An Ontology Based Framework for Intelligent Web Based e-Learning

2015 ◽  
Vol 11 (2) ◽  
pp. 23-39 ◽  
Author(s):  
B. Senthilnayaki ◽  
K. Venkatalakshmi ◽  
A. Kannan
Keyword(s):  
Learning Style ◽  
Real World ◽  
Large Scale ◽  
Clustering Algorithm ◽  
Clustering Algorithms ◽  
Learning Performance ◽  
World Knowledge ◽  
E Learning ◽  
Domain Ontologies ◽  
Discovery Method

E-Learning is a fast, just-in-time, and non-linear learning process, which is now widely applied in distributed and dynamic environments such as the World Wide Web. Ontology plays an important role in capturing and disseminating the real world knowledge for effective human computer interactions. However, engineering of domain ontologies is very labor intensive and time consuming. Some machine learning methods have been explored for automatic or semi-automatic discovery of domain ontologies. Nevertheless, both the accuracy and the computational efficiency of these methods need to be improved. While constructing large scale ontology for real-world applications such as e-learning, the ability to monitor the progress of students' learning performance is a critical issue. In this paper, a system is proposed for analyzing students' knowledge level obtained using Kolb's classification based on the students level of understanding and their learning style using cluster analysis. This system uses fuzzy logic and clustering algorithms to arrange their documents according to the level of their performance. Moreover, a new domain ontology discovery method is proposed uses contextual information of the knowledge sources from the e-Learning domain. This proposed system constructs ontology to provide an effective assistance in e-Learning. The proposed ontology discovery method has been empirically tested in an e-Learning environment for teaching the subject Database Management Systems. The salient contributions of this paper are the use of Jaccard Similarity measure and K-Means clustering algorithm for clustering of learners and the use of ontology for concept understanding and learning style identification. This helps in adaptive e-learning by providing suitable suggestions for decision making and it uses decision rules for providing intelligent e-Learning.

Research on Parallel DBSCAN Algorithm Design Based on MapReduce

2011 ◽  
Vol 301-303 ◽  
pp. 1133-1138 ◽  
Author(s):  
Yan Xiang Fu ◽  
Wei Zhong Zhao ◽  
Hui Fang Ma
Keyword(s):  
Data Clustering ◽  
Large Scale ◽  
Clustering Algorithm ◽  
Clustering Algorithms ◽  
Algorithm Design ◽  
Document Retrieval ◽  
Commodity Hardware ◽  
Dbscan Clustering ◽  
Dbscan Algorithm ◽  
Parallel Clustering

Data clustering has been received considerable attention in many applications, such as data mining, document retrieval, image segmentation and pattern classification. The enlarging volumes of information emerging by the progress of technology, makes clustering of very large scale of data a challenging task. In order to deal with the problem, more researchers try to design efficient parallel clustering algorithms. In this paper, we propose a parallel DBSCAN clustering algorithm based on Hadoop, which is a simple yet powerful parallel programming platform. The experimental results demonstrate that the proposed algorithm can scale well and efficiently process large datasets on commodity hardware.

scholarly journals Efficient exploratory clustering analyses in large-scale exploration processes

2021 ◽  
Author(s):  
Manuel Fritz ◽  
Michael Behringer ◽  
Dennis Tschechlov ◽  
Holger Schwarz
Keyword(s):  
Large Scale ◽  
Clustering Algorithm ◽  
Comprehensive Evaluation ◽  
State Of The Art ◽  
Clustering Algorithms ◽  
Search Space ◽  
Large Datasets ◽  
Search Spaces ◽  
Multiple Challenges ◽  
The One

AbstractClustering is a fundamental primitive in manifold applications. In order to achieve valuable results in exploratory clustering analyses, parameters of the clustering algorithm have to be set appropriately, which is a tremendous pitfall. We observe multiple challenges for large-scale exploration processes. On the one hand, they require specific methods to efficiently explore large parameter search spaces. On the other hand, they often exhibit large runtimes, in particular when large datasets are analyzed using clustering algorithms with super-polynomial runtimes, which repeatedly need to be executed within exploratory clustering analyses. We address these challenges as follows: First, we present LOG-Means and show that it provides estimates for the number of clusters in sublinear time regarding the defined search space, i.e., provably requiring less executions of a clustering algorithm than existing methods. Second, we demonstrate how to exploit fundamental characteristics of exploratory clustering analyses in order to significantly accelerate the (repetitive) execution of clustering algorithms on large datasets. Third, we show how these challenges can be tackled at the same time. To the best of our knowledge, this is the first work which simultaneously addresses the above-mentioned challenges. In our comprehensive evaluation, we unveil that our proposed methods significantly outperform state-of-the-art methods, thus especially supporting novice analysts for exploratory clustering analyses in large-scale exploration processes.

MR-BIRCH: A scalable MapReduce-based birch clustering algorithm

2020 ◽  
pp. 1-11
Author(s):  
Yufeng Li ◽  
HaiTian Jiang ◽  
Jiyong Lu ◽  
Xiaozhong Li ◽  
Zhiwei Sun ◽  
...  
Keyword(s):  
Big Data ◽  
Real World ◽  
Clustering Algorithm ◽  
Clustering Algorithms ◽  
Statistical Information ◽  
Main Memory ◽  
Acceptable Result ◽  
Clustering Quality ◽  
Synthetic Datasets

Many classical clustering algorithms have been fitted into MapReduce, which provides a novel solution for clustering big data. However, several iterations are required to reach an acceptable result in most of the algorithms. For each iteration, a new MapReduce job must be executed to load the dataset into main memory, which results in high I/O overhead and poor efficiency. BIRCH algorithm stores only the statistical information of objects with CF entries and CF tree to cluster big data, but with the increase of the tree nodes, the main memory will be insufficient to contain more objects. Hence, BIRCH has to reduce the tree, which will degrade the clustering quality and decelerate the whole execution efficiency. To deal with the problem, BIRCH was fitted into MapReduce called MR-BIRCH in this paper. In contrast to a great number of MapReduce-based algorithms, MR-BIRCH loads dataset only once, and the dataset is processed parallel in several machines. The complexity and scalability were analyzed to evaluate the quality of MR-BIRCH, and MR-BIRCH was compared with Python sklearn BIRCH and Apache Mahout k-means on real-world and synthetic datasets. Experimental results show, most of the time, MR-BIRCH was better or equal to sklearn BIRCH, and it was competitive to Mahout k-means.

scholarly journals Analysis of University Students’ Behavior Based on a Fusion K-Means Clustering Algorithm

2020 ◽  
Vol 10 (18) ◽  
pp. 6566
Author(s):  
Wenbing Chang ◽  
Xinpeng Ji ◽  
Yinglai Liu ◽  
Yiyong Xiao ◽  
Bang Chen ◽  
...  
Keyword(s):  
Data Mining ◽  
Large Scale ◽  
Clustering Algorithm ◽  
Learning Performance ◽  
Practical Significance ◽  
Digital Campus ◽  
Data Mining Algorithms ◽  
Density Peaks ◽  
Data Points ◽  
The University

With the development of big data technology, creating the ‘Digital Campus’ is a hot issue. For an increasing amount of data, traditional data mining algorithms are not suitable. The clustering algorithm is becoming more and more important in the field of data mining, but the traditional clustering algorithm does not take the clustering efficiency and clustering effect into consideration. In this paper, the algorithm based on K-Means and clustering by fast search and find of density peaks (K-CFSFDP) is proposed, which improves on the distance and density of data points. This method is used to cluster students from four universities. The experiment shows that K-CFSFDP algorithm has better clustering results and running efficiency than the traditional K-Means clustering algorithm, and it performs well in large scale campus data. Additionally, the results of the cluster analysis show that the students of different categories in four universities had different performances in living habits and learning performance, so the university can learn about the students’ behavior of different categories and provide corresponding personalized services, which have certain practical significance.

Metagenome sequence clustering with hash-based canopies

2017 ◽  
Vol 15 (06) ◽  
pp. 1740006 ◽  
Author(s):  
Mohammad Arifur Rahman ◽  
Nathan LaPierre ◽  
Huzefa Rangwala ◽  
Daniel Barbara
Keyword(s):  
Large Scale ◽  
Clustering Algorithm ◽  
State Of The Art ◽  
Sequence Data ◽  
Clustering Algorithms ◽  
Clustering Methods ◽  
Operational Taxonomic Units ◽  
Sequence Clustering ◽  
Scalable Clustering ◽  
Metagenome Sequence

Metagenomics is the collective sequencing of co-existing microbial communities which are ubiquitous across various clinical and ecological environments. Due to the large volume and random short sequences (reads) obtained from community sequences, analysis of diversity, abundance and functions of different organisms within these communities are challenging tasks. We present a fast and scalable clustering algorithm for analyzing large-scale metagenome sequence data. Our approach achieves efficiency by partitioning the large number of sequence reads into groups (called canopies) using hashing. These canopies are then refined by using state-of-the-art sequence clustering algorithms. This canopy-clustering (CC) algorithm can be used as a pre-processing phase for computationally expensive clustering algorithms. We use and compare three hashing schemes for canopy construction with five popular and state-of-the-art sequence clustering methods. We evaluate our clustering algorithm on synthetic and real-world 16S and whole metagenome benchmarks. We demonstrate the ability of our proposed approach to determine meaningful Operational Taxonomic Units (OTU) and observe significant speedup with regards to run time when compared to different clustering algorithms. We also make our source code publicly available on Github. a

scholarly journals Parallel Implementation of Improved K-Means Based on a Cloud Platform

2019 ◽  
Vol 48 (4) ◽  
pp. 673-681
Author(s):  
Shufen Zhang ◽  
Zhiyu Liu ◽  
Xuebin Chen ◽  
Changyin Luo
Keyword(s):  
Large Scale ◽  
Clustering Algorithm ◽  
Programming Model ◽  
Parallel Implementation ◽  
Clustering Algorithms ◽  
Data Set ◽  
Large Scale Data ◽  
Sample Density ◽  
Scale Data ◽  
Selection Of

In order to solve the problem of traditional K-Means clustering algorithm in dealing with large-scale data set, a Hadoop K-Means (referred to HKM) clustering algorithm is proposed. Firstly, according to the sample density, the algorithm eliminates the effects of noise points in the data set. Secondly, it optimizes the selection of the initial center point using the thought of the max-min distance. Finally, it uses a MapReduce programming model to realize the parallelization. Experimental results show that the proposed algorithm not only has high accuracy and stability in clustering results, but can also solve the problems of scalability encountered by traditional clustering algorithms in dealing with large scale data.

scholarly journals Exploratory Item Classification Via Spectral Graph Clustering

2017 ◽  
Vol 41 (8) ◽  
pp. 579-599 ◽  
Author(s):  
Yunxiao Chen ◽  
Xiaoou Li ◽  
Jingchen Liu ◽  
Gongjun Xu ◽  
Zhiliang Ying
Keyword(s):  
Cluster Analysis ◽  
Spectral Clustering ◽  
Large Scale ◽  
Clustering Algorithm ◽  
Latent Class ◽  
Clustering Algorithms ◽  
Eysenck Personality Questionnaire ◽  
Computationally Efficient ◽  
Computational Overhead ◽  
Spectral Clustering Algorithm

Large-scale assessments are supported by a large item pool. An important task in test development is to assign items into scales that measure different characteristics of individuals, and a popular approach is cluster analysis of items. Classical methods in cluster analysis, such as the hierarchical clustering, K-means method, and latent-class analysis, often induce a high computational overhead and have difficulty handling missing data, especially in the presence of high-dimensional responses. In this article, the authors propose a spectral clustering algorithm for exploratory item cluster analysis. The method is computationally efficient, effective for data with missing or incomplete responses, easy to implement, and often outperforms traditional clustering algorithms in the context of high dimensionality. The spectral clustering algorithm is based on graph theory, a branch of mathematics that studies the properties of graphs. The algorithm first constructs a graph of items, characterizing the similarity structure among items. It then extracts item clusters based on the graphical structure, grouping similar items together. The proposed method is evaluated through simulations and an application to the revised Eysenck Personality Questionnaire.

Clustering Categorical Data with k-Modes

2011 ◽  
pp. 246-250 ◽  
Author(s):  
Joshua Zhexue Huang
Keyword(s):  
Real World ◽  
Categorical Data ◽  
Clustering Algorithm ◽  
Clustering Algorithms ◽  
Chemical Information ◽  
New Techniques ◽  
Small Set ◽  
Categorical Attributes ◽  
Categorical Attribute ◽  
Numeric Data

A lot of data in real world databases are categorical. For example, gender, profession, position, and hobby of customers are usually defined as categorical attributes in the CUSTOMER table. Each categorical attribute is represented with a small set of unique categorical values such as {Female, Male} for the gender attribute. Unlike numeric data, categorical values are discrete and unordered. Therefore, the clustering algorithms for numeric data cannot be used to cluster categorical data that exists in many real world applications. In data mining research, much effort has been put on development of new techniques for clustering categorical data (Huang, 1997b; Huang, 1998; Gibson, Kleinberg, & Raghavan, 1998; Ganti, Gehrke, & Ramakrishnan, 1999; Guha, Rastogi, & Shim, 1999; Chaturvedi, Green, Carroll, & Foods, 2001; Barbara, Li, & Couto, 2002; Andritsos, Tsaparas, Miller, & Sevcik, 2003; Li, Ma, & Ogihara, 2004; Chen, & Liu, 2005; Parmar, Wu, & Blackhurst, 2007). The k-modes clustering algorithm (Huang, 1997b; Huang, 1998) is one of the first algorithms for clustering large categorical data. In the past decade, this algorithm has been well studied and widely used in various applications. It is also adopted in commercial software (e.g., Daylight Chemical Information Systems, Inc, http://www. daylight.com/).

scholarly journals Clustering Large-Scale Data Based On Modified Affinity Propagation Algorithm

2016 ◽  
Vol 6 (1) ◽  
pp. 23-33 ◽  
Author(s):  
Ahmed M. Serdah ◽  
Wesam M. Ashour
Keyword(s):  
Data Clustering ◽  
Large Scale ◽  
Clustering Algorithm ◽  
Clustering Algorithms ◽  
Affinity Propagation ◽  
Clustering Method ◽  
Data Set ◽  
Local Cluster ◽  
Large Scale Data ◽  
Scale Data

Abstract Traditional clustering algorithms are no longer suitable for use in data mining applications that make use of large-scale data. There have been many large-scale data clustering algorithms proposed in recent years, but most of them do not achieve clustering with high quality. Despite that Affinity Propagation (AP) is effective and accurate in normal data clustering, but it is not effective for large-scale data. This paper proposes two methods for large-scale data clustering that depend on a modified version of AP algorithm. The proposed methods are set to ensure both low time complexity and good accuracy of the clustering method. Firstly, a data set is divided into several subsets using one of two methods random fragmentation or K-means. Secondly, subsets are clustered into K clusters using K-Affinity Propagation (KAP) algorithm to select local cluster exemplars in each subset. Thirdly, the inverse weighted clustering algorithm is performed on all local cluster exemplars to select well-suited global exemplars of the whole data set. Finally, all the data points are clustered by the similarity between all global exemplars and each data point. Results show that the proposed clustering method can significantly reduce the clustering time and produce better clustering result in a way that is more effective and accurate than AP, KAP, and HAP algorithms.

An Ultra-Fast Method for Clustering of Big Genomic Data

2020 ◽  
Vol 11 (1) ◽  
pp. 45-60
Author(s):  
Billel Kenidra ◽  
Mohamed Benmohammed
Keyword(s):  
Dna Methylation ◽  
Large Scale ◽  
Clustering Algorithm ◽  
Clustering Algorithms ◽  
Computational Time ◽  
Fast Method ◽  
Running Time ◽  
Cancer Subtypes ◽  
Biologically Relevant ◽  
High Dimensional Datasets

The clustering process is used to identify cancer subtypes based on gene expression and DNA methylation datasets, since cancer subtype information is critically important for understanding tumor heterogeneity, detecting previously unknown clusters of biological samples, which are usually associated with unknown types of cancer will, in turn, gives way to prescribe more effective treatments for patients. This is because cancer has varying subtypes which often respond disparately to the same treatment. While the DNA methylation database is extremely large-scale datasets, running time still remains a major challenge. Actually, traditional clustering algorithms are too slow to handle biological high-dimensional datasets, they usually require large amounts of computational time. The proposed clustering algorithm extraordinarily overcomes all others in terms of running time, it is able to rapidly identify a set of biologically relevant clusters in large-scale DNA methylation datasets, its superiority over the others has been demonstrated regarding its relative speed.

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