474 research outputs found
Joint Verification and Reranking for Open Fact Checking Over Tables
Structured information is an important knowledge source for automatic verification of factual claims. Nevertheless, the majority of existing research into this task has focused on textual data, and the few recent inquiries into structured data have been for the closed-domain setting where appropriate evidence for each claim is assumed to have already been retrieved. In this paper, we investigate verification over structured data in the open-domain setting, introducing a joint reranking-and-verification model which fuses evidence documents in the verification component. Our open-domain model achieves performance comparable to the closed-domain state-of-the-art on the TabFact dataset, and demonstrates performance gains from the inclusion of multiple tables as well as a significant improvement over a heuristic retrieval baseline
Hydroblack 91 : report of the CTD Intercalibration Workshop
An Intercalibration Workshop was held at the Woods Hole Oceanographic Institution
(W.H.O.I.) from 1-10 December, 1991, for the CTD data acquired during HYDROBLACK '91.
This intercalibration exercise was a prelude to an interdisciplinary HYDROBLACK '91
intercalibration to be held in Crimea, Ukraine, in February, 1992, incorporating the full suite of physical, biological, and chemical measurements acquired during the cruise.
HYDROBLACK '91 acquired for the first time a complete hydrographic, biological, and
chemical data set for the entire Black Sea, to 200 m water depth, with the participation of all Black
Sea riparian countres as well as the U.S. Nearly 300 hydrographic stations were occupied to full
water depth; biological and chemical measurements were made at 100 of these stations. This
quasi-synoptic survey was accomplished using five ships during an interval of approximately three
weeks.
Results show some disparities between CTD's from the different regions, but the
intercalibrated results show a consistent and high resolution detail of the dynamic topography and
other physical characteristics of the entire Black Sea basin. The intercalibrated data set is now
available within each country and from W.H.O.I., and will form the basis for studies on ocean
physics as well as interdisciplinary issues such as oxygen depletion within the basin and hydrogen
sulfide distribution. This effort provides an intercalibrated, spatially-dense baseline against which
all future and past measurements can be compared.
In spite of significant economic pressures arising from the changes in the eastern European
countries, and the inadequate scientific exchange with the west during the past two decades,
HYDROBLACK '91 is considered a success and a model for future international scientific and
monitoring efforts thoughout the Black Sea. Similar efforts are anticipated twice-yearly in the
framework of the new Cooperative Marine Science Program for the Black Sea.Funding was provided by the National Science Foundation through Grant No. OCE-9121788, the
Vetleson Foundation, the Andrew W. Mellon Foundation, the Mobil Foundation, Inc. and the
Regional Environmental Center for Central & Eastern Europe (Budapest)
Black Sea coastal forecasting system
The Black Sea coastal nowcasting and forecasting system was built within the framework of EU FP6 ECOOP (European COastalshelf sea OPerational observing and forecasting system) project for five regions: the south-western basin along the coasts of Bulgaria and Turkey, the north-western shelf along the Romanian and Ukrainian coasts, coastal zone around of the Crimea peninsula, the north-eastern Russian coastal zone and the coastal zone of Georgia. The system operates in the real-time mode during the ECOOP project and afterwards. The forecasts include temperature, salinity and current velocity fields. Ecosystem model operates in the off-line mode near the Crimea coast
The Texas Library Directory Database: A Multipurpose Database for the Library of Texas
The paper presents an overview of the Texas Library Directory Database development effort. The TLDD was designed and implemented by the Texas Center for Digital Knowledge at the University of North Texas team as part of a project for the Texas State Library and Archives Commission to support the Library of Texas Resource Discovery Service. The TLDD offers a unique centralized controlled environment to collect a wide range of information about Texas libraries, to manage these data, and to offer a common repository of current information about Texas libraries for use by various TSLAC divisions, members of the Texas library community and library users. The paper examines issues that shaped the development of the TLDD, such as an international standard for directories of libraries, archives, information and documentation centre, and their databases (ISO2146); selection of the open source technical platform for the database and interface applications development; availability and quality of the data sources available to populate the database, etc. Challenges encountered during the project and suggestions for future library directory database development efforts are described
Domain-matched Pre-training Tasks for Dense Retrieval
Pre-training on larger datasets with ever increasing model size is now a proven recipe for increased performance across almost all NLP tasks. A notable exception is information retrieval, where additional pre-training has so far failed to produce convincing results. We show that, with the right pre-training setup, this barrier can be overcome. We demonstrate this by pre-training large bi-encoder models on 1) a recently released set of 65 million synthetically generated questions, and 2) 200 million post-comment pairs from a preexisting dataset of Reddit conversations. We evaluate on a set of information retrieval and dialogue retrieval benchmarks, showing substantial improvements over supervised baselines
Nonlinear modeling of an immersed transmitting capacitive micromachined ultrasonic transducer for harmonic balance analysis.
Finite element method (FEM) is used for transient dynamic analysis of capacitive micromachined ultrasonic transducers (CMUT) and is particularly useful when the membranes are driven in the nonlinear regime. One major disadvantage of FEM is the excessive time required for simulation. Harmonic balance (HB) analysis, on the other hand, provides an accurate estimate of the steady-state response of nonlinear circuits very quickly. It is common to use Mason's equivalent circuit to model the mechanical section of CMUT. However, it is not appropriate to terminate Mason's mechanical LC section by a rigid piston's radiation impedance, especially for an immersed CMUT. We studied the membrane behavior using a transient FEM analysis and found out that for a wide range of harmonics around the series resonance, the membrane displacement can be modeled as a clamped radiator. We considered the root mean square of the velocity distribution on the membrane surface as the circuit variable rather than the average velocity. With this definition, the kinetic energy of the membrane mass is the same as that in the model. We derived the force and current equations for a clamped radiator and implemented them using a commercial HB simulator. We observed much better agreement between FEM and the proposed equivalent model, compared with the conventional model
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Machine Learning to Identify Dialysis Patients at High Death Risk.
IntroductionGiven the high mortality rate within the first year of dialysis initiation, an accurate estimation of postdialysis mortality could help patients and clinicians in decision making about initiation of dialysis. We aimed to use machine learning (ML) by incorporating complex information from electronic health records to predict patients at risk for postdialysis short-term mortality.MethodsThis study was carried out on a contemporary cohort of 27,615 US veterans with incident end-stage renal disease (ESRD). We implemented a random forest method on 49 variables obtained before dialysis transition to predict outcomes of 30-, 90-, 180-, and 365-day all-cause mortality after dialysis initiation.ResultsThe mean (Ā±SD) age of our cohort was 68.7 Ā± 11.2 years, 98.1% of patients were men, 29.4% were African American, and 71.4% were diabetic. The final random forest model provided C-statistics (95% confidence intervals) of 0.7185 (0.6994-0.7377), 0.7446 (0.7346-0.7546), 0.7504 (0.7425-0.7583), and 0.7488 (0.7421-0.7554) for predicting risk of death within the 4 different time windows. The models showed good internal validity and replicated well in patients with various demographic and clinical characteristics and provided similar or better performance compared with other ML algorithms. Results may not be generalizable to non-veterans. Use of predictors available in electronic medical records has limited the assessment of number of predictors.ConclusionWe implemented and ML-based method to accurately predict short-term postdialysis mortality in patients with incident ESRD. Our models could aid patients and clinicians in better decision making about the best course of action in patients approaching ESRD
A three-dimensional coupled model of the western Black Sea plankton dynamics: Seasonal variability and comparison to SeaWiFS data
The main physical and biological processes that control the seasonal cycle of the plankton dynamics over the Western Black Sea were explored by means of a threeādimensional, 7ācompartment, onāline coupled biophysical model that was developed for this study. Adopting high frequency forcing in terms of airāsea interaction and Danube river inputs, we performed a simulation of the coupled model during the 2002ā2003 period. A series of 8āday Chlāa SeaWiFS images provided a validation tool that guided us, along with available in situ measurements, to the improvement of model parameterizations and the calibration of the biological parameters. The simulation of the seasonal phytoplankton variability over the entire Western Black Sea, extending from the highly eutrophic river influenced area to the open sea area, was a major challenge that made necessary the representation of both the spatial and time variability of several processes. Despite the model simplicity, the simulated Chlāa patterns presented a good agreement as compared to the SeaWiFS and in situ data. During winter, phytoplankton in coastal areas was shown to be limited by light availability, primarily due to the increased particulate matter concentrations, as a result of resuspension from the sediment and the increased river loads. During summer, the primary production was mostly sustained by riverine nutrients and regeneration processes and thus was strongly linked to the evolution of the Danube plume. The limiting nutrients showed deviations from the observed concentrations, indicating the necessity for a more realistic phytoplankton growth model
Improving emerging European NMIsā capabilities in humidity measurement
The control and measurement of humidity is important for many industrial
applications and to ensure the appropriate storage of materials and products. Humidity
measurement techniques are diverse and each presents different challenges for use and
calibration for a range of pressures and gases. Over the past few years, the development of
humidity sensors and apparatus has matured to a level where traceable calibration is beneficial
to all industries in which humidity and moisture measurement and control are important. This
paper deals with a European project in which the overall objective is to develop or extend the
measurement and research capabilities of the participating emerging NMI/DIsā countries in the
field of humidity measurements, where access to these types of facilities is currently limited
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