314 research outputs found
Framework for data quality in knowledge discovery tasks
Actualmente la explosión de datos es tendencia en el universo digital debido a los
avances en las tecnologÃas de la información. En este sentido, el descubrimiento
de conocimiento y la minerÃa de datos han ganado mayor importancia debido a
la gran cantidad de datos disponibles. Para un exitoso proceso de descubrimiento
de conocimiento, es necesario preparar los datos. Expertos afirman que la fase de
preprocesamiento de datos toma entre un 50% a 70% del tiempo de un proceso de
descubrimiento de conocimiento.
Herramientas software basadas en populares metodologÃas para el descubrimiento
de conocimiento ofrecen algoritmos para el preprocesamiento de los datos.
Según el cuadrante mágico de Gartner de 2018 para ciencia de datos y plataformas
de aprendizaje automático, KNIME, RapidMiner, SAS, Alteryx, y H20.ai son las
mejores herramientas para el desucrimiento del conocimiento. Estas herramientas
proporcionan diversas técnicas que facilitan la evaluación del conjunto de datos,
sin embargo carecen de un proceso orientado al usuario que permita abordar los
problemas en la calidad de datos. Adem´as, la selección de las técnicas adecuadas
para la limpieza de datos es un problema para usuarios inexpertos, ya que estos
no tienen claro cuales son los métodos más confiables.
De esta forma, la presente tesis doctoral se enfoca en abordar los problemas
antes mencionados mediante: (i) Un marco conceptual que ofrezca un proceso
guiado para abordar los problemas de calidad en los datos en tareas de descubrimiento
de conocimiento, (ii) un sistema de razonamiento basado en casos
que recomiende los algoritmos adecuados para la limpieza de datos y (iii) una ontologÃa que representa el conocimiento de los problemas de calidad en los datos
y los algoritmos de limpieza de datos. Adicionalmente, esta ontologÃa contribuye
en la representacion formal de los casos y en la fase de adaptación, del sistema de
razonamiento basado en casos.The creation and consumption of data continue to grow by leaps and bounds. Due
to advances in Information and Communication Technologies (ICT), today the
data explosion in the digital universe is a new trend. The Knowledge Discovery
in Databases (KDD) gain importance due the abundance of data. For a successful
process of knowledge discovery is necessary to make a data treatment. The
experts affirm that preprocessing phase take the 50% to 70% of the total time of
knowledge discovery process.
Software tools based on Knowledge Discovery Methodologies offers algorithms
for data preprocessing. According to Gartner 2018 Magic Quadrant for
Data Science and Machine Learning Platforms, KNIME, RapidMiner, SAS, Alteryx
and H20.ai are the leader tools for knowledge discovery. These software
tools provide different techniques and they facilitate the evaluation of data analysis,
however, these software tools lack any kind of guidance as to which techniques
can or should be used in which contexts. Consequently, the use of suitable data
cleaning techniques is a headache for inexpert users. They have no idea which
methods can be confidently used and often resort to trial and error.
This thesis presents three contributions to address the mentioned problems:
(i) A conceptual framework to provide the user a guidance to address data quality
issues in knowledge discovery tasks, (ii) a Case-based reasoning system to
recommend the suitable algorithms for data cleaning, and (iii) an Ontology that
represent the knowledge in data quality issues and data cleaning methods. Also,
this ontology supports the case-based reasoning system for case representation
and reuse phase.Programa Oficial de Doctorado en Ciencia y TecnologÃa InformáticaPresidente: Fernando Fernández Rebollo.- Secretario: Gustavo Adolfo RamÃrez.- Vocal: Juan Pedro Caraça-Valente Hernánde
A case-based reasoning system for recommendation of data cleaning algorithms in classification and regression tasks
Recently, advances in Information Technologies (social networks, mobile applications, Internet of Things, etc.) generate a deluge of digital data; but to convert these data into useful information for business decisions is a growing challenge. Exploiting the massive amount of data through knowledge discovery (KD) process includes identifying valid, novel, potentially useful and understandable patterns from a huge volume of data. However, to prepare the data is a non-trivial refinement task that requires technical expertise in methods and algorithms for data cleaning. Consequently, the use of a suitable data analysis technique is a headache for inexpert users. To address these problems, we propose a case-based reasoning system (CBR) to recommend data cleaning algorithms for classification and regression tasks. In our approach, we represent the problem space by the meta-features of the dataset, its attributes, and the target variable. The solution space contains the algorithms of data cleaning used for each dataset. We represent the cases through a Data Cleaning Ontology. The case retrieval mechanism is composed of a filter and similarity phases. In the first phase, we defined two filter approaches based on clustering and quartile analysis. These filters retrieve a reduced number of relevant cases. The second phase computes a ranking of the retrieved cases by filter approaches, and it scores a similarity between a new case and the retrieved cases. The retrieval mechanism proposed was evaluated through a set of judges. The panel of judges scores the similarity between a query case against all cases of the case-base (ground truth). The results of the retrieval mechanism reach an average precision on judges ranking of 94.5% in top 3, for top 7 84.55%, while in top 10 78.35%.The authors are grateful to the research groups: Control Learning Systems Optimization Group (CAOS) of the Carlos III University of Madrid and Telematics Engineering Group (GIT) of the University of Cauca for the technical support. In addition, the authors are grateful to COLCIENCIAS for PhD scholarship granted to PhD. David Camilo Corrales. This work has been also supported by: Project Alternativas Innovadoras de Agricultura Inteligente para sistemas productivos agrÃcolas del departamento del Cauca soportado en entornos de IoT financed by Convocatoria 04C-2018 Banco de Proyectos Conjuntos UEES-Sostenibilidad of Project Red de formación de talento humano para la innovación social y productiva en el Departamento del Cauca InnovAcción Cauca, ID-3848. The Spanish Ministry of Economy, Industry and Competitiveness (Projects TRA2015-63708-R and TRA2016-78886-C3-1-R)
Algorithm selection using edge ML and case-based reasoning
In practical data mining, a wide range of classification algorithms is employed for prediction tasks. However, selecting the best algorithm poses a challenging task for machine learning practitioners and experts, primarily due to the inherent variability in the characteristics of classification problems, referred to as datasets, and the unpredictable performance of these algorithms. Dataset characteristics are quantified in terms of meta-features, while classifier performance is evaluated using various performance metrics. The assessment of classifiers through empirical methods across multiple classification datasets, while considering multiple performance metrics, presents a computationally expensive and time-consuming obstacle in the pursuit of selecting the optimal algorithm. Furthermore, the scarcity of sufficient training data, denoted by dimensions representing the number of datasets and the feature space described by meta-feature perspectives, adds further complexity to the process of algorithm selection using classical machine learning methods. This research paper presents an integrated framework called eML-CBR that combines edge edge-ML and case-based reasoning methodologies to accurately address the algorithm selection problem. It adapts a multi-level, multi-view case-based reasoning methodology, considering data from diverse feature dimensions and the algorithms from multiple performance aspects, that distributes computations to both cloud edges and centralized nodes. On the edge, the first-level reasoning employs machine learning methods to recommend a family of classification algorithms, while at the second level, it recommends a list of the top-k algorithms within that family. This list is further refined by an algorithm conflict resolver module. The eML-CBR framework offers a suite of contributions, including integrated algorithm selection, multi-view meta-feature extraction, innovative performance criteria, improved algorithm recommendation, data scarcity mitigation through incremental learning, and an open-source CBR module, reshaping research paradigms. The CBR module, trained on 100 datasets and tested with 52 datasets using 9 decision tree algorithms, achieved an accuracy of 94% for correct classifier recommendations within the top k=3 algorithms, making it highly suitable for practical classification applications
CBR and MBR techniques: review for an application in the emergencies domain
The purpose of this document is to provide an in-depth analysis of current reasoning engine practice and the integration strategies of Case Based Reasoning and Model Based Reasoning that will be used in the design and development of the RIMSAT system.
RIMSAT (Remote Intelligent Management Support and Training) is a European Commission funded project designed to:
a.. Provide an innovative, 'intelligent', knowledge based solution aimed at improving the quality of critical decisions
b.. Enhance the competencies and responsiveness of individuals and organisations involved in highly complex, safety critical incidents - irrespective of their location.
In other words, RIMSAT aims to design and implement a decision support system that using Case Base Reasoning as well as Model Base Reasoning technology is applied in the management of emergency situations.
This document is part of a deliverable for RIMSAT project, and although it has been done in close contact with the requirements of the project, it provides an overview wide enough for providing a state of the art in integration strategies between CBR and MBR technologies.Postprint (published version
Introspective knowledge acquisition for case retrieval networks in textual case base reasoning.
Textual Case Based Reasoning (TCBR) aims at effective reuse of information contained in unstructured documents. The key advantage of TCBR over traditional Information Retrieval systems is its ability to incorporate domain-specific knowledge to facilitate case comparison beyond simple keyword matching. However, substantial human intervention is needed to acquire and transform this knowledge into a form suitable for a TCBR system. In this research, we present automated approaches that exploit statistical properties of document collections to alleviate this knowledge acquisition bottleneck. We focus on two important knowledge containers: relevance knowledge, which shows relatedness of features to cases, and similarity knowledge, which captures the relatedness of features to each other. The terminology is derived from the Case Retrieval Network (CRN) retrieval architecture in TCBR, which is used as the underlying formalism in this thesis applied to text classification. Latent Semantic Indexing (LSI) generated concepts are a useful resource for relevance knowledge acquisition for CRNs. This thesis introduces a supervised LSI technique called sprinkling that exploits class knowledge to bias LSI's concept generation. An extension of this idea, called Adaptive Sprinkling has been proposed to handle inter-class relationships in complex domains like hierarchical (e.g. Yahoo directory) and ordinal (e.g. product ranking) classification tasks. Experimental evaluation results show the superiority of CRNs created with sprinkling and AS, not only over LSI on its own, but also over state-of-the-art classifiers like Support Vector Machines (SVM). Current statistical approaches based on feature co-occurrences can be utilized to mine similarity knowledge for CRNs. However, related words often do not co-occur in the same document, though they co-occur with similar words. We introduce an algorithm to efficiently mine such indirect associations, called higher order associations. Empirical results show that CRNs created with the acquired similarity knowledge outperform both LSI and SVM. Incorporating acquired knowledge into the CRN transforms it into a densely connected network. While improving retrieval effectiveness, this has the unintended effect of slowing down retrieval. We propose a novel retrieval formalism called the Fast Case Retrieval Network (FCRN) which eliminates redundant run-time computations to improve retrieval speed. Experimental results show FCRN's ability to scale up over high dimensional textual casebases. Finally, we investigate novel ways of visualizing and estimating complexity of textual casebases that can help explain performance differences across casebases. Visualization provides a qualitative insight into the casebase, while complexity is a quantitative measure that characterizes classification or retrieval hardness intrinsic to a dataset. We study correlations of experimental results from the proposed approaches against complexity measures over diverse casebases
Knowledge Extraction and Summarization for Textual Case-Based Reasoning: A Probabilistic Task Content Modeling Approach
Case-Based Reasoning (CBR) is an Artificial Intelligence (AI) technique that
has been successfully used for building knowledge systems for tasks/domains where different knowledge sources are easily available, particularly in the form of problem solving situations, known as cases. Cases generally display a clear
distinction between different components of problem solving, for instance, components of the problem description and of the problem solution. Thus, an existing and explicit structure of cases is presumed. However, when problem solving experiences are stored in the form of textual narratives (in natural language), there is no explicit case structure, so that CBR cannot be applied directly.
This thesis presents a novel approach for authoring cases from episodic textual
narratives and organizing these cases in a case base structure that permits a
better support for user goals. The approach is based on the following fundamental ideas:
- CBR as a problem solving technique is goal-oriented and goals are realized by
means of task strategies.
- Tasks have an internal structure that can be represented in terms of
participating events and event components.
- Episodic textual narratives are not random containers of domain concept
terms. Rather, the text can be considered as generated by the underlying
task structure whose content they describe.
The presented case base authoring process combines task knowledge with Natural
Language Processing (NLP) techniques to perform the needed knowledge extraction
and summarization
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