Browsing by Subject "LDA"

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Access status: Open Access ,
Novel approach for big data classification based on hybrid parallel dimensionality reduction using spark cluster
(Wydawnictwa AGH, 2019) Ali, Ahmed Hussein; Abdullah, Mahmood Zaki
The big data concept has elicited studies on how to accurately and efficiently extract valuable information from such huge dataset. The major problem during big data mining is data dimensionality due to a large number of dimensions in such datasets. This major consequence of high data dimensionality is that it affects the accuracy of machine learning (ML) classifiers, it also results in time wastage due to the presence of several redundant features in the dataset. This problem can be possibly solved using a fast feature reduction method. Hence, this study presents a fast HP-PL which is a new hybrid parallel feature reduction framework that utilizes spark to facilitate feature reduction on shared/distributed-memory clusters. The evaluation of the proposed HP-PL on KDD99 dataset showed the algorithm to be significantly faster than the conventional feature reduction techniques. The proposed technique required >1 minute to select 4 dataset features from over 79 features and 3,000,000 samples on a 3-node cluster (total of 21 cores). For the comparative algorithm, more than 2 hours was required to achieve the same feat. In the proposed system, Hadoop’s distributed file system (HDFS) was used to achieve distributed storage while Apache Spark was used as the computing engine. The model development was based on a parallel model with full consideration of the high performance and throughput of distributed computing. Conclusively, the proposed HP-PL method can achieve good accuracy with less memory and time compared to the conventional methods of feature reduction. This tool can be publicly accessed at https://github.com/ahmed/Fast-HP-PL.
Access status: Open Access ,
The acoustic emission (AE) controlling method of the electric sheet blanking process - a comparative study of selected data mining methods
(Wydawnictwa AGH, 2022) Kochański, Andrzej Witold; Czyżewski, Piotr; Moszczyński, Leszek
The article presents an experimental stand to assess the state of punch in the process of sheet blanking. Blanking trials were carried out on an eccentric press. During all the trials, there were recorded signals of acoustic emission (AE) that accompanied the process of blanking. For the recorded AE signals, the methodology of data preparation and analysis was presented. On that basis, the results of the assessment of the state of the punch were presented, and they employed five methods of visualization: Andrews curves, Principal Components Analysis, Linear Discriminant Analysis, a modified method of Stochastic Neighbor Embedding and Sammon Mapping. The aim of the work was to assess the possibility of using visualization methods to predict the condition of the tool on the basis of acoustic emission signals in processes carried out in extremely short times.
Access status: Restricted ,
Zastosowanie metod text miningu do analizy materiałów informacyjnych w kampanii wyborczej
(Data obrony: 2020-10-15) Korczyńska, Martyna
Wydział Zarządzania