Todd R . Green | National commission for mass literacy adult and non formal education (original) (raw)

Papers by Todd R . Green

Proceedings of the twenty-seventh ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems - PODS '08, 2008

ABSTRACT We present a formal framework,for capturing the provenance,of data appearing in XQuery v... more ABSTRACT We present a formal framework,for capturing the provenance,of data appearing in XQuery views of XML. Building on previous work on relations and their (positive) query languages, we dec- orate unordered XML with annotations from commutative,semir- ings and show,that these annotations suffice for a large positive fragment of XQuery applied to this data. In addition to tracking provenance metadata, the

Vaccines, 2021

The coronavirus disease 2019 (COVID-19) pandemic has highlighted the urgent need for effective pr... more The coronavirus disease 2019 (COVID-19) pandemic has highlighted the urgent need for effective prophylactic vaccination to prevent the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Intranasal vaccination is an attractive strategy to prevent COVID-19 as the nasal mucosa represents the first-line barrier to SARS-CoV-2 entry. The current intramuscular vaccines elicit systemic immunity but not necessarily high-level mucosal immunity. Here, we tested a single intranasal dose of our candidate adenovirus type 5-vectored vaccine encoding the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein (AdCOVID) in inbred, outbred, and transgenic mice. A single intranasal vaccination with AdCOVID elicited a strong and focused immune response against RBD through the induction of mucosal IgA in the respiratory tract, serum neutralizing antibodies, and CD4+ and CD8+ T cells with a Th1-like cytokine expression profile. A single AdCOVID dose resulted in immunity that wa...

Journal of Virology, 2018

The HIV-1 envelope (Env) glycans shield the surface of Env from the immune system and form integr... more The HIV-1 envelope (Env) glycans shield the surface of Env from the immune system and form integral interactions important for a functional Env. To understand how individual N-glycosylation sites (NGS) coordinate to form a dynamic shield and evade the immune system through mutations, we tracked 20 NGS in Env from HIV-transmitted/founder (T/F) and immune escape variants and their mutants involving the N262 glycan. NGS were profiled in a site-specific manner using a high-resolution mass spectrometry (MS)-based workflow. Using this site-specific quantitative heterogeneity profiling, we empirically characterized the interdependent NGS of a microdomain in the high-mannose patch (HMP). The changes (shifts) in NGS heterogeneity between the T/F and immune escape variants defined a range of NGS that we further probed for exclusive combinations of sequons in the HMP microdomain using the Los Alamos National Laboratory HIV sequence database. The resultant sequon combinations, including the hig...

Foundations and Trends® in Databases, 2012

In recent years, we have witnessed a revival of the use of recursive queries in a variety of emer... more In recent years, we have witnessed a revival of the use of recursive queries in a variety of emerging application domains such as data integration and exchange, information extraction, networking, and program analysis. A popular language used for expressing these queries is Datalog. This paper surveys for a general audience the Datalog language, recursive query processing, and optimization techniques. This survey differs from prior surveys written in the eighties and nineties in its comprehensiveness of topics, its coverage of recent developments and applications, and its emphasis on features and techniques beyond "classical" Datalog which are vital for practical applications. Specifically, the topics covered include the core Datalog language and various extensions, semantics, query optimizations, magic-sets optimizations, incremental view maintenance, aggregates, negation, and types. We conclude the paper with a survey of recent systems and applications that use Datalog and recursive queries.

Proceedings of the 2011 international conference on Management of data - SIGMOD '11, 2011

We are witnessing an exciting revival of interest in recursive Datalog queries in a variety of em... more We are witnessing an exciting revival of interest in recursive Datalog queries in a variety of emerging application domains such as data integration, information extraction, networking, program analysis, security, and cloud computing. This tutorial briefly reviews the Datalog language and recursive query processing and optimization techniques, then discusses applications of Datalog in three application domains: data integration, declarative networking, and program analysis. Throughout the tutorial, we use LogicBlox, a commercial Datalog engine for enterprise software systems, to allow the audience to walk through code examples presented in the tutorial.

Measurement and Control, 2008

The principle of injecting gases such as N2 and CO2 into oilfields to manage reservoir resources ... more The principle of injecting gases such as N2 and CO2 into oilfields to manage reservoir resources is well understood. The Yates Field — a mature site in West Texas — presented Kinder Morgan with particular difficulties, with the requirement to inject low pressure CO2 with flow control and measurement at the well-head. The low pressure and high ambient temperatures lead to almost continuous flashing, with gas void fractions (GVFs) estimated to range between 0% and 80%. A solar and wind powered station was designed around a two-phase capable Coriolis mass flow meter. As well as metering the flow, the station controls it using a modulating valve, based on the two-phase flow measurement. A wireless communication system maintains contact with the central control. Some 20 stations have been operating successfully for four years, enabling effective reservoir management techniques.

Lecture Notes in Computer Science, 2012

The modern enterprise software stack-a collection of applications supporting bookkeeping, analyti... more The modern enterprise software stack-a collection of applications supporting bookkeeping, analytics, planning, and forecasting for enterprise data-is in danger of collapsing under its own weight. The task of building and maintaining enterprise software is tedious and laborious; applications are cumbersome for end-users; and adapting to new computing hardware and infrastructures is difficult. We believe that much of the complexity in today's architecture is accidental, rather than inherent. This tutorial provides an overview of the LogicBlox platform, a ambitious redesign of the enterprise software stack centered around a unified declarative programming model, based on an extended version of Datalog. 1 The Enterprise Hairball Modern enterprise applications involve an enormously complex technology stack composed of many disparate systems programmed in a hodgepodge of programming languages. We refer to this stack, depicted in Figure 1, as "the enterprise hairball." First, there is an online transaction processing (OLTP) layer that performs bookkeeping of the core business data for an enterprise. Such data could include the current product catalog, recent sales figures, current outstanding invoices, customer account balances, and so forth. This OLTP layer typically includes a relational DBMS-programmed in a combination of a query language (SQL), a stored procedure language (like PL/SQL or TSQL), and a batch programming language like Pro*C-an application server, such as Oracle WebLogic [35], IBM WebSphere [36], or SAP NetWeaver [26]-programmed in an object-oriented language like Java, C#, or ABAP-and a web browser front-end, programmed using HTML and Javascript. In order to track the performance of the enterprise over time, a second business intelligence (BI) layer typically holds five to ten years of historical information that was originally recorded in the OLTP layer and performs read-only analyses on this information. This layer typically includes another DBMS (or, more commonly, a BI variant like Teradata [33] or IBM Netezza [25]) along with a BI application server such as Microstrategy [23], SAP BusinessObjects [5], or IBM Cognos [7], programmed using a vendor-specific declarative language.

2008 IEEE Aerospace Conference, 2008

Over the past fifteen years, Goddard Space Flight Center has developed several successful science... more Over the past fifteen years, Goddard Space Flight Center has developed several successful science missions in-house: the Wilkinson Microwave Anisotropy Probe (WMAP), the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE), the Earth Observing 1 (EO-1) [1], and the Space Technology 5 (ST-5) [2] missions, several Small Explorers, and several balloon missions. Currently in development are the Solar Dynamics Observatory (SDO) [3] and the Lunar Reconnaissance Orbiter (LRO) [4]. What is not well known is that these missions have been supported during spacecraft and/or instrument integration and test, flight software development, and mission operations by two in house satellite Telemetry and Command (T&C) systems, the Integrated Test and Operations System (ITOS) and the Advanced Spacecraft Integration and System Test (ASIST).

2012 IEEE 28th International Conference on Data Engineering, 2012

A major challenge faced by today's information systems is that of evolution as data usage evolves... more A major challenge faced by today's information systems is that of evolution as data usage evolves or new data resources become available. Modern organizations sometimes exchange data with one another via declarative mappings among their databases, as in data exchange and collaborative data sharing systems. Such mappings are frequently revised and refined as new data becomes available, new cross-reference tables are created, and corrections are made. A fundamental question is how to handle changes to these mapping definitions, when the organizations each materialize the results of applying the mappings to the available data. We consider how to incrementally recompute these database instances in this setting, reusing (if possible) previously computed instances to speed up computation. We develop a principled solution that performs cost-based exploration of recomputation versus reuse, and simultaneously handles updates to source data and mapping definitions through a single, unified mechanism. Our solution also takes advantage of provenance information, when present, to speed up computation even further. We present an implementation that takes advantage of an off-the-shelf DBMS's query processing system, and we show experimentally that our approach provides substantial performance benefits.

Physical Review A, 2014

We study the performance of composite pulses in the presence of time-varying control noise on a s... more We study the performance of composite pulses in the presence of time-varying control noise on a single qubit. These protocols, originally devised only to correct for static, systematic errors, are shown to be robust to time-dependent non-Markovian noise in the control field up to frequencies as high as ∼10% of the Rabi frequency. Our study combines a generalized filter-function approach with asymptotic dc-limit calculations to give a simple analytic framework for error analysis applied to a number of composite-pulse sequences relevant to nuclear magnetic resonance as well as quantum information experiments. Results include examination of recently introduced concatenated composite pulses and dynamically corrected gates, demonstrating equivalent first-order suppression of time-dependent fluctuations in amplitude and/or detuning, as appropriate for the sequence in question. Our analytic results agree well with numerical simulations for realistic 1/f noise spectra with a roll-off to 1/f 2 , providing independent validation of our theoretical insights.

ACM SIGMOD Record, 2008

Sharing structured data today requires standardizing upon a single schema, then mapping and clean... more Sharing structured data today requires standardizing upon a single schema, then mapping and cleaning all of the data. This results in a single queriable mediated data instance. However, for settings in which structured data is being collaboratively authored by a large community, e.g., in the sciences, there is often a lack of consensus about how it should be represented, what is correct, and which sources are authoritative. Moreover, such data is seldom static: it is frequently updated, cleaned, and annotated. The ORCHESTRA collaborative data sharing system develops a new architecture and consistency model for such settings, based on the needs of data sharing in the life sciences. In this paper we describe the basic architecture and implementation of the ORCHESTRA system, and summarize some of the open challenges that arise in this setting.

International Oil and Gas Conference and Exhibition in China, 2010

The increasing demand for horizontal production logs is driving the use of all possible well-inte... more The increasing demand for horizontal production logs is driving the use of all possible well-intervention technology approaches to fulfill technical diagnostic requirements and to acquire maximum logging coverage. Maximizing coverage will result in managing and exploiting the reservoir more efficiently. Coiled tubing (CT) is commonly used as an intervention tool for long openhole horizontal logging. As with any intervention tool, however, CT has operational limitations. Depending on the diameter of the openhole sections and the well trajectory, accessing laterals greater than 5,000 ft (1,524 m) is often problematic or not possible due to helical friction lock-up. Conventionally, we could change the geometry of the intervention (CT OD), utilize lubricants (metal/metal friction reducers) and more recently, use downhole tractors (well completion ID’s/OH OD’s might prevent some applications). The use of large–OD CT strings and lubricants have yielded 5-10% incremental reach in some case...

The VLDB Journal, 2007

Mapping composition is a fundamental operation in metadata driven applications. Given a mapping o... more Mapping composition is a fundamental operation in metadata driven applications. Given a mapping over schemas σ 1 and σ 2 and a mapping over schemas σ 2 and σ 3 , the composition problem is to compute an equivalent mapping over σ 1 and σ 3. We describe a new composition algorithm that targets practical applications. It incorporates view unfolding. It eliminates as many σ 2 symbols as possible, even if not all can be eliminated. It covers constraints expressed using arbitrary monotone relational operators and, to a lesser extent, non-monotone operators. And it introduces the new technique of left composition. We describe our implementation, explain how to extend it to support userdefined operators, and present experimental results which validate its effectiveness.

Physical Review Letters, 2012

Treating the effects of a time-dependent classical dephasing environment during quantum logic ope... more Treating the effects of a time-dependent classical dephasing environment during quantum logic operations poses a theoretical challenge, as the application of noncommuting control operations gives rise to both dephasing and depolarization errors that must be accounted for in order to understand total average error rates. We develop a treatment based on effective Hamiltonian theory that allows us to efficiently model the effect of classical noise on nontrivial single-bit quantum logic operations composed of arbitrary control sequences. We present a general method to calculate the ensemble-averaged entanglement fidelity to arbitrary order in terms of noise filter functions, and provide explicit expressions to fourth order in the noise strength. In the weak noise limit we derive explicit filter functions for a broad class of piecewise-constant control sequences, and use them to study the performance of dynamically corrected gates, yielding good agreement with brute-force numerics.

Nucleic Acids Research, 2013

All orthobunyaviruses possess three genome segments of single-stranded negative sense RNA that ar... more All orthobunyaviruses possess three genome segments of single-stranded negative sense RNA that are encapsidated with the virus-encoded nucleocapsid (N) protein to form a ribonucleoprotein (RNP) complex, which is uncharacterized at high resolution. We report the crystal structure of both the Bunyamwera virus (BUNV) N-RNA complex and the unbound Schmallenberg virus (SBV) N protein, at resolutions of 3.20 and 2.75 Å , respectively. Both N proteins crystallized as ring-like tetramers and exhibit a high degree of structural similarity despite classification into different orthobunyavirus serogroups. The structures represent a new RNAbinding protein fold. BUNV N possesses a positively charged groove into which RNA is deeply sequestered, with the bases facing away from the solvent. This location is highly inaccessible, implying that RNA polymerization and other critical base pairing events in the virus life cycle require RNP disassembly. Mutational analysis of N protein supports a correlation between structure and function. Comparison between these crystal structures and electron microscopy images of both soluble tetramers and authentic RNPs suggests the N protein does not bind RNA as a repeating monomer; thus, it represents a newly described architecture for bunyavirus RNP assembly, with implications for many other segmented negative-strand RNA viruses.

New Journal of Physics, 2013

We address the problem of deriving analytic expressions for calculating universal decoherence-ind... more We address the problem of deriving analytic expressions for calculating universal decoherence-induced errors in qubits undergoing arbitrary, unitary, timedependent quantum-control protocols. We show that the fidelity of a control operation may be expressed in terms of experimentally relevant spectral characteristics of the noise and of the control, over all Cartesian directions. We formulate control matrices in the time domain to capture the effects of piecewise-constant control, and convert them to generalized Fourier-domain filter functions. These generalized filter functions may be derived for complex temporally modulated control protocols, accounting for susceptibility to rotations of the qubit state vector in three dimensions. Taken together, we show that this framework provides a computationally efficient means to calculate the effects of universal noise on arbitrary quantum control protocols, producing results comparable to those obtained via time-consuming simulations of Bloch vector evolution. As a concrete example, we apply our method to treating the problem of dynamical decoupling incorporating realistic control pulses of arbitrary duration or form, including the replacement of simple π-pulses with complex dynamically corrected gates.

Nature Communications, 2013

Quantum memory is a central component for quantum information processing devices, and will be req... more Quantum memory is a central component for quantum information processing devices, and will be required to provide high-fidelity storage of arbitrary states, long storage times, and small access latencies. Despite growing interest in applying physical-layer error-suppression strategies to boost fidelities, it has not previously been possible to meet such competing demands with a single approach. Here, we use an experimentally validated theoretical framework to identify periodic repetition of a high-order dynamical decoupling sequence as a systematic strategy to meet these challenges. We provide analytic bounds-validated by numerical calculations-on the characteristics of the relevant control sequences and show that a "stroboscopic saturation" of coherence, or coherence plateau, can be engineered, even in the presence of experimental imperfection. This permits high-fidelity storage for times that can be exceptionally long, meaning that our device-independent results should prove instrumental in producing practically useful quantum technologies.

Journal of Allergy and Clinical Immunology, 2014