Search results for "Data modeling"
showing 10 items of 112 documents
Consistent Regression of Biophysical Parameters with Kernel Methods
2020
This paper introduces a novel statistical regression framework that allows the incorporation of consistency constraints. A linear and nonlinear (kernel-based) formulation are introduced, and both imply closed-form analytical solutions. The models exploit all the information from a set of drivers while being maximally independent of a set of auxiliary, protected variables. We successfully illustrate the performance in the estimation of chlorophyll content.
Explainable Student Agency Analytics
2021
Several studies have shown that complex nonlinear learning analytics (LA) techniques outperform the traditional ones. However, the actual integration of these techniques in automatic LA systems remains rare because they are generally presumed to be opaque. At the same time, the current reviews on LA in higher education point out that LA should be more grounded to the learning science with actual linkage to teachers and pedagogical planning. In this study, we aim to address these two challenges. First, we discuss different techniques that open up the decision-making process of complex techniques and how they can be integrated in LA tools. More precisely, we present various global and local e…
Firefly optimization used to identify hysteresis parameter on rotational MR-damper
2014
In his paper the physical properties and mathematical models of a semi-active magnetorheological (MR) damper is studied. The considered models are the Dahl model and Bouc-Wen model. The parameters for these models are found by using a firefly optimization algorithm that minimizes the difference between experimental and simulated data. The objective of his paper is to compare different mathematical MR-damper models with the experimental data. The simulation results illustrate he effectiveness of he proposed optimization algorithm.
On Using Conceptual Modeling for Ontologies
2004
Are database concepts and techniques suitable for ontology design and management? The question has been on the floor for some time already. It gets a new emphasis today, thanks to the focus on ontologies and ontology services due to the spread of web services as a new paradigm for information management. This paper analyzes some of the arguments that are relevant to the debate, in particular the question whether conceptual data models would adequately support the design and use of ontologies. It concludes suggesting a hybrid approach, combining databases and logic-based services.
Multi-data models translations in interoperable information systems
1996
Interoperation of heterogeneous and autonomous information systems has traditionally been hampered by semantic differences in their data models. In this paper, we address the problem by defining a methodology called TIME, which is based on an extensible meta model. Its key features are: a set of meta-types which can be used to represent the syntax and the semantics of data modeling concepts, a knowledge base of transformation rules that map a meta-type into other meta-types, and an inference engine which uses the transformation rules to translate schema from source to target models. The extensibility of the meta-model is achieved by organizing the meta-types into a generalization hierarchy …
Model independent assertions for integration of heterogeneous schemas
1992
Due to the proliferation of database applications, the integration of existing databases into a distributed or federated system is one of the major challenges in responding to enterprises' information requirements. Some proposed integration techniques aim at providing database administrators (DBAs) with a view definition language they can use to build the desired integrated schema. These techniques leave to the DBA the responsibility of appropriately restructuring schema elements from existing local schemas and of solving inter-schema conflicts. This paper investigates the assertion-based approach, in which the DBA's action is limited to pointing out corresponding elements in the schemas an…
Design, Implementation, and Evaluation of a Virtual Meeting Tool-Based Innovation for UML Technology Training in Global Organizations
2012
End-user training is complicated to implement in global corporations whose activities are typically scattered across multiple sites in different countries and leverage information systems in various ways. This is especially true in global software development where the sites may leverage a development tool for totally different purposes. Web-based Virtual Meeting Tools (VMT) enable synchronous communication globally through interactive audio, online chats, video, and the sharing of presentations. They provide potentially a cost effective way to train even complex topics to large numbers of people in global settings. Few industrial experiences from the design and use of VMT-based training in…
XML Enabled Metamodeling and Tools for Cooperative Information Systems
2001
The development of tools to support semantic resolution is a key issue in the design of heterogeneous interoperable information systems. This paper presents a methodology and a data model translator toolkit, called X-TIME, for the design and management of interoperable information systems. X-TIME combines a metamodelling approach and XML features to provide support for automated design of wrappers or semantic reconciliators. It is a flexible semantics oriented approach that takes into account several important characteristics of interoperable information systems, including extensibility and composability. Extensibility requires a translation scheme that can easily integrate new data models.…
Matrix Shuffle- Exchange Networks for Hard 2D Tasks
2021
Convolutional neural networks have become the main tools for processing two-dimensional data. They work well for images, yet convolutions have a limited receptive field that prevents its applications to more complex 2D tasks. We propose a new neural model, called Matrix Shuffle-Exchange network, that can efficiently exploit long-range dependencies in 2D data and has comparable speed to a convolutional neural network. It is derived from Neural Shuffle-Exchange network and has O(log N) layers and O(N ^ 2 log N) total time and O(N^2) space complexity for processing a NxN data matrix. We show that the Matrix Shuffle-Exchange network is well-suited for algorithmic and logical reasoning tasks on …
Mobile radio channel models for present and future wireless communication systems
2008
From the beginnings of mobile communication, there is a high demand for realistic models for mobile fading channels. The reason for the demand is that channel models are essential for the performance evaluation, parameter optimisation, and test of mobile communication systems. Design methods for mobile fading channels are therefore of great importance for system engineers who are involved in the development of present and future mobile communication systems. In this presentation, an overview will be given about several design methodologies commonly used for the design of mobile radio channel models in present and future wireless communication systems. All presented channel models have in co…