Online archive

Computer Science and Mathematical Modelling No. 1/2015

  1. A. Ameljańczyk - Pareto filter in the process of multi-label classifier synthesis in medical diagnostics support algorithms
    Pages: 5 - 10
    Abstract: The paper presents the possibility of using multi-criteria optimization methods for simple classifiers fusion in a more precise and reliable classifiers complex. There are defined simple classifiers (one label) in the form of classifier committees and sample the synthesis relations of classifiers allow to obtain classifiers filed with improved properties.
    Keywords Pareto filter, medical diagnostics, the committee classifiers, classifiers synthesis, not dominated diagnosis
    Full article: PDF icon 5_10_aameljanczyk_csmm_1_2015.pdf
  2. A. Ameljańczyk - Property analysis of multilabel classifiers in the example of determining the initial medical diagnosis
    Pages: 11 - 16
    Abstract: In the paper analysis of properties of medical diagnoses acquired using simple and complex classifiers was performed. The introduced terms are illustrated with a comprehensive example in the field of medical diagnostics.
    Keywords medical diagnostics, committee classifiers, synthesis of classifiers, not dominated diagnosis classifier reliability
    Full article: PDF icon 11_16_aameljanczyk_csmm_1_2015.pdf
  3. A. Chojnacki, G. Pieniążek - Time based deterministic model of information security of a business organization
    Pages: 17 - 24
    Abstract: This paper discusses information security of a business organization using a time-based mathematical deterministic model. The model addresses key features of a business organization from the point of view of information security and calculates the level of information security based on quantitative values. Next, the introduced model is used to evaluate the level of information security that could be achieved for known threats within a given budget. For this reason, an optimization problem of safeguard implementation is formulated and an optimization method based on dynamic programming is used to address the issue. Two samples, local and global security metrics, defined in the model are described and one of them is used in optimizing safeguard implementation.
    Keywords information security, deterministic model, dynamic programming
    Full article: PDF icon 17_24_achojnacki_gpieniazek_csmm_1_2015.pdf
  4. M. Chudy - Model of attrition process control
    Pages: 25 - 30
    Abstract: The essence of the presented attrition process control relies on the solving defined sequence of target assignment problems at specific moments. The sequence of these moments is obtained for both sides of the battle. The model takes into account the changes of the number of means and targets as well as changes in environmental conditions. It is reflected in the parameters of problems. Each of the considered assignment problems belongs to the class of general assignment problems which does not contain totally unimodular matrix factors.
    Keywords mathematical modeling, attrition process, assignment problem
    Full article: PDF icon 25_30_mchudy_csmm_1_2015.pdf
  5. T. Rzeźniczak - Evolutionary algorithms for Map of Attributes optimization
    Pages: 31 - 43
    Abstract: Map of Attributes (MoA) is a visualization technique that allows to construct graphical representation of abstract entities. The technique is intended to aid recognition of the entities’ representations through the effective use of human perception abilities. A certain difficulty in the application of MoA is the computational complexity of finding an optimal map. The study presents a heuristic approach, based on evolutionary algorithms (EA), to constructing MoA visualization. The method was evaluated using the repository of disease entities as an input dataset. Several different setups of EA were tested; these were configurations with well-known evolution operators, as well as setups with newly proposed operators for the matrix representation of chromosome. Detailed results and analysis of conducted experiments are presented.
    Keywords evolutionary algorithms, data visualization, evolution operators
    Full article: PDF icon 31_43_trzezniczak_csmm_1_2015.pdf

Computer Science and Mathematical Modelling No. 2/2015

  1. A. Ameljańczyk - Mathematical aspects of ranking theory
    Pages: 5 - 10
    Abstract: The paper covers the theoretical grounds for defining of rankings, basing on the terms taken from the relation space theory. One presented an array of new definitions which allow establishing rankings without the necessity of using typical ranking functions. Moreover, one introduced the term precedence ranking relation (not necessarily order relation), and demonstrated general algorithms to establish rankings on the basis of definitions of extreme elements.
    Keywords precedence ranking relation, pseudo ranking, linear ranking, extreme elements, data clustering
    Full article: PDF icon 5_10_aameljanczyk1_csmm_2_2015_p.pdf
  2. A. Ameljańczyk, Ch. Trang Quang - Lexicographical binary implementation of the Recurrent Pareto Filter in categorization procedures
    Pages: 11 - 15
    Abstract: The paper presents the possibility of using Recurrent Pareto Filter (RPF) to the categorization procedures of objects (data). The paper presents a new implementation of the RPF algorithm, that uses lexicographical sorting objects and binary search Pareto optimal elements. The functioning of the algorithm illustrated by an example categorization procedure of scientific journals contained in the Scimago Scientific Journals Base.
    Keywords Pareto filter, data clustering, multi-criteria ranking, categorization of objects, recurrent Pareto filter
    Full article: PDF icon 11_15_aameljanczyk2_csmm_2_2015_p.pdf
  3. M. Chudy - Model of attrition process in the presence of decoy
    Pages: 17 - 21
    Abstract: Mutual destroying process on a battlefield has classically been modeled without accounting for the possible presence of false targets. Following [6] we include into consideration the presence of decoys. Attrition of human decoys is to be strenuously avoided for humanitarian reasons, but also because of its broad impact on world opinion. False targets should be taken into consideration in the formulation of the target assignment problems. We formulate bicriteria assignment problem. First of them maximizes expected value of destroyed correctly detected targets and the second minimizes expected value of destroyed incorrectly detected targets. The resulting problem provides the set of compromise solutions. Each of the considered assignment problems belong to the class of general assignment problem which does not contain totally unimodular matrix factors.
    Keywords mathematical modeling, attrition process, assignment problem, decoy
    Full article: PDF icon 17_21_mchudy_csmm_2_2015_p.pdf
  4. M. Furmankiewicz, J. Furmankiewicz, P. Ziuziański - Evaluation of expert system as a stage of life cycle model ESDLC on the example of WIKe
    Pages: 23 - 32
    Abstract: The purpose of the article is to present the Expert System Development Life Cycle (ESDLC) and – in particular – the ESDLC’s evaluation stage. The essence of expert systems has been briefly described in the Artificial Intelligence (AI) context. Authors concentrated on the WIKex expert system, which was a practical part of the master’s thesis submitted by one of the authors of the University of Economics in Katowice. Moreover, the results of WIKex evaluation have been presented as a the last stage of the life cycle of the expert system.
    Keywords expert system, ESDLC, WIKex
    Full article: PDF icon 23_32_furmankiewicz_evaluation_csmm_2_2015_p.pdf
  5. T. Rzeźniczak - Visual analysis techniques diagnosis support
    Pages: 33 - 41
    Abstract: Taking into account vast amount of data available for general practitioners, medical diagnostic procedure can be treated as a complex analytical task. A doctor has to analyze the patient’s symptoms, medical test results, and medical knowledge, correlate everything and decide on the diagnosis. In order to do this more effectively, dedicated analytical tools and techniques can be used. The paper elaborates on the application of Map of Attributes (MoA) visualization technique for analysis of a patient’s health and disease pattern recognition. Various modes of using MoA are proposed and discussed. Furthermore, an application of diseases ranking preparation methods in visual filtering of diseases is presented. The methods use flexible similarity indices in conjunction with a graphical presentation of the Pareto model and Multidimensional Scaling model. Their goal is to allow physicians to narrow the space of detailed analysis in an interactive visual manner.
    Keywords data analysis, data visualization, medical decision support
    Full article: PDF icon 33_41_trzezniczak_csmm_2_2015_p.pdf

Computer Science and Mathematical Modelling No. 3/2016

  1. K. Antczak - Rank thresholds in classifier ensemles in medical diagnosis
    Pages: 5 - 12
    Abstract: Classification methods have multiple applications, with medical diagnosis being one of the most common. A powerful way to improve classification quality is to combine single classifiers into an ensemble. One of the approaches for creating such ensembles is to combine class rankings from base classifiers. In this paper, two rank-based ensemble methods are studied: Highest Rank and Borda Count. Furthermore, the effect of applying class rank threshold to these methods is analyzed. We performed tests using real-life medical data. It turns out that specificity of data domain can affect classification quality depending on classifier type.
    Keywords medical diagnostics, classifier ensemble, rank threshold
    Full article: PDF icon 5_12_csmm3.pdf
  2. A. Chojnacki, G. Pieniążek - Choosing the optimal strategy for information security in a business organization
    Pages: 13 - 22
    Abstract: The paper describes the method of choosing the optimal strategy to implement security measures in a business organization. Strategies are categorized depending on time horizons, the history of threats and implemented security measures. Next, the method of choosing the optimal strategy for a business organization in a given context is outlined. Then this method is used to select the optimal strategy in a particular business context. The method is based on a deterministic time-based information security model, which was extended to a random model. With this simulation method, an organization can choose a strategy to implement security measures that best suits its needs. It is important for organizations to conduct an analysis of costs and threats in order to select appropriate safeguards.
    Keywords information security, stochastic model, simulation
    Full article: PDF icon 13_22_csmm3.pdf
  3. J. Dygaszewicz, B. Szafrański - Introducing Enterprise Architecture Framework in Statistics Poland
    Pages: 23 - 32
    Abstract: Article is devoted to the modernization of the statistical production process. The starting point for formulating the principles and methods of the modernization is to establish a framework architecture. An in-depth analysis of all relevant aspects arising from the holistic approach to the production of statistics is essential to extract the key business issues. Business needs are the foundation for the formulation of a coherent and transparent guidelines, demands, legal and technical requirements, both domestic and international which are the basis for the construction of the enterprise architecture framework and the development of solutions used to carry out the tasks of public statistics. The process of constructing architectural framework requires the use of models and methods used in scientific research, in particular arising from the achievements of enterprise architecture and modeling tools for object-oriented computing.
    Keywords enterprise architecture framework, statistics survey, GSBPM, TOGAF
    Full article: PDF icon 23_32_csmm3.pdf
  4. R. Kasprzyk, A. Stachurski - A concept of standard-based vulnerability management automation for IT systems
    Pages: 33 - 38
    Abstract: The paper focuses on the attempt to show a way of automating IT vulnerability management across enterprise systems with the use of the Security Content Automation Protocol. SCAP offers a set of components which provide, among others, adjustable security checklists, standardised dictionaries of security vulnerabilities and vulnerability scoring methods that may prove valuable for organisations in terms of security analysis activities and quantitative risk assessment.
    Keywords vulnerabilities, SCAP, security
    Full article: PDF icon 33_38_csmm3.pdf
  5. M. Zabielski, Z. Tarapata, R. Kasprzyk, K. Szkółka - Profile Cloning Detection in Online Social Networks
    Pages: 39 - 46
    Abstract: Due to the emergenceof online social networks, the importance of privacy on the Internet has vitally increased. Thus, it is important to develop mechanisms that will prevent our hidden personal data from unauthorized access and use. In this paper an attempt was made to present a concept of profile cloning detection in Online Social Networks (OSN) using Graph and Network Theory. Compering values of attributes of users’ personal profiles and analysing structural similarity of networks, we identifyattackers which steal users’ identity.
    Keywords profile cloning detection, online social networks, violations of privacy
    Full article: PDF icon 39_46_csmm3.pdf

Computer Science and Mathematical Modelling No. 4/2016

  1. A. Ameljańczyk - Presorting as a method of acceleration of algorithms in multi-objective optimization problems
    Pages: 5 - 11
    Abstract: The paper presents a method of algorithms acceleration for determining Pareto-optimal solutions (Pareto Front) multi-criteria optimization tasks, consisting of pre-ordering (presorting) set of feasible solutions. It is proposed to use the generalized Minkowski distance function as a presorting tool that allows build a very simple and fast algorithm Pareto Front for the task with a finite set of feasible solutions.
    Keywords Pareto Front, presorting, Minkowski metric
    Full article: PDF icon 5_11_csmm_4_aameljanczyk.pdf
  2. M. Chudy - Branch and Bound method for binary problems with the picture that redudes dimensions of problem
    Pages: 13 - 18
    Abstract: The relationships between elements of coefficient matrix, elements of vector and elements of vector in general binary problem are considered. Some of them allow us to establish the values of selected elements of feasible or optimal vector . This procedure reduces the dimension of basic problem and can be install in branch and bound method. It gives positive effects.
    Keywords binary problem, branch and bound method, reducing dimension
    Full article: PDF icon 13_18_csmm_4_mchudy.pdf
  3. O. Dzięgielewska, B. Szafrański - A brief overview of basic inference attacks and protection controls for statistical databases
    Pages: 19 - 24
    Abstract: With cyber-attacks on the dramatic rise in the recent years, the number of entities which realize the necessity of protecting their IT assets increases. Individuals are more aware of the potential threats and demand high level of security from the business entities having access to their personal and private data. Such entities have legal obligations to satisfy the confidentiality when processing sensitive data, but many fails to do so. Keeping the statistical data private is a challenge as the approach to the security breaches slightly differs from the classical understanding of data disclosure attacks. The statistical disclosure can be achieved using inference attacks on the not-effectively protected assets. Such attacks do not target the database access itself, i.e. are performed from a perspective of an internal user, but the statistical interface used to retrieve the statistical data from the database records. This paper sums up basic types of inference attacks classifying them in the CVSS standard and provides a series of fundamental countermeasures which can be undertaken to mitigate the risk of performing successful attack.
    Keywords statistical databases, inference control in statistical database, statistical disclosure, data security, data privacy.
    Full article: PDF icon 19_24_csmm_4_odziegielewska_bszafranski.pdf
  4. B. Szafrański, J. Wilk - Electronic services security management for the public administration
    Pages: 25 - 32
    Abstract: The public administration in Poland is constantly extending and improving electronic services provided to citizens, business and itself (e.g. one ministry providing services to another public administration institution). New expectations like integration using the multilateral interoperability model, the service oriented approach, different security categories and groups within different institutions are creating the requirement for the appropriate security model. According to the authors current models do not meet the new requirements, but can be used as a base for the new approach. The lattice and its variations in different models (Denning, Sandhu, Szafrański) was selected by authors to create the new electronic services security management model for integration platforms which are supporting realization of public tasks. This publication focuses on practical aspect of the new model and presents the case study on a public administration e-services example. Detailed definition of the model itself can be found in previous authors’ articles.
    Keywords e-services, security, SOA
    Full article: PDF icon 25_32_csmm_4_bszafranski_jwilk.pdf
  5. M. Wroński - Using Montgomery curve arithmetic over Fp2 for point scalar multiplication on short Weierstrasscurve over Fp with exactly one 2 – torsion point and order not divisible by 4 for IT systems
    Pages: 33 - 38
    Abstract: Montgomery curves are well known because of their efficiency and side channel attacks vulnerability. In this article it is showed how Montgomery curve arithmetic may be used for point scalar multiplication on short Weierstrass curve ESW over Fp with exactly one 2-torsion point and not divisible by 4. If then also . Because has three 2-torsion points (because has one 2-torsion point) it is possible to use 2-isogenous Montgomery curve to the curve for counting point scalar multiplication on . However arithmetic in is much more complicated than arithmetic in , in hardware implementations this method may be much more useful than standard methods, because it may be nearly 45% faster.
    Keywords elliptic curve cryptography, hardware implementations, Montgomery curves
    Full article: PDF icon 33_38_csmm_4_m_wronski.pdf

Computer Science and Mathematical Modelling No. 5/2017

  1. P. Augustynowicz, A. Buraczyńska - Comparison between experimental, analytical and simulation model of distributed computation on ARM processors in High-Performance Computing
    Pages: 5 - 10
    Abstract: The paper presents a comparison between experimental, analytical and simulation model of distributed cryptographic computation regarding password recovery with SHA 1 password hashing. The aim of this paper is compare popular mobile ARM processors with their Intel Atom analogue and determine their usefulness in cryptographic computations from High Performance Computing (HPC) point of view. During the construction process of HPC cluster, three different versions of Raspberry Pi computers were used. Then the constructed model was applied to develop an analytical and simulation models that allow calculating most influential characteristics from HPC clusters administrator’s point of view. Reference model was constructed on Intel Atom processors.
    Keywords ARM processors, High-Performance Computing, Analytical Model
    Full article: PDF icon 5_10_csmm_5_paugustynowicz.pdf
  2. K. Banach, R. Kasprzyk - Software environment for rapid prototyping of graph and network algorithms
    Pages: 11 - 16
    Abstract: The article presents an innovative software environment for rapid prototyping of graph and network algorithms. The environment consists of two main components: an editor of graphs & networks and an editor of algorithms’ code. The presented environment enables interactive visualization of algorithms implemented therein, which in turn allows quick verification of algorithms results as well as its correctness. The aim of the environment construction was to provide a solution for rapid prototyping of novel algorithms. The developed tool can also be successfully used for educational purposes.
    Keywords graph and network theory, algorithms prototyping, algorithms visualization
    Full article: PDF icon 11_16_csmm_5_kbanach_rkasprzyk.pdf
  3. D. Dzida - Using complex networks in social impact models
    Pages: 17 - 28
    Abstract: This paper describes models of opinion dynamics. It presents various ways of modelling opinion spreading in the population. The author proposes to apply complex networks to a model, which is based on the theory of social impact. The agent based modelling is applied to construct the model and perform simulations. Performed simulations allowed to investigate how the use of complex networks and its properties have an influence on the final distribution of opinions in the population. The results of simulations have been shown and interpreted.
    Keywords social impact model, social simulation, opinion dynamics, complex networks
    Full article: PDF icon 17_28_csmm_5_ddzida.pdf
  4. P.A. Ryszawa - On sentence membership problem in context sensitive languages
    Pages: 29 - 44
    Abstract: A new type of graph is introduced, the grammar graph. The possibility of assigning labels to each node in such a graph extends it to the grammar net. The grammar net should be considered as a new graphical tool that helps in an analysis of whether a particular sentence belongs to a given context-sensitive grammar. Another concept, the derivation net, closely related to the grammar graph and of a similar structure, will be used to show an algorithm that is able to decide that some sentences do not belong to a language generated by a context sensitive grammar, while leaving others as a candidate members of it.
    Keywords context-sensitive grammar, non-contracting grammar, formal language, graph, parsing
    Full article: PDF icon 29_44_csmm_5_pryszawa.pdf
  5. P. Wołoszyn - Assessment of ranking algorithms in complex networks
    Pages: 45 - 51
    Abstract: A particularly helpful search of a network such as the Internet or a citation network not only finds nodes that satisfy some criteria but also ranks those nodes for importance to create what amounts to a “reading list”. In the recent past, there has been a large interest across a number of research communities in the analysis of complex networks. The selected set of pages from the World Wide Web can be modeled as a directed graph, where nodes are designated as individual pages, and the links as a connection between them. As the number of webpages to be ranked is in the billions, the computation is time-consuming and can take several days or more. Algorithms like PageRank, HITS, SALSA and their modifications has a challenge to deal with the size of the processed data. The need for accelerated algorithms is clear. This article presents the characteristics of three best known ranking algorithms and the assumptions for new algorithm development with first test runs.
    Keywords link analysis, web search, HITS algorithm, Kleinberg’s HITS algorithm, PageRank algorithm, SALSA algorithm, hubs, authorities.
    Full article: PDF icon 45_51_csmm_5_pwoloszyn.pdf

Computer Science and Mathematical Modelling No. 6/2017

  1. M. Chudy - Economical assigning weapons to targets
    Pages: 5 - 8
    Abstract: Some upper and lower bound are proposed to use in branch and bound method for solving Weapon-Target Assignment (WTA) problems. Analyze of WTA inspires to formulate another problem to economize the number of weapons under the condition that the establish threshold value of destroying targets is achieved. This requirement generates an additional constrain generating the set of feasible solutions of WTA.
    Keywords WTA problem, assignment, economize
    Full article: PDF icon 5_8_mchudy_economical_csmm_6.pdf
  2. O. Dzięgielewska - Anonymization, tokenization, encryption How to recover unrecoverable data
    Pages: 9 - 13
    Abstract: The data privacy is currently vastly commented topic among all the organizations which process personal data due to the introduction of the European Union’s General Data Protection Regulation. Existing methods of data protection are believed to be sufficient as they meet the risk-based approach requirements in every mature organization, yet the number of publicly known data breaches confirms that this assumption is false. The aftermath of such incidents in countless cases prove that the risk-based approach failed as the reputational and financial consequences by far exceed the original estimations. This paper stressed the importance of the data layer protection from the planning, through design, until maintenance stages in the database lifecycle, as numerous attack vectors originating from the insider threat and targeting the data layer still sneak through unnoticed during the risk analysis phase.
    Keywords database lifecycle, inference attacks, data privacy, data breaches, GDPR
    Full article: PDF icon 9_13_odziegielewska_csmm_6.pdf
  3. P.A. Ryszawa - Discovering grammar of an unknown text as an optimisation problem
    Pages: 15 - 22
    Abstract: This paper concerns the problem of discovering an unknown grammar from a text sample. The discovering methods are formulated as optimisation problems based on a binary representation of context-sensitive grammars. The representation starts with a longest possible vector of bits to, finally, make it more compact so as to be usable in practical applications. For the sake of simplicity, considered are only noncontracting (length preserving) grammars of order 2, excluding productions of the form P:A→B and those deriving the empty string, i.e P:A→ε.
    Keywords context-sensitive language, formal grammar, noncontracting grammar, binary representation, optimisation problem
    Full article: PDF icon 15_22_pa_ryszawa_csmm_6.pdf
  4. R. Waszkowski, R. Kasprzyk, T. Tarnawski - Spread Page approach to Business Process Management
    Pages: 23 - 32
    Abstract: Recently, we have observed a slow departure from printed texts towards electronic publications. Such content may be presented in many ways, including time-dependent 3D representation, aspect representation, layer representation and multi-resolution representation. Spread Page Initiative refers to the development of notation and tools for knowledge representation in a modern manner not limited by using the traditional paper-oriented technique. The article describes the Spread Page approach to the modeling of business processes. The authors consider a possibility of using new ways of knowledge representation to ensure accurate and more precise modeling of business processes.
    Keywords Spread Page, knowledge representation, Business Process Management
    Full article: PDF icon 23_32_rwaszkowski_csmm_6.pdf
  5. T. Tarnawski, R. Kasprzyk, R. Waszkowski - Foundations for Spread Page: review of existing concepts, solutions, technologies capable of improving effectiveness of conveying knowledge
    Pages: 33 - 44
    Abstract: Spread Page is our code name for a new, more efficient way of conveying technical information and scientific knowledge – freed form the text-centered mindset and focused on graphical, interactive, multidimensional representation. The article presents an overview of current concepts and solutions that seem applicable in crafting the idea of Spread Page. In our discussion we begin with novel, abstract, organizational ideas regarding the process of creating and disseminating scientific knowledge, that break up with the traditional model of (paper) publishing. Then we turn to analyzing methods and conventions used in (graphically) modeling real and abstract constructs, and finally review existing software solutions, technologies and exemplary, concrete products that implement certain functionalities instrumental to our cause. We reach the conclusion that, in certain areas (dealing with read-world entities, e.g. mechanics or anatomy), such desired “Spread-Page” way of representing knowledge is already within our reach. In more abstract fields, like law and legislature, political science, etc. we are still far off, mostly due to lack of appropriate standards and (graphical) notation. The paper is as a part of a larger set of articles presenting the proposed concept of Spread Page.
    Keywords graphical knowledge representation, Spread Page
    Full article: PDF icon 33_44_ttarnawski_csmm_6.pdf

Computer Science and Mathematical Modelling No. 7/2018

  1. A. Ameljańczyk - The solutions similarity of the similar conflicts
    Pages: 5 - 10
    Abstract: The work deals with the examination of solutions similarity of similar conflicts, presented in the form of multiperson cooperative games. There is examined the similarity of the two most well-known in the literature concepts of the cooperative game solutions: Shapley solution and nucleolus (Schmeidler solution [9]). The work presents an idea of using a solution of the pattern conflict most similar to the considered conflict as a its solution.
    Keywords model of conflict, cooperative game, similarity of conflicts, ideal game, pattern recognition.
    Full article: PDF icon 5_10_aameljanczyk_csmm_7.pdf
  2. A. Horubała, D. Waszkiewicz, M. Andrzejczak, P. Sapiecha - Data confidentiality and computations hiding in cloud services for public administration
    Pages: 11 - 18
    Abstract: Cloud services are gaining interest and are very interesting option for public administration. Although, there is a lot of concern about security and privacy of storing personal data in cloud. In this work mathematical tools for securing data and hiding computations are presented. Data privacy is obtained by using homomorphic encryption schemes. Computation hiding is done by algorithm cryptographic obfuscation. Both primitives are presented and their application for public administration is discussed.
    Keywords public administration, obfuscation, homomorphic encryption.
    Full article: PDF icon 11_18_andrzejczak_horubala_sapiecha_waszkiewicz_csmm_7.pdf
  3. M. Miecznik, J.W. Mietelski, E. Łokas, K. Kleszcz - Modeling of the Cs137 and Sr90 contamination transportation process performed for the vicinity of National Radioactive Wastes Disposal in Różan (NE Poland)
    Pages: 19 - 30
    Abstract: This paper contains the results of radionuclides transportation modeling under National Radioactive Waste Disposal (NRWD) grounds in Różan (northeast Poland). The disposal is of the low- and intermediate-level waste (LILW) type. We simulated the radionuclides transportation process through sandy soils. The simulation was performed in a self-written simulator in Scilab using the finite difference method. The model included diffusion, advection and radioactive decay. The model was tested according to convergence and stability. Assuming the hydrological gradient being 0.008, the contamination transportation time was 30–46 years depending on the modeled problem. The modeled distance of 600 m was from underneath the disposal to the exudation in the Narew ravine. Radioactive decay for both cesium (Cs137) and strontium (Sr90) had a significant impact on the results. The model proved to be a useful tool for performing simple scientific simulations. This survey was part of a PhD thesis.
    Keywords advection, diffusion, radioactive decay.
    Full article: PDF icon 19_30_mmiecznik_csmm_7.pdf
  4. P.A. Ryszawa - Modelling quantum register disentanglement
    Pages: 31 - 44
    Abstract: Implementing quantum-inspired algorithms on classical computers suffers trade-off between the necessity of saving operational memory and the amount of memory necessary to fully represent a quantum state with possible entanglement. The latter is well known to consume the memory exponentially in the number of qubits. This paper sketches out the idea on how to reduce significantly the amount of necessary memory while distorting the entanglement moderately or not at all. At present, considered are real nonnegative probability amplitudes.
    Keywords quantum computing, quantum entanglement, disentanglement, quantum register.
    Full article: PDF icon 31_44_pryszawa_csmm_7_v2.pdf
  5. B. Szafrański, M. Zieja, J. Wójcik, K. Murawski - Data analysis of information system TURAWA in the aspect of data mining methods
    Pages: 45 - 52
    Abstract: The article is devoted to the analysis of data coming from the operation process and collected in computer system TURAWA, which focuses on supporting the management of flight safety in the Polish Air Force. The Armed Forces are equipped with a system, which collects and processes data concerning the whole air crew, all performed flights and all aircraft. The increasing opportunities in obtaining data and the continuous development of data mining methods allow to extract information never been known before, which, together with conclusions obtained from the data analysis, will help to improve the level of flight safety.
    Keywords flight safety, data mining, TURAWA.
    Full article: PDF icon 45_52_jwojcik_csmm_7.pdf

Computer Science and Mathematical Modelling No. 8/2018

  1. F. Darnowski, A. Chojnacki - Writing and Deleting files on hard drives with NTFS
    Pages: 5 - 15
    Abstract: The goal of this article was to present detailed information about writing and deleting process on the NTFS (New Technology File System) formatted drives. The most important are the algorithms used by computer to write data BFA (Best Fit Algorithm) and FFA (First-Free Algorithm) to update $MFT (Master File Table). The naming convention of the areas of the drive is presented. The proposed rules of writing and deleting algorithm were successfully validated with real NTFS volume.
    Keywords hard disk, NTFS, $MFT.
    Full article: PDF icon 5_15_new_ach_fd_csmm_8_p.pdf
  2. M. Jankowski - Ensemble Methods for Improving Classification of Data Produced by Latent Dirichlet Allocation
    Pages: 17 - 28
    Abstract: Topic models are very popular methods of text analysis. The most popular algorithm for topic modelling is LDA (Latent Dirichlet Allocation). Recently, many new methods were proposed, that enable the usage of this model in large scale processing. One of the problem is, that a data scientist has to choose the number of topics manually. This step requires some previous analysis. A few methods were proposed to automatize this step, but none of them works very well if LDA is used as a preprocessing for further classification. In this paper, we propose an ensemble approach which allows us to use more than one model at prediction phase, at the same time, reducing the need of finding a single best number of topics. We have also analyzed a few methods of estimating topic number.
    Keywords Dimensionality reduction, classification, machine learning, natural language processing, topic modelling.
    Full article: PDF icon 17_28_mjankowski_ensemble_csmm_8_2018_p.pdf
  3. D. Pierzchała, P. Czuba - Method of agents’ state estimation in multiresolution multiagent simulation
    Pages: 29 - 39
    Abstract: The paper proposes the multiagent techniques for approximation of agent’s state in the multiresolution multiagent simulation. The key methods we have used for state aggregation and disaggregation are: consensus algorithm and formation control. The idea of the coordination of multiple agents has emerged from both observation and simulation of a collective behavior of biological entities. The consensus algorithms are commonly used for the cooperative control problems in the multiagent systems, whilst the formation control is the most popular and fundamental motion coordination problem in the multiagent systems, where agents converge to predefined geometric shapes. The presented approach shows that multiagent methods seem to be very promising in multiresolution simulation. Consensus and formation control algorithms remove necessity to specify the much more complex algorithms for the aggregation and disaggregation needs.
    Keywords multiresolution multiagent simulation, multiagent systems, multiagent networks, formation control.
    Full article: PDF icon 29_39_method_of_agents_csmm_8_p.pdf
  4. P.A. Ryszawa - On some specific cases of quantum state in testing its separability
    Pages: 41 - 46
    Abstract: This paper shows a simple computational scheme for determining whether a particular quantum state in a specific form is separable across two given sets of qubits. That is, given a set of qubits partitioned into two, it answers the question: does the original state have a separable form as a tensor product of some two other states, which are set up of the two given subsets of qubits?
    Keywords quantum computing, quantum register, quantum entanglement, quantum separability.
    Full article: PDF icon 41_46_paryszawa_qseparable_csmm_8_2018_p.pdf
  5. K. Sosnowski - The use of electroencephalography as a future-oriented brain-computer interface. Current concepts, solutions, technologies that allow communication through thoughts
    Pages: 47 - 52
    Abstract: Nowadays, brain-computer interfaces are gaining more and more popularity. Research centers develop new methods of human communication with devices through thoughts. There are many methods used for this kind of interfaces, however, the most widespread is electroencephalography (EEG). There are many reasons for this fact, it is a method that is relatively cheap compared to other methods. Less complex technical tools and apparatus are required to operate it. Another advantage of this method, unlike others, is its non-invasiveness. Unfortunately, current brain-computer interfaces do not offer high data rates. However, time plays a smaller role when we are dealing with a disabled person who regains the ability to communicate with the world through the interface controlled by thoughts. This paper is the beginning of a series of papers in which the author will describe in detail the elements of brain-computer interfaces, as well as improvements that can be applied to them to improve their properties.
    Keywords Brain-computer interface, BCI, Electroencephalography, EEG.
    Full article: PDF icon 47_52_theuseofelectro_csmm_8_2018_p.pdf

Computer Science and Mathematical Modelling No. 9/2019

  1. A. Ameljańczyk - Fuzzy set in modeling of patient’s disease states.
    Pages: 5 - 11
    Abstract: The paper concerns the mathematical modeling of patient’s disease states and disease unit patterns for the needs of algorithms supporting medical decisions. Due to the specificity of medical data and assessments in the modeling of patient’s disease states as well as diseases, the fuzzy set methodology was used. The paper presents a number of new characteristics of fuzzy sets allowing to assess the quality of medical diagnosis. In addition, a definition of a multi-aspect fuzzy set is presented, which may be useful in supporting medical diagnostics based on multi-criteria similarity models. The presented results can be used in the construction of algorithms for assessing the patient's state of health and mainly in the construction of algorithms for supporting diagnostic processes.
    Keywords fuzzy set, multi-aspect fuzzy set, fuzzy sets similarity, fuzzy pattern of disease unit, medical diagnosis.
    Full article: PDF icon 5_11_aameljanczyk_csmm_9_2019.pdf
  2. K. Antczak - On regularization properties of artificial datasets for deep learning.
    Pages: 13 - 18
    Abstract: The paper discusses regularization properties of artificial data for deep learning. Artificial datasets allow to train neural networks in the case of a real data shortage. It is demonstrated that the artificial data generation process, described as injecting noise to high-level features, bears several similarities to existing regularization methods for deep neural networks. One can treat this property of artificial data as a kind of “deep” regularization. It is thus possible to regularize hidden layers of the network by generating the training data in a certain way..
    Keywords deep learning, regularization, artificial data.
    Full article: PDF icon 13_18_kantczak_csmm_9_2019.pdf
  3. A. Chojnacki, F. Darnowski - A model of the process of writing and deleting file information on a disk with NTFS.
    Pages: 19 - 25
    Abstract: This paper aims at demonstrating a mathematical model of the process of writing and deleting information about files on a disk, using the contents of the $MFT system file, i.e. in a file generated in the NTFS (New technology File System). The presented model uses the language of control theory, where the state of the system is equal to the state of the disk and the state of the $MFT file, and where control is understood as undertaking the action of writing or deleting. The deterministic nature of the process and its stationarity were assumed. Then, based on the transition function after its specification, we suggest constructing further inverse images of possible prior states at subsequent stages of data writing or deletion. The obtained results form the basis for the implementations developed.
    Keywords hard drive, NTFS, $MFT.
    Full article: PDF icon 19_25_achojnackifdarnowski_csmm_9_2019.pdf
  4. M. Pachnik - Methods of generating test data for carrying out the fuzzing process.
    Pages: 27 - 31
    Abstract: The article presents and compares modern methods of generating test data in the process of automatic software security testing, so called fuzz testing. The publication contains descriptions of methods used, among others, in local, network or web applications, and then compares them and evaluates their effectiveness in the process of ensuring software security. The impact of the quality of test data corpus on the effectiveness of automated security testing has been assessed.
    Keywords fuzzing, test data corpus, security vulnerabilities.
    Full article: PDF icon 27_31_mpachnik_csmm_9_2019.pdf
  5. A. Woźniak, T. Nowicki - The Problem of Effective Deployment Architecture in SOA.
    Pages: 33 - 44
    Abstract: Service Oriented Architecture is popular in many organizations. In particular, it has already deeply rooted in large corporations that need to automate entire business processes and implement them in many systems. It has a unique feature that allows unambiguously indicate service that is to realise business process step. That indication is possible to show directly in BPMN diagram. Thus, it is possible to trace which server has used resources to implement the service and how much of those resources were needed. Therefore, it is possible to build an optimization task that, with limited and unreliable resources, will determine such allocation of components to servers and such an algorithm for assigning tasks to them, so that the processes will work as well as possible. The article presents a model of such an optimization task. This model consists of four layers. The Organization Layer describes the system environment – the types and frequency of initiating business process instances. The Integration Layer describes the business processes and indicates the services that should be performed at every step. The Component Layer describes component characteristics and what services they provide. In Server Layer both: server characteristics and runtime environments necessary for the component to run are described. Finally, the optimization task and evaluation criteria are formulated.
    Keywords SOA deployment, mathematical model, system architecture optimization.
    Full article: PDF icon 33_44_tnowickiawozniak_csmm_9_2019.pdf

Computer Science and Mathematical Modelling No. 10/2019

  1. M. Cebula, P. Murawski - Design and implementation of an information system to study the repeatability of the orientation in space for medical applications
    Pages: 5 - 16
    Abstract: The aim of the study was to study the repeatability of the object’s orientation in space. During the study, a self-constructed system of 4 gyroscope and an available robot of the kuka type were used. An application allowing for comparison of research results was written and presented. The article contains individual stages of work (analytical and implementation), research results, conclusions and discussion.
    Keywords orientation in space, gyroscope, medical applications
    Full article: PDF icon 5_16_mcebula_pmurawski_design_csmm_10.pdf
  2. M. Romaldowski - The method of automatic assignment ICD codes based on semantic information
    Pages: 17 - 23
    Abstract: The paper presents the method of automatic assignment of ICD codes based on semantic information contained in clinical reports of the MIMIC-III database. It is showing the possibility of using multi-criteria optimization methods for simple classifiers fusion in a more precise classifiers complex. ICD code assignment is important in the modern hospital, more accurate automation of assigning codes will make the clinical process more efficient and can help clinicians carry out better diagnostics and effectively improve medical care systems.
    Keywords MIMIC III, ICD, TFIDF, word2vec, classification, machine learning, natural language processing, classifiers synthesis, Pareto filter
    Full article: PDF icon 17_23_mromaldowski_themethod_csmm_10.pdf
  3. C. Tran, A. Ameljańczyk - Clustering Web search results using Wikipedia resource
    Pages: 25 - 29
    Abstract: The paper presents a proposal of a new method for clustering search results. The method uses an external knowledge resource, which can be, for example, Wikipedia. Wikipedia – the largest encyclopedia, is a free and popular knowledge resource which is used to extract topics from short texts. Similarities between documents are calculated based on the similarities between these topics. After that, affinity propagation clustering algorithm is employed to cluster web search results. Proposed method is tested by AMBIENT dataset and evaluated within the experimental framework provided by a SemEval-2013 task. The paper also suggests new method to compare global performance of algorithms using multi – criteria analysis.
    Keywords affinity propagation, similarity of documents, multi-criteria assessment, Web search results, Wikipedia.
    Full article: PDF icon 25_29_ctran_aameljanczyk_clustering_csmm_10.pdf
  4. B. Szafrański, R. Bałazy - Data protection in transactional and statistical applications of databases
    Pages: 31 - 39
    Abstract: The article describes a discussion on the issue of data protection in databases. The discussion attempts to answer the question about the possibility of using a transactional database system as a system capable of data protection in a statistical database. The discussion is preceded by a reminder of the basic issues related to data protection in databases, including reminder of flow control models, access control models and the inference. The key element of the article is the analysis, based on the example of the Oracle database management system, whether data protection mechanisms in transactional databases can be effective in case of data protection in statistical databases.
    Keywords database, database system, data protection in database, flow control, inference control, statistical database, Oracle
    Full article: PDF icon 31_39_bszafranski_rbalazy_dataprotecton_csmm_10.pdf