Tytuł: The autonomous navigation system of a sea-going vessel

Autor/Autorzy: Pietrzykowski Z., Wołejsza P., Nozdrzykowski Ł., Borkowski P., Banaś P., Magaj P., Chomski J., Mąka M., Mielniczuk S., Pańka A., Hatłas - Sowińska P., Kulbiej E., Nozdrzykowska M.

Miejsce publikacji: Ocean Engineering (2022), 261, art.. No.112104

Rok: 2022

Słowa kluczowe: Autonomous navigation; Automatic communication; Collision avoidance; Maritime autonomous surface ship; Unmanned aerial vehicle

Abstrakt: We propose an integrated comprehensive system of an Autonomous Surface Vessel (ASV), dedicated to ships with various degrees of autonomy. The system performs a variety of tasks aimed at safe voyage execution. The use of basic and additional information sources is envisaged, including data from unmanned remotely controlled and autonomous aerial vehicles, to increase situational awareness. After defining the assumptions and devising the architecture of the system, we built its model. The key elements of the model, collision avoidance and automatic communication modules, are capable of developing and agreeing on manoeuvres between autonomous vessels in the negotiation process. The model was implemented as a real time system and verified in three stages: laboratory tests, quasi-real tests using physical models of ships and in real operational conditions on board ships at sea. The research results have confirmed the correctness of the assumptions, designed system architecture and developed algorithms.

Tytuł: Method of Visual Detection of the Horizon Line and Detection Assessment for Control Systems of Autonomous and Semi-autonomous Ships

Autor/Autorzy: Łukasz Nozdrzykowski, Magdalena Nozdrzykowska

Miejsce publikacji: Theory and Engineering of Dependable Computer Systems and Networks. DepCoS-RELCOMEX 2021. Advances in Intelligent Systems and Computing, vol 1389. Springer, Cham, pp. 326-338

Rok: 2021

Słowa kluczowe: Horizon line detection, Autonomous ships, Filtering and statistical methods, Machine vision, Image processing,

Abstrakt: Autonomous and semiautonomous ships need visual systems for the identification of the horizon line and recognition of invisible obstacles on electronic charts or the radar - positioning and identification of other objects. Varying observation conditions are a major disadvantage in such systems, as they are related to the accuracy of horizon detection. The proposed method of horizon detection for varied observation conditions is based on a combination of selected filtrations and statistical calculations. The method enables the identification of a horizon line in difficult conditions of observation, e.g. clouded sky or sunset. The development of the method for horizon line identification was preceded by an analysis of strengths and weaknesses of relevant digital image processing methods. The novelties of the method include: 1) development of a method for assessing how useful an acquired image is in horizon line detection; 2) automating the acquisition of parameters used in proposed algorithms of image processing; 3) selection of algorithms for line detection for optimized speed of computing and reliability of the process. The proposed method combines filtration and statistical methods. As a result, the system detects the horizon in any observation conditions reliably and fast. This property is important for an autonomous system that must respond to events in real time, including sudden appearance of an obstruction.

Tytuł: Building of a Variable Context Key Enhancing the Security of Steganographic Algorithms

Autor/Autorzy: Magdalena Nozdrzykowska, Łukasz Nozdrzykowski

Miejsce publikacji: Theory and Engineering of Dependable Computer Systems and Networks. DepCoS-RELCOMEX 2021. Advances in Intelligent Systems and Computing, vol 1389. Springer, Cham. pp.316-325

Rok: 2021

Słowa kluczowe: Steganography, Data protection, Context key, Security in mobile systems, Variable steganographic key

Abstrakt: This article presents a concept of a context key for steganographic algorithms. The proposed scheme of building the context key is designed to enhance the level of security of the applied algorithm. Reading a hidden message should be possible when certain requirements defined as the context are met. For example, such requirements include a specific level of lighting, location and a password protected access, while typing the password itself can be arranged to require appropriate context. This may be characterized by the speed of typing the characters etc. Therefore, the context key will be used in mobile devices such as a smartphone, tablet, etc. The context key building scheme has been proposed, allowing the key to be changed at any stage of the hiding algorithm. The proposed solution protects subsequent bits of a hidden message against retrieving or forward inference, which means that a key broken at a certain stage does not allow concluding what key will be used in the next algorithm step and what key was used previously. In addition, the presented key scheme allows reading a message while the context is not fully met.

The authors aimed to propose the possibility of using the context key as a type of strengthening the security of steganographic algorithms by adding new elements blocking the possibility of reading messages by unauthorized persons. The possibilities offered by sensors in mobile devices were used for this purpose. The novelty in the proposed key is the use of threshold methods of sharing secrets as a mechanism enabling the user to read a message even if not all environmental conditions are satisfied during the reading of the secured message.

Tytuł monografii: Advances in Dependability Engineering of Complex Systems

Tytuł rozdziału monografii: Testing the Significance of Parameters of Models Estimating Execution Time of Parallel Program loops According to the Open MPI Standard

Autor/Autorzy: Łukasz Nozdrzykowski, Magdalena Nozdrzykowska

Rok: 2018

Słowa kluczowe: program loops, time stimation, significance analysis, Rough set theory

Abstrakt: The authors present their own models for estimating the execution time of program loops in parallel systems with message transmission (Open MPI) along with an analysis of the significance of the parameters used for the estimation and for proving the correctness of these models, which is the main goal of this article. The significance analysis proposed by the authors of the models was based on measurements of actual performance of test loops from the NAS Parallel Benchmarks, which provides sets of test loops in the field of numerical problem solving. By applying the significance analysis, we demonstrate the accuracy of selected parameters as relevant parameters of the presented models. The significance analysis was based on soft reduction of conditional attributes using the relative probability of rules useful in the theory of rough sets.

ISBN: 978-3-319-59414-9

Tytuł: Modele szacowania czasów wykonywania się pętli programowych z wykorzystaniem programowania równoległego na CPU oraz z wykorzystaniem obliczeń na GPU przy użyciu OpenCl

Autor/Autorzy: Łukasz Nozdrzykowski, Magdalena Nozdrzykowska

Miejsce publikacji: Autobusy. Technika, Eksploatacja, Systemy Transportowe, vol. 226, no. 12, pp. 802-807

Rok: 2018

Słowa kluczowe: pętle programowe, szacowanie czasu wykonania pętli, programowanie CPU i GPGPU, programming loop, estimating the time of the loop, programming CPU and GPGPU

Abstrakt: W artykule autorzy przedstawiają modele szacowania czasów wykonywania się pętli programowych zgodnych z modelem FAN nieposiadającym zależności lub posiadającym zależności, ale tylko w ciele pętli, które wykonywane mogą być przez centralne jednostki obliczeniowe CPU jak i multiprocesory strumieniowe zwane rdzeniami kart graficznych GPU. Zaprezentowane w niniejszym artykule modele szacowania czasów wykonywania tych pętli pozwolą na określanie tego, czy obliczenia w zastanym środowisku obliczeniowym warto wykonywać z użyciem posiadanego procesora CPU czy korzystniejsze będzie wykorzystanie do obliczeń posiadanej, często nowoczesnej, karty graficznej z wydajną jednostką GPU i bardzo szybką pamięcią stosowaną we współczesnych kartach graficznych. Wraz z zaprezentowanymi modelami przedstawiono także testy potwierdzające poprawność opracowanych modeli szacowania czasu. Celem powstania tych modeli jest dostarczenie metod przyspieszania działania aplikacji realizujących różne zadania, w tym zadania transportowe, takie jak przyspieszone przeszukiwanie rozwiązań, przeszukiwanie ścieżek w grafach, czy przyspieszanie algorytmów przetwarzania obrazów w systemach wizyjnych pojazdów autonomicznych i semiautonomicznych, przy czym modele te pozwalają na zbudowanie systemu automatycznego rozdzielania zadań pomiędzy CPU i GPU przy zmienności zasobów obliczeniowych.

Tytuł: Implementation of the attribute significance analysis with the use of soft reduction of attributes in the rough set theory on the basis of the SQL mechanisms

Autor/Autorzy: Łukasz Nozdrzykowski, Magdalena Nozdrzykowska

Miejsce publikacji: Measurement Automation Monitoring - Pomiary Automatyka Kontrola, vol. 63, no. 1, pp. 10-14

Rok: 2017

Słowa kluczowe: rough set theory, data analysis, soft reduction of attributes, SQL implementation

Abstrakt: This article presents a way to use databases supporting the SQL and PL/SQL in the implementation of a method of attribute significance analysis with the use of soft reduction of attributes in the rough set theory. A number of SQL queries are presented, which facilitate the implementation. The original mechanisms presented previously [1] are supplemented with queries which facilitate the execution of attribute coding. The authors present a complete implementation of the method, from the coding of attributes to the determination of the significance of conditional attributes. Application of queries to the database eliminates the necessity to build data grouping and data mining mechanisms and calculation of repetitions of identical rules in the reduced decision rule space. Without the support of a database, the creation of universal data grouping and data mining mechanisms which could be used with any number of attributes is a challenging task