5,511 research outputs found
Event detection from click-through data via query clustering
The web is an index of real-world events and lot of knowledge can be mined from the web resources and their derivatives. Event detection is one recent research topic triggered from the domain of web data mining with the increasing popularity of search engines. In the visitor-centric approach, the click-through data generated by the web search engines is the start up resource with the intuition: often such data is event-driven. In this thesis, a retrospective algorithm is proposed to detect such real-world events from the click-through data. This approach differs from the existing work as it: (i) considers the click-through data as collaborative query sessions instead of mere web logs and try to understand user behavior (ii) tries to integrate the semantics, structure, and content of queries and pages (iii) aims to achieve the overall objective via Query Clustering. The problem of event detection is transformed into query clustering by generating clusters - hybrid cover graphs; each hybrid cover graph corresponds to a real-world event. The evolutionary pattern for the co-occurrences of query-page pairs in a hybrid cover graph is imposed for the quality purpose over a moving window period. Also, the approach is experimentally evaluated on a commercial search engine\u27s data collected over 3 months with about 20 million web queries and page clicks from 650000 users. The results outperform the most recent work in this domain in terms of number of events detected, F-measures, entropy, recall etc. --Abstract, page iv
Water filtration by using apple and banana peels as activated carbon
Water filter is an important devices for reducing the contaminants in raw water. Activated from charcoal is used to absorb the contaminants. Fruit peels are some of the suitable alternative carbon to substitute the charcoal. Determining the role of fruit peels which were apple and banana peels powder as activated carbon in water filter is the main goal. Drying and blending the peels till they become powder is the way to allow them to absorb the contaminants. Comparing the results for raw water before and after filtering is the observation. After filtering the raw water, the reading for pH was 6.8 which is in normal pH and turbidity reading recorded was 658 NTU. As for the colour, the water becomes more clear compared to the raw water. This study has found that fruit peels such as banana and apple are an effective substitute to charcoal as natural absorbent
Evolving Ensemble Fuzzy Classifier
The concept of ensemble learning offers a promising avenue in learning from
data streams under complex environments because it addresses the bias and
variance dilemma better than its single model counterpart and features a
reconfigurable structure, which is well suited to the given context. While
various extensions of ensemble learning for mining non-stationary data streams
can be found in the literature, most of them are crafted under a static base
classifier and revisits preceding samples in the sliding window for a
retraining step. This feature causes computationally prohibitive complexity and
is not flexible enough to cope with rapidly changing environments. Their
complexities are often demanding because it involves a large collection of
offline classifiers due to the absence of structural complexities reduction
mechanisms and lack of an online feature selection mechanism. A novel evolving
ensemble classifier, namely Parsimonious Ensemble pENsemble, is proposed in
this paper. pENsemble differs from existing architectures in the fact that it
is built upon an evolving classifier from data streams, termed Parsimonious
Classifier pClass. pENsemble is equipped by an ensemble pruning mechanism,
which estimates a localized generalization error of a base classifier. A
dynamic online feature selection scenario is integrated into the pENsemble.
This method allows for dynamic selection and deselection of input features on
the fly. pENsemble adopts a dynamic ensemble structure to output a final
classification decision where it features a novel drift detection scenario to
grow the ensemble structure. The efficacy of the pENsemble has been numerically
demonstrated through rigorous numerical studies with dynamic and evolving data
streams where it delivers the most encouraging performance in attaining a
tradeoff between accuracy and complexity.Comment: this paper has been published by IEEE Transactions on Fuzzy System
SMOTE for Learning from Imbalanced Data: Progress and Challenges, Marking the 15-year Anniversary
The Synthetic Minority Oversampling Technique (SMOTE) preprocessing algorithm is
considered \de facto" standard in the framework of learning from imbalanced data. This
is due to its simplicity in the design of the procedure, as well as its robustness when applied
to di erent type of problems. Since its publication in 2002, SMOTE has proven
successful in a variety of applications from several di erent domains. SMOTE has also inspired
several approaches to counter the issue of class imbalance, and has also signi cantly
contributed to new supervised learning paradigms, including multilabel classi cation, incremental
learning, semi-supervised learning, multi-instance learning, among others. It is
standard benchmark for learning from imbalanced data. It is also featured in a number of
di erent software packages | from open source to commercial. In this paper, marking the
fteen year anniversary of SMOTE, we re
ect on the SMOTE journey, discuss the current
state of a airs with SMOTE, its applications, and also identify the next set of challenges
to extend SMOTE for Big Data problems.This work have been partially supported by the Spanish Ministry of Science and Technology
under projects TIN2014-57251-P, TIN2015-68454-R and TIN2017-89517-P; the Project
887 BigDaP-TOOLS - Ayudas Fundaci on BBVA a Equipos de Investigaci on Cient ca 2016;
and the National Science Foundation (NSF) Grant IIS-1447795
BigFCM: Fast, Precise and Scalable FCM on Hadoop
Clustering plays an important role in mining big data both as a modeling
technique and a preprocessing step in many data mining process implementations.
Fuzzy clustering provides more flexibility than non-fuzzy methods by allowing
each data record to belong to more than one cluster to some degree. However, a
serious challenge in fuzzy clustering is the lack of scalability. Massive
datasets in emerging fields such as geosciences, biology and networking do
require parallel and distributed computations with high performance to solve
real-world problems. Although some clustering methods are already improved to
execute on big data platforms, but their execution time is highly increased for
large datasets. In this paper, a scalable Fuzzy C-Means (FCM) clustering named
BigFCM is proposed and designed for the Hadoop distributed data platform. Based
on the map-reduce programming model, it exploits several mechanisms including
an efficient caching design to achieve several orders of magnitude reduction in
execution time. Extensive evaluation over multi-gigabyte datasets shows that
BigFCM is scalable while it preserves the quality of clustering
New Archive-Based Ant Colony Optimization Algorithms for Learning Predictive Rules from Data
Data mining is the process of extracting knowledge and patterns from data. Classification and Regression are among the major data mining tasks, where the goal is to predict a value of an attribute of interest for each data instance, given the values of a set of predictive attributes. Most classification and regression problems involve continuous, ordinal and categorical attributes. Currently Ant Colony Optimization (ACO) algorithms have focused on directly handling categorical attributes only; continuous attributes are transformed using a discretisation procedure in either a preprocessing stage or dynamically during the rule creation. The use of a discretisation procedure has several limitations: (i) it increases the computational runtime, since several candidates values need to evaluated; (ii) requires access to the entire attribute domain, which in some applications all data is not available; (iii) the values used to create discrete intervals are not optimised in combination with the values of other attributes. This thesis investigates the use of solution archive pheromone model, based on Ant Colony Optimization for mixed-variable (ACOMV) algorithm, to directly cope with all attribute types. Firstly, an archive-based ACO classification algorithm is presented, followed by an automatic design framework to generate new configuration of ACO algorithms. Then, we addressed the challenging problem of mining data streams, presenting a new ACO algorithm in combination with a hybrid pheromone model. Finally, the archive-based approach is extended to cope with regression problems. All algorithms presented are compared against well-known algorithms from the literature using publicly available data sets. Our results have been shown to improve the computational time while maintaining a competitive predictive performance
A Comprehensive Survey of Data Mining-based Fraud Detection Research
This survey paper categorises, compares, and summarises from almost all
published technical and review articles in automated fraud detection within the
last 10 years. It defines the professional fraudster, formalises the main types
and subtypes of known fraud, and presents the nature of data evidence collected
within affected industries. Within the business context of mining the data to
achieve higher cost savings, this research presents methods and techniques
together with their problems. Compared to all related reviews on fraud
detection, this survey covers much more technical articles and is the only one,
to the best of our knowledge, which proposes alternative data and solutions
from related domains.Comment: 14 page
- …