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1

Fuzzy SQL queries in standard SQL database

Kudłacik P.

Journal of Medical Informatics & Technologies

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2016

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Vol. 25

28--37

EN

Uncertain queries are very common in many areas of human activity. The problem can be seen particularly in medicine, where expressions like ”very high”, ”low”, ”normal” are commonly used in order to describe different information. However, the most popular data repositories do not allow to form imprecise queries in order to filter information. Therefore, the paper proposes an extension to the standard SQL language allowing anybody to profit from fuzzy database using any SQL engine. The existing approaches employ different mechanisms in order to allow the user to perform fuzzy queries on a database. The most complex solutions modify the database engine itself. However, such approach is strongly bound to the modified server version and must be updated with any development of the original server. Nevertheless, there is possible to store fuzzy information using for instance columns of regular relational database. Therefore, this approach proposes extensions to the query language allowing to use fuzzy information in a query and provides a parser transforming a fuzzy query into a standard SQL. Thus, the database server version is irrelevant. The solution is provided as a module written in multi-platform Java language using popular JDBC database connection.

2

Determining valuable ranges of handwritten signature using fuzzy approach and window method

Kudłacik P., Doroz R.

Journal of Medical Informatics & Technologies

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2015

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Vol. 24

23--30

EN

The paper proposes possible improvements in signature recognition approach based on window method. The analysis focuses on a stage of window preprocessing using fuzzy sets in order to choose significant ranges of each signature. Proposed extension allows the solution to improve in two areas. First of all minimizing a number of processed windows significantly reduces computation time. Secondly, filtered signatures with valuable information about significant ranges allow the system to recognize signatures of a poor or good quality. Developed method of signature quality assessment can be used in any signature recognition system, regardless of used method of analysis. Merging the information about signature quality and choosing only important signature ranges should also improve the overall detection results, however, more examinations are needed to confirm this statement.

3

User profiling based on multiple aspects of activity in a computer system

Wesołowski T., Kudłacik P.

Journal of Medical Informatics & Technologies

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2014

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Vol. 23

121--130

EN

The paper concerns behavioral biometrics, specifically issues related to the verification of the identity of computer systems users based on user profiling. The profiling method for creating a behavioral profile based on multiple aspects of user activity in a computer system is presented. The work is devoted to the analysis of user activity in environments with a graphical user interface GUI. Mouse activity, keyboard and software usage are taken into consideration. Additionally, an attempt to intrusion detection based on the proposed profiling method and statistical measures is performed. Preliminary studies show that the proposed profiling method could be useful in detecting an intruder masquerading as an authorized user of the computer system. This article presents the preliminary research and conclusions.

4

An analysis of using triangular truth function in fuzzy reasoning based on a fuzzy truth value

Kudłacik P.

Journal of Medical Informatics & Technologies

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2013

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Vol. 22

103--110

EN

Fuzzy systems are widely used in research and applications considering complex information like gene recognition and classification. Because of the character of genetic data, the extensive knowledge bases of such systems contain complex rules described by even thousands of atomic premises. This paper presents an analysis of fuzzy reasoning based on a fuzzy truth value, presented by Baldwin. The solution is an interesting, alternative approach to fuzzy inference. Considering the Zadeh’s compositional rule of inference, the idea of Baldwin has an advantage of resolving the whole inference process within the truth space. The approach is especially convenient for systems with large number of premises in rules, like mentioned gene classification systems. Although the solution of Baldwin is characterized by significantly lower computational complexity than the full implementation of the compositional rule of inference, it is not applied in contemporary systems. Over the years different researchers proposed simplified approaches, which are easier to implement and faster. The analysis presented in this paper considers possible simplifications that could be applied to the approach of Baldwin, where facts and fuzzy truth values are described by triangular membership functions. Such assumptions open the possibility of implementation of fast Baldwin’s inference and applications even for complex genetic data. Nevertheless, the solution would preserve one of the biggest advantage, which is the fuzzy relation, in form of the truth function, between a fact and a premise, throughout the whole inference process. Other fast approaches reduce this relation to only one value.

5

Performance evaluation of Baldwin's fuzzy reasoning for large knowledge bases

Kudłacik P.

Journal of Medical Informatics & Technologies

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2012

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Vol. 20

29--38

EN

The paper compares performance of Baldwin's fuzzy reasoning based on a fuzzy truth value with the fastest available solutions. The analysis is important in order to locate areas where improvement of the first is the most significant. Potential fast approach based on the fuzzy truth value would be very interesting for many users applying fuzzy systems to solve problems involved with complex knowledge bases. Particularly, all research considering an analysis of genes employing DNA microarrays. Such methods very often generate rules with thousands of atomic premises. The most valuable advantage of Baldwin's reasoning is preserving a fuzzy relation between a fact and a premise in the inference process, where other solutions, especially those commonly used, usually reduce it to only one value. Obtaining the method which, from computation time point of view, is comparable with common approaches but offers more advanced process of fuzzy reasoning, would be a significant achievement. The goal of this analysis is to prepare the future research considering development of Baldwin's method, which computational complexity is comparable to simple, fast and widely used solutions like systems based on the approach of Mamdani and Assilan or Larsen.

6

Improving a signature recognition method using the fuzzy approach

Kudłacik P.

Journal of Medical Informatics & Technologies

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2012

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Vol. 21

85--93

EN

The paper introduces a significant improvement of the signature recognition method based on characteristic preprocessing of an input data. The original approach transforms an input data into a sorted set of points obtained from intersections of a signature with generated lines going through it's center point. For further analysis the discrete Walsh transform was used. The solution presented in this paper divides points obtained in the preprocessing phase into groups. This step allows the method to preserve more unique features, which positively reflects on the results. Preprocessed data is used to build a fuzzy structure called the fuzzy signature. The method considering a natural imprecision makes the verification system flexible.

7

Struktura bazy wiedzy w bibliotece FUZZLIB

Kudłacik P.

Studia Informatica

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2010

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Vol. 31, nr 2A

469-478

PL

Biblioteka FUZZLIB to zbiór narzędzi pozwalających tworzyć i zarządzać rożnymi systemami rozmytymi za pomocą prostego w użyciu interfejsu. Szczególnie ułatwiono konfigurację i zarządzanie regułowej bazy wiedzy opartej na strukturach dynamicznych. Niniejszy artykuł opisuje zastosowane rozwiązania oraz interfejs programistyczny.

EN

FUZZLIB library provide a set of tools that let to create and manage diverse fuzzy systems with an easy to use interface. Configuration and management of a rule base, based on dynamic structures, is especially simplified. Article describes developed solutions and program interface.

8

Advantages of an approximate reasoning based on a fuzzy truth value

Kudłacik P.

Journal of Medical Informatics & Technologies

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2010

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Vol. 16

125--131

EN

The approximate reasoning based on a fuzzy truth value is based on a different view of linguistic statements and comparing with the compositional rule of inference has some advantages. Benefits of the method are especially important for fuzzy expert systems with large sets of premises. The problem is very common for many applications in medicine, biology and biometry. By a short analysis of the approach and comparing to the compositional rule of inference the paper emphasizes the most important advantages of a possible implementation, which is particularly significant for the mentioned fields.

9

Trwałe przechwytywanie elementów graficznego interfejsu użytkownika

Kudłacik P., Wesołowski T.

Studia Informatica

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2008

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Vol. 29, nr 2A

69-77

PL

Artykuł przedstawia mechanizm pobierania danych wskazanych elementów graficznego interfejsu użytkownika oraz metodę ponownego ich zlokalizowania bez względu na instancję aplikacji. Mechanizm nazwano trwałym przechwytywaniem elementów GUI . Podczas realizacji założono wykorzystanie jedynie funkcji API systemu operacyjnego Windows. Działanie przetestowano na interfejsach graficznych aplikacji systemu Windows oraz platform .NET i Java.

EN

Paper presents a mechanism of collecting data of graphical user interface elements pointed by user as well as method of searching based on collected data. The mechanism was called a permanent capture of GUI elements because it allows to find pointed element independently on application's instance. Task implementation assumed usage of API functions available in Windows operating system without additional, external libraries. Solution was tested with Windows applications as well as .NET and Java platforms.

10

Operacje na zbiorach rozmytych z odcinkowo-liniową funkcją przynależności

Kudłacik P.

Studia Informatica

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2008

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Vol. 29, nr 3A

91-111

PL

Artykuł zawiera szczegółowy opis algorytmów realizujących podstawowe operacje na zbiorach rozmytych z odcinkowo-liniową funkcją przy-należności. Funkcja przynależności zbioru reprezentowana jest za pomocą wektora zawierającego kolejne punkty jej opisu. Przedstawione operacje obejmują wyznaczanie wartości przynależności danego elementu zbioru, rozmywanie, wyostrzanie oraz operacje na większej ilości zbiorów, jak suma, przecięcie i agregacja.

EN

Paper presents precise description of algorithms for basic operations on fuzzy sets with piecewise linear membership function. Membership function is represented with vector storing subsequent points of function's description. Presented algorithms concern operations like calculating a membership value for given element, fuzzyfication, defuzzyfication as well as operations on more than one fuzzy sets like intersection, union and aggregation.