Search results for "Database system"
showing 10 items of 56 documents
CASE tool support for co-operative work in information systems design
1998
The need for asynchronous co-operative work in design is shown by many surveys of CASE tool use and research on design. MetaEdit+ is a metaCASE environment that allows multiple simultaneous modellers to work together on designing information systems and also information systems design methods. We describe the automatic locking strategies that enable MetaEdit+ to offer a high level of concurrency whilst guaranteeing consistency, enabling effective co-operative work. In particular we describe a new collection data structure that allows high concurrency of updates even at small sizes, fulfilling the need in CASE for largest growth of design information at the start of a project. Finally, we ev…
Transparent Model for State Management
2013
To ensure optimum governance of the state (regions, sectors, specific activities) all management system units (tasks, functions and services, normative environment, institutional framework, budget funding) have to operate in strong cooperation and consistency, which should be defined by corresponding documents. Unfortunately this logical relevance does not always exist. Documents and information are weakly connected, because of the huge complexity of units that objectively hinders implementation of the strong linkage and seriously weakens management quality. The situation can be radically improved by usage of ontological methodology for development of the back-office of the management syste…
Improving Isolation of Blindly Separated Sources Using Time-Frequency Masking
2008
A refinement technique based on time-frequency masking is proposed to improve source isolation in blind audio source separation algorithms. The refinement technique uses an energy-normalized source-to-interference ratio in order to identify and eliminate interfering energy from the extracted sources. Some examples using this refinement method with different separation algorithms are discussed. The results show that source isolation can be significantly enhanced with negligible degradation of the separated sources.
Complementary Judgment Matrix Method with Imprecise Information for Multicriteria Decision-Making
2018
The complementary judgment matrix (CJM) method is an MCDA (multicriteria decision aiding) method based on pairwise comparisons. As in AHP, the decision-maker (DM) can specify his/her preferences using pairwise comparisons, both between different criteria and between different alternatives with respect to each criterion. The DM specifies his/her preferences by allocating two nonnegative comparison values so that their sum is 1. We measure and pinpoint possible inconsistency by inconsistency errors. We also compare the consistency of CJM and AHP trough simulation. Because preference judgments are always more or less imprecise or uncertain, we introduce a way to represent the uncertainty throu…
Simurgh
2021
The availability of non-volatile main memory (NVMM) has started a new era for storage systems and NVMM specific file systems can support extremely high data and metadata rates, which are required by many HPC and data-intensive applications. Scaling metadata performance within NVMM file systems is nevertheless often restricted by the Linux kernel storage stack, while simply moving metadata management to the user space can compromise security or flexibility. This paper introduces Simurgh, a hardware-assisted user space file system with decentralized metadata management that allows secure metadata updates from within user space. Simurgh guarantees consistency, durability, and ordering of updat…
About the Ghosh Model: Clarifications
2007
We examine the consistency of the Ghosh supply-d riven input-output model (SM) by respect to the traditional Leontief demand-drive n input-output model (LM); the variants considered are: primal and dual, quantity and value ; input prices are not considered. SM offers solutions of limited interest, being incapab le to separate quantities and prices or values and price indexes. Comparing the dual value SM to the primal of LM is wrong. Even if the agents are forced to buy inputs in SM, the interpre tation of SM as a centrally planned economy must be rejected but SM may serve for modeling interfirm relations or analyzing the structural interindustry change when the production function is not sp…
Verifying a medical protocol with temporal graphs: the case of a nosocomial disease.
2014
Abstract Objective Our contribution focuses on the implementation of a formal verification approach for medical protocols with graphical temporal reasoning paths to facilitate the understanding of verification steps. Materials and methods Formal medical guideline specifications and background knowledge are represented through conceptual graphs, and reasoning is based on graph homomorphism. These materials explain the underlying principles or rationale that guide the functioning of verifications. Results An illustration of this proposal is made using a medical protocol defining guidelines for the monitoring and prevention of nosocomial infections. Such infections, which are acquired in the h…
The analytic hierarchy process with stochastic judgements
2014
The analytic hierarchy process (AHP) is a widely-used method for multicriteria decision support based on the hierarchical decomposition of objectives, evaluation of preferences through pairwise comparisons, and a subsequent aggregation into global evaluations. The current paper integrates the AHP with stochastic multicriteria acceptability analysis (SMAA), an inverse-preference method, to allow the pairwise comparisons to be uncertain. A simulation experiment is used to assess how the consistency of judgements and the ability of the SMAA-AHP model to discern the best alternative deteriorates as uncertainty increases. Across a range of simulated problems results indicate that, according to c…
Consistency Analysis of Genome-Scale Models of Bacterial Metabolism: A Metamodel Approach.
2015
Genome-scale metabolic models usually contain inconsistencies that manifest as blocked reactions and gap metabolites. With the purpose to detect recurrent inconsistencies in metabolic models, a large-scale analysis was performed using a previously published dataset of 130 genome-scale models. The results showed that a large number of reactions (~22%) are blocked in all the models where they are present. To unravel the nature of such inconsistencies a metamodel was construed by joining the 130 models in a single network. This metamodel was manually curated using the unconnected modules approach, and then, it was used as a reference network to perform a gap-filling on each individual genome-s…
Physics-Aware Machine Learning For Geosciences And Remote Sensing
2021
Machine learning models alone are excellent approximators, but very often do not respect the most elementary laws of physics, like mass or energy conservation, so consistency and confidence are compromised. In this paper we describe the main challenges ahead in the field, and introduce several ways to live in the Physics and machine learning interplay: encoding differential equations from data, constraining data-driven models with physics-priors and dependence constraints, improving parameterizations, emulating physical models, and blending data-driven and process-based models. This is a collective long-term AI agenda towards developing and applying algorithms capable of discovering knowled…