalence of smoking and reap massive health benefits for their citizens. Copyright (C) 2021 The Author(s). Published by Elsevier Ltd.Peer reviewe

Global burden of 369 diseases and injuries in 204 countries and territories, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019

Background: In an era of shifting global agendas and expanded emphasis on non-communicable diseases and injuries along with communicable diseases, sound evidence on trends by cause at the national level is essential. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) provides a systematic scientific assessment of published, publicly available, and contributed data on incidence, prevalence, and mortality for a mutually exclusive and collectively exhaustive list of diseases and injuries. Methods: GBD estimates incidence, prevalence, mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) due to 369 diseases and injuries, for two sexes, and for 204 countries and territories. Input data were extracted from censuses, household surveys, civil registration and vital statistics, disease registries, health service use, air pollution monitors, satellite imaging, disease notifications, and other sources. Cause-specific death rates and cause fractions were calculated using the Cause of Death Ensemble model and spatiotemporal Gaussian process regression. Cause-specific deaths were adjusted to match the total all-cause deaths calculated as part of the GBD population, fertility, and mortality estimates. Deaths were multiplied by standard life expectancy at each age to calculate YLLs. A Bayesian meta-regression modelling tool, DisMod-MR 2.1, was used to ensure consistency between incidence, prevalence, remission, excess mortality, and cause-specific mortality for most causes. Prevalence estimates were multiplied by disability weights for mutually exclusive sequelae of diseases and injuries to calculate YLDs. We considered results in the context of the Socio-demographic Index (SDI), a composite indicator of income per capita, years of schooling, and fertility rate in females younger than 25 years. Uncertainty intervals (UIs) were generated for every metric using the 25th and 975th ordered 1000 draw values of the posterior distribution. Findings: Global health has steadily improved over the past 30 years as measured by age-standardised DALY rates. After taking into account population growth and ageing, the absolute number of DALYs has remained stable. Since 2010, the pace of decline in global age-standardised DALY rates has accelerated in age groups younger than 50 years compared with the 1990–2010 time period, with the greatest annualised rate of decline occurring in the 0–9-year age group. Six infectious diseases were among the top ten causes of DALYs in children younger than 10 years in 2019: lower respiratory infections (ranked second), diarrhoeal diseases (third), malaria (fifth), meningitis (sixth), whooping cough (ninth), and sexually transmitted infections (which, in this age group, is fully accounted for by congenital syphilis; ranked tenth). In adolescents aged 10–24 years, three injury causes were among the top causes of DALYs: road injuries (ranked first), self-harm (third), and interpersonal violence (fifth). Five of the causes that were in the top ten for ages 10–24 years were also in the top ten in the 25–49-year age group: road injuries (ranked first), HIV/AIDS (second), low back pain (fourth), headache disorders (fifth), and depressive disorders (sixth). In 2019, ischaemic heart disease and stroke were the top-ranked causes of DALYs in both the 50–74-year and 75-years-and-older age groups. Since 1990, there has been a marked shift towards a greater proportion of burden due to YLDs from non-communicable diseases and injuries. In 2019, there were 11 countries where non-communicable disease and injury YLDs constituted more than half of all disease burden. Decreases in age-standardised DALY rates have accelerated over the past decade in countries at the lower end of the SDI range, while improvements have started to stagnate or even reverse in countries with higher SDI. Interpretation: As disability becomes an increasingly large component of disease burden and a larger component of health expenditure, greater research and developm nt investment is needed to identify new, more effective intervention strategies. With a rapidly ageing global population, the demands on health services to deal with disabling outcomes, which increase with age, will require policy makers to anticipate these changes. The mix of universal and more geographically specific influences on health reinforces the need for regular reporting on population health in detail and by underlying cause to help decision makers to identify success stories of disease control to emulate, as well as opportunities to improve. Funding: Bill & Melinda Gates Foundation. © 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licens

Measuring universal health coverage based on an index of effective coverage of health services in 204 countries and territories, 1990–2019 : A systematic analysis for the Global Burden of Disease Study 2019

Background Achieving universal health coverage (UHC) involves all people receiving the health services they need, of high quality, without experiencing financial hardship. Making progress towards UHC is a policy priority for both countries and global institutions, as highlighted by the agenda of the UN Sustainable Development Goals (SDGs) and WHO's Thirteenth General Programme of Work (GPW13). Measuring effective coverage at the health-system level is important for understanding whether health services are aligned with countries' health profiles and are of sufficient quality to produce health gains for populations of all ages. Methods Based on the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, we assessed UHC effective coverage for 204 countries and territories from 1990 to 2019. Drawing from a measurement framework developed through WHO's GPW13 consultation, we mapped 23 effective coverage indicators to a matrix representing health service types (eg, promotion, prevention, and treatment) and five population-age groups spanning from reproductive and newborn to older adults (≥65 years). Effective coverage indicators were based on intervention coverage or outcome-based measures such as mortality-to-incidence ratios to approximate access to quality care; outcome-based measures were transformed to values on a scale of 0–100 based on the 2·5th and 97·5th percentile of location-year values. We constructed the UHC effective coverage index by weighting each effective coverage indicator relative to its associated potential health gains, as measured by disability-adjusted life-years for each location-year and population-age group. For three tests of validity (content, known-groups, and convergent), UHC effective coverage index performance was generally better than that of other UHC service coverage indices from WHO (ie, the current metric for SDG indicator 3.8.1 on UHC service coverage), the World Bank, and GBD 2017. We quantified frontiers of UHC effective coverage performance on the basis of pooled health spending per capita, representing UHC effective coverage index levels achieved in 2019 relative to country-level government health spending, prepaid private expenditures, and development assistance for health. To assess current trajectories towards the GPW13 UHC billion target—1 billion more people benefiting from UHC by 2023—we estimated additional population equivalents with UHC effective coverage from 2018 to 2023. Findings Globally, performance on the UHC effective coverage index improved from 45·8 (95% uncertainty interval 44·2–47·5) in 1990 to 60·3 (58·7–61·9) in 2019, yet country-level UHC effective coverage in 2019 still spanned from 95 or higher in Japan and Iceland to lower than 25 in Somalia and the Central African Republic. Since 2010, sub-Saharan Africa showed accelerated gains on the UHC effective coverage index (at an average increase of 2·6% [1·9–3·3] per year up to 2019); by contrast, most other GBD super-regions had slowed rates of progress in 2010–2019 relative to 1990–2010. Many countries showed lagging performance on effective coverage indicators for non-communicable diseases relative to those for communicable diseases and maternal and child health, despite non-communicable diseases accounting for a greater proportion of potential health gains in 2019, suggesting that many health systems are not keeping pace with the rising non-communicable disease burden and associated population health needs. In 2019, the UHC effective coverage index was associated with pooled health spending per capita (r=0·79), although countries across the development spectrum had much lower UHC effective coverage than is potentially achievable relative to their health spending. Under maximum efficiency of translating health spending into UHC effective coverage performance, countries would need to reach $1398 pooled health spending per capita (US$ adjusted for purchasing power parity) in order to achieve 80 on the UHC effective coverage index. From 2018 to 2023, an estimated 388·9 million (358·6–421·3) more population equivalents would have UHC effective coverage, falling well short of the GPW13 target of 1 billion more people benefiting from UHC during this time. Current projections point to an estimated 3·1 billion (3·0–3·2) population equivalents still lacking UHC effective coverage in 2023, with nearly a third (968·1 million [903·5–1040·3]) residing in south Asia. Interpretation The present study demonstrates the utility of measuring effective coverage and its role in supporting improved health outcomes for all people—the ultimate goal of UHC and its achievement. Global ambitions to accelerate progress on UHC service coverage are increasingly unlikely unless concerted action on non-communicable diseases occurs and countries can better translate health spending into improved performance. Focusing on effective coverage and accounting for the world's evolving health needs lays the groundwork for better understanding how close—or how far—all populations are in benefiting from UHC