Data Mining Articles

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What is the BLAST Local Alignment Algorithm?

Ginni
Ginni
Updated on 17-Feb-2022 646 Views

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 ...

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Why is it useful to compare and align biosequences?

Ginni
Ginni
Updated on 17-Feb-2022 216 Views

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 ...

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What is GSP?

Ginni
Ginni
Updated on 17-Feb-2022 990 Views

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 ...

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What is sequential pattern mining?

Ginni
Ginni
Updated on 17-Feb-2022 14K+ Views

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 ...

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What is STREAM?

Ginni
Ginni
Updated on 17-Feb-2022 485 Views

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 ...

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What are the methodologies of data streams clustering?

Ginni
Ginni
Updated on 17-Feb-2022 2K+ Views

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 ...

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How does the Lossy Counting algorithm find frequent items?

Ginni
Ginni
Updated on 17-Feb-2022 1K+ Views

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 ...

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What is Randomized Algorithms and Data Stream Management System in data mining?

Ginni
Ginni
Updated on 17-Feb-2022 2K+ Views

Randomized Algorithms − Randomized algorithms in the form of random sampling and blueprint, are used to deal with large, high-dimensional data streams. The need of randomization leads to simpler and more effective algorithms in contrast to known deterministic algorithms.If a randomized algorithm continually returns the correct answer but the running times change, it is called a Las Vegas algorithm. In contrast, a Monte Carlo algorithm has bounds on the running time but cannot restore the true result. It can usually consider Monte Carlo algorithms. The importance of a randomized algorithm is simply as a probability distribution over a group of ...

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What is Sequential Exception Technique?

Ginni
Ginni
Updated on 17-Feb-2022 495 Views

The sequential exception technique simulates the method in which humans can distinguish unusual sets from between a sequence of supposedly like objects. It helps implicit redundancy of the data.Given a data set, D, of n objects, it construct a sequence of subsets, {D1, D2, ..., Dm}, of these objects with 2 ≤ m ≤ n including$$\mathrm{D_{j−1}\subset D_{j}\:\:where\: D_{j}\subseteq D}$$Dissimilarities are assessed between subsets in the series. The technique learns the following terms which are as follows −Exception set − This is the set of deviations or outliers. It is defined as the smallest subset of objects whose removal results in ...

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How can we approach the problem of clustering with obstacles?

Ginni
Ginni
Updated on 17-Feb-2022 233 Views

A partitioning clustering method is desirable because it minimizes the distance among sets and their cluster centers. If it can choose the k-means method, a cluster center cannot be available given the existence of obstacles.For instance, the cluster can turn out to be in the center of a lake. In other words, the k-medoids method chooses an object inside the cluster as a center and thus guarantees that a problem cannot appear.At each time a new medoid is selected, the distance among each object and its newly selected cluster center has to be recalculated. Because there can be obstacles among ...

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