DSpace Collection: Volume 7 Number 3
http://hdl.handle.net/10525/2336
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Mapping and Merging of Anatomical Ontologies
http://hdl.handle.net/10525/2343
Title: Mapping and Merging of Anatomical Ontologies<br/><br/>Authors: Petrov, Peter<br/><br/>Abstract: The problem of mapping and merging ontologies in general is an important one in the area of ontology engineering. The same problem considered within the narrower area of anatomical ontologies (AOs) is important in bioinformatics because solving it could enable the transfer of data and the application of knowledge obtained from various model organisms to other model and non-model organisms, and even to research areas such as those of human health and medicine. This paper presents a detailed summary of the author’s PhD research done in the period 2007–2013. The paper’s main topic is the problem of mapping and merging of multiple species-specific AOs and the related approaches, methods, and procedures that can be used for solving it. ACM Computing Classification System (1998): J.3, E.1, G.2.2, G.2.3, I.2.1, I.2.4.<br/><br/>Description: This article presents the principal results of the Ph.D. thesis Intelligent systems in bioinformatics: mapping and merging anatomical ontologies by Peter Petrov, successfully defended at the St. Kliment Ohridski University of Sofia, Faculty of Mathematics and Informatics, Department of Information Technologies, on 26 April 2013.Analysis and Data Mining of Lead-Zinc Ore Data
http://hdl.handle.net/10525/2342
Title: Analysis and Data Mining of Lead-Zinc Ore Data<br/><br/>Authors: Zanev, Vladimir; Topalov, Stanislav; Christov, Veselin<br/><br/>Abstract: This paper presents the results of our data mining study of Pb-Zn (lead-zinc) ore assay records from a mine enterprise in Bulgaria. We examined the dataset, cleaned outliers, visualized the data, and created dataset statistics. A Pb-Zn cluster data mining model was created for segmentation and prediction of Pb-Zn ore assay data. The Pb-Zn cluster data model consists of five clusters and DMX queries. We analyzed the Pb-Zn cluster content, size, structure, and characteristics. The set of the DMX queries allows for browsing and managing the clusters, as well as predicting ore assay records. A testing and validation of the Pb-Zn cluster data mining model was developed in order to show its reasonable accuracy before beingused in a production environment. The Pb-Zn cluster data mining model can be used for changes of the mine grinding and floatation processing parameters in almost real-time, which is important for the efficiency of the Pb-Zn ore beneficiation process.ACM Computing Classification System (1998): H.2.8, H.3.3.Plaintext Recovery in DES-like Cryptosystems Based on S-boxes with Embedded Parity Check
http://hdl.handle.net/10525/2341
Title: Plaintext Recovery in DES-like Cryptosystems Based on S-boxes with Embedded Parity Check<br/><br/>Authors: Angelova, Vesela; Borissov, Yuri<br/><br/>Abstract: We describe an approach for recovering the plaintext in block ciphers having a design structure similar to the Data Encryption Standard but with improperly constructed S-boxes. The experiments with a backtracking search algorithm performing this kind of attack against modified DES/Triple-DES in ECB mode show that the unknown plaintext can be recovered with a small amount of uncertainty and this algorithm is highly efficient both in time and memory costs for plaintext sources with relatively low entropy. Our investigations demonstrate once again that modifications resulting to S-boxes which still satisfy some design criteria may lead to very weak ciphers.ACM Computing Classification System (1998): E.3, I.2.7, I.2.8.A Refinement of some Overrelaxation Algorithms for Solving a System of Linear Equations
http://hdl.handle.net/10525/2340
Title: A Refinement of some Overrelaxation Algorithms for Solving a System of Linear Equations<br/><br/>Authors: Kyurkchiev, Nikolay; Iliev, Anton<br/><br/>Abstract: In this paper we propose a refinement of some successive overrelaxation methods based on the reverse Gauss–Seidel method for solving a system of linear equations Ax = b by the decomposition A = Tm − Em − Fm, where Tm is a banded matrix of bandwidth 2m + 1. We study the convergence of the methods and give software implementation of algorithms in Mathematica package with numerical examples.ACM Computing Classification System (1998): G.1.3.Em Algorithm for MLE of a Probit Model for Multiple Ordinal Outcomes
http://hdl.handle.net/10525/2339
Title: Em Algorithm for MLE of a Probit Model for Multiple Ordinal Outcomes<br/><br/>Authors: Grigorova, Denitsa; Encheva, Elitsa; Gueorguieva, Ralitza<br/><br/>Abstract: The correlated probit model is frequently used for multiple ordered data since it allows to incorporate seamlessly different correlation structures. The estimation of the probit model parameters based on direct maximization of the limited information maximum likelihood is a numerically intensive procedure. We propose an extension of the EM algorithm for obtaining maximum likelihood estimates for a correlated probit model for multiple ordinal outcomes. The algorithm is implemented in the free software environment for statistical computing and graphics R. We present two simulation studies to examine the performance of the developed algorithm. We apply the model to data on 121 women with cervical or endometrial cancer. Patients developed normal tissue reactions as a result of post-operative external beam pelvic radiotherapy. In this work we focused on modeling the effects of a genetic factor on early skin and early urogenital tissue reactions and on assessing the strength of association between the two types of reactions. We established that there was an association between skin reactions and polymorphism XRCC3 codon 241 (C>T) (rs861539) and that skin and urogenital reactions were positively correlated.ACM Computing Classification System (1998): G.3.Test, Teachers, Quorum (Pure Populations)
http://hdl.handle.net/10525/2338
Title: Test, Teachers, Quorum (Pure Populations)<br/><br/>Authors: Radev, Slavian<br/><br/>Abstract: The “trial and error” method is fundamental for Master Minddecision algorithms. On the basis of Master Mind games and strategies weconsider some data mining methods for tests using students as teachers.Voting, twins, opposite, simulate and observer methods are investigated.For a pure data base these combinatorial algorithms are faster then manyAI and Master Mind methods. The complexities of these algorithms arecompared with basic combinatorial methods in AI.ACM Computing Classification System (1998): F.3.2, G.2.1, H.2.1, H.2.8, I.2.6.Symbolic Solving of Partial Differential Equation Systems and Compatibility Conditions
http://hdl.handle.net/10525/2337
Title: Symbolic Solving of Partial Differential Equation Systems and Compatibility Conditions<br/><br/>Authors: Malaschonok, Natasha<br/><br/>Abstract: An algorithm is produced for the symbolic solving of systems of partial differential equations by means of multivariate Laplace–Carson transform. A system of K equations with M as the greatest order of partial derivatives and right-hand parts of a special type is considered. Initial conditions are input. As a result of a Laplace–Carson transform of the system according to initial condition we obtain an algebraic system of equations. A method to obtain compatibility conditions is discussed.