Found 426 Questions for Data Mining

How can generalization be performed on such data?

Updated on 17-Feb-2022 11:53:37
A set-valued attribute can be of homogeneous or heterogeneous type. Generally, set-valued information can be generalized byGeneralization of every value in the set to its equivalent higher-level conceptDerivation of the usual behavior of the set, including the multiple elements in the set, the types or value ranges in the set, the weighted average for statistical data, or the major clusters formed by the set.Furthermore, generalization can be implemented by using several generalization operators to analyse alternative generalization paths. In this method, the result of generalization is a heterogeneous set.Example − Suppose that the hobby of a person is a set-valued ... Read More

What is Multirelational clustering?

Updated on 17-Feb-2022 11:51:46
Multirelational clustering is the phase of partitioning data objects into a group of clusters depends on their similarity, using data in multiple relations. CrossClus represents Cross-relational Clustering with user guidance. It is an algorithm for multirelational clustering that analyse how to use user guidance in clustering and tuple ID propagation to prevent physical joins.The main challenge in multirelational clustering is that there are several attributes in multiple relations, and generally only a small area of them are relevant to a definite clustering task.It can cluster students, attributes cover several elements of information, including courses taken by students, publications of students, ... Read More

What is Tuple ID Propagation?

Updated on 17-Feb-2022 11:49:00
Tuple ID propagation is an approach for implementing virtual join, which highly improves effectiveness of multirelational classification. Rather than physically joining relations, they are virtually combined by connecting the IDs of target tuples to tuples in non-target relations.In this method the predicates can be computed as if a physical join were implemented. Tuple ID propagation is flexible and effectiveness, because IDs can simply be propagated between some two relations, needing only small amounts of data transfer and more storage space. By doing so, predicates in multiple relations can be computed with small redundant computation.Tuple ID propagation must be enforced with ... Read More

What is the BLAST Local Alignment Algorithm?

Updated on 17-Feb-2022 11:47:02
The BLAST algorithm was produced by Altschul, Gish, Miller, around 1990 at the National Center for Biotechnology Information (NCBI). BLAST is used to derive functional and evolutionary relationships among sequences and to help recognize members of gene families.The NCBI website includes several common BLAST databases. As per their content, they are combined into nucleotide and protein databases. NCBI also supports specialized BLAST databases including the vector screening database, there are several genome databases for multiple organisms, and trace databases.BLAST uses a heuristic approaches to discover the largest local alignments between a query sequence and a database. BLAST increase the complete ... Read More

Why is it useful to compare and align biosequences?

Updated on 17-Feb-2022 11:45:18
The alignment depends on the fact that all living organisms are associated by evolution. This uses that the nucleotide (DNA, RNA) and proteins series of the species that are nearer to each other in evolution must exhibit higher similarities.An alignment is the phase of lining up sequences to obtain a maximal level of identity, which also defines the degree of similarity among sequences. There are two sequences are homologous if they send a common ancestor.The degree of similarity acquired by sequence alignment can be beneficial in deciding the possibility of homology among two sequences. Such an alignment support decide the ... Read More

What is GSP?

Updated on 17-Feb-2022 11:42:10
GSP stands for Generalised Sequential Patterns. It is a sequential pattern mining method that was produced by Srikant and Agrawal in 1996. It is an expansion of their seminal algorithm for usual itemset mining, referred to as Apriori. GSP needs the downward-closure natures of sequential patterns and adopts a several-pass, students create-and-test approach.The algorithm is as follows. In the first scan of the database, it can discover some frequent items, i.e., those with minimum support. Each item yields a 1-event frequent sequence including that item. Each subsequent pass begins with a seed group of sequential patterns and the group of ... Read More

What is sequential pattern mining?

Updated on 17-Feb-2022 11:39:40
Sequential pattern mining is the mining of frequently appearing series events or subsequences as patterns. An instance of a sequential pattern is users who purchase a Canon digital camera are to purchase an HP color printer within a month.For retail information, sequential patterns are beneficial for shelf placement and promotions. This industry, and telecommunications and different businesses, can also use sequential patterns for targeted marketing, user retention, and several tasks.There are several areas in which sequential patterns can be used such as Web access pattern analysis, weather prediction, production processes, and web intrusion detection.Given a set of sequences, where each ... Read More

What is STREAM?

Updated on 17-Feb-2022 11:38:00
STREAM is an individual-pass, constant element approximation algorithm that was produced for the k-medians problem. The k-medians problem is to cluster N data points into k clusters or groups such that the sum squared error (SSQ) between the points and the cluster center to which they are assigned is minimized. The idea is to assign similar points to the same cluster, where these points are dissimilar from points in other clusters.In the stream data model, data points can only be seen once, and memory and time are limited. It can implement high-quality clustering, the STREAM algorithm processes data streams in ... Read More

What are the methodologies of data streams clustering?

Updated on 17-Feb-2022 11:36:08
Data stream clustering is described as the clustering of data that appar continuously including telephone data, multimedia data, monetary transactions etc. Data stream clustering is generally treated as a streaming algorithm and the objective is, given a sequence of points, to make a best clustering of the stream, utilizing a small amount of memory and time.Some applications needed the automated clustering of such data into set based on their similarities. Examples contains applications for web intrusion detection, analyzing Web clickstreams, and stock market analysis.There are several dynamic methods for clustering static data sets clustering data streams places additional force on ... Read More

How does the Lossy Counting algorithm find frequent items?

Updated on 17-Feb-2022 11:32:55
A user supports two input parameters including the min support threshold, σ, and the error bound previously, indicated as ε. The incoming stream is theoretically divided into buckets of width w = [1/ε].Let N be the current stream length, i.e., the number of items view so far. The algorithm needs a frequency-list data structure for all elements with frequency higher than 0. For every item, the list supports f, the approximate frequency count, and ∆, the maximum possible error of f.The algorithm procedure buckets of items as follows. When a new bucket arrives in, the items in the bucket are ... Read More