Search results for "programming."
showing 10 items of 3035 documents
RDB2OWL
2010
RDB2OWL is a simple approach of mapping relational databases into independently developed OWL ontologies. The approach is based on creating a mapping RDB schema, filling it with mapping information from which SQL scripts are generated that perform the instance-level transformation. We describe the RDB2OWL mapping schema and report on successful application of the technology to the migration of Latvian medical registries data.
An Information Aggregation and Analytics System for ATLAS Frontier
2019
International audience; ATLAS event processing requires access to centralized database systems where information about calibrations, detector status and data-taking conditions are stored. This processing is done on more than 150 computing sites on a world-wide computing grid which are able to access the database using the Squid-Frontier system. Some processing workflows have been found which overload the Frontier system due to the Conditions data model currently in use, specifically because some of the Conditions data requests have been found to have a low caching efficiency. The underlying cause is that non-identical requests as far as the caching are actually retrieving a much smaller num…
Expressive and efficient pattern languages for tree-structured data (extended abstract)
2000
It would be desirable to have a query language for tree-structured data that is (1) as easily usable as SQL, (2) as expressive as monadic second-order logic (MSO), and (3) efficiently evaluable. The paper develops some ideas in this direction. Towards (1) the specification of sets of vertices of a tree by combining conditions on their induced subtree with conditions on their path to the root is proposed. Existing query languages allow regular expressions (hence MSO logic) in path conditions but are limited in expressing subtree conditions. It is shown that such query languages fall short of capturing all MSO queries. On the other hand, allowing a certain guarded fragment of MSO-logic in the…
An Approach to Data Quality Evaluation
2018
This research proposes a new approach to data quality evaluation comprising 3 aspects: (1) data object definition, which quality will be analyzed, (2) quality requirements specification for the data object using Domain Specific Language (DSL), (3) implementation of an executable data quality model that would enable scanning of data object and detect its shortages. Like the Model Driven Architecture (MDA) the data quality modelling is divided into platform independent (PIM) and platform-specific (PSM) models. PIM comprises informal specifications of data quality, PSM describes implementation of data quality model, thus making the data quality model executable. The approbation of the proposed…
Automatische Anästhesieprotokollsysteme
1997
The introduction of electronic anaesthesia documentation systems was attempted as early as in 1979, although their efficient application has become reality only in the past few years. The advantages of the electronic protocol are apparent: Continuous high quality documentation, comparability of data due to the availability of a data bank, reduction in the workload of the anaesthetist and availability of additional data. Disadvantages of the electronic protocol have also been discussed in the literature. By going through the process of entering data on the course of the anaesthetic procedure on the protocol sheet, the information is mentally absorbed and evaluated by the anaesthetist. This i…
The Effects of Database Complexity on SQL Query Formulation
2020
In Structured Query Language (SQL) education, students often execute queries against a simple exercise database. Recently, databases that are more realistic have been utilized to the effect that students find exercises more interesting and useful, as these databases more accurately mimic databases students are likely to encounter in their future work environments. However, using even the most engaging database can be counterproductive to learning, if a student is not able to formulate correct queries due to the complexity of the database schema. Scientific evidence on the effects of database complexity on student’s query formulation is limited, and with queries from 744 students against thr…
Large-scale genome-wide association studies on a GPU cluster using a CUDA-accelerated PGAS programming model
2015
[Abstract] Detecting epistasis, such as 2-SNP interactions, in genome-wide association studies (GWAS) is an important but time consuming operation. Consequently, GPUs have already been used to accelerate these studies, reducing the runtime for moderately-sized datasets to less than 1 hour. However, single-GPU approaches cannot perform large-scale GWAS in reasonable time. In this work we present multiEpistSearch, a tool to detect epistasis that works on GPU clusters. While CUDA is used for parallelization within each GPU, the workload distribution among GPUs is performed with Unified Parallel C++ (UPC++), a novel extension of C++ that follows the Partitioned Global Address Space (PGAS) model…
The mapping properties of the radiosity operator along an edge
2002
In this article we study the radiosity operator along an edge between two adjacent half-planes. First we show that the radiosity operator is invertible in a whole scale of anisotropic Sobolev spaces. In the absence of any shadows we are able to derive regularity properties of the solution, which depend only on the angle between the half-planes, the reflectivity coefficients and the right-hand side. This work can be considered as a supplement to the article of Rathsfeld (Mathematical Methods in the Applied Sciences 1999; 22: 217–241). Copyright © 2002 John Wiley & Sons, Ltd.
Checkpointing Workflows for Fail-Stop Errors
2017
International audience; We consider the problem of orchestrating the exe- cution of workflow applications structured as Directed Acyclic Graphs (DAGs) on parallel computing platforms that are subject to fail-stop failures. The objective is to minimize expected overall execution time, or makespan. A solution to this problem consists of a schedule of the workflow tasks on the available processors and of a decision of which application data to checkpoint to stable storage, so as to mitigate the impact of processor failures. For general DAGs this problem is hopelessly intractable. In fact, given a solution, computing its expected makespan is still a difficult problem. To address this challenge,…
Flexibility Services to Minimize the Electricity Production from Fossil Fuels. A Case Study in a Mediterranean Small Island
2019
The design of multi-carrier energy systems (MESs) has become increasingly important in the last decades, due to the need to move towards more efficient, flexible, and reliable power systems. In a MES, electricity, heating, cooling, water, and other resources interact at various levels, in order to get optimized operation. The aim of this study is to identify the optimal combination of components, their optimal sizes, and operating schedule allowing minimizing the annual cost for meeting the energy demand of Pantelleria, a Mediterranean island. Starting from the existing energy system (comprising diesel generators, desalination plant, freshwater storage, heat pumps, and domestic hot water st…