2014 - Publications Repository - Gdańsk University of Technology

Show publications from the year

Publications from the year 2014

Show all

On simplification of residue scaling process in pipelined Radix-4 MQRNS FFT processor
- Robert Smyk
- Maciej Czyżak
2014 Computer Applications in Electrical Engineering
Residue scaling is needed in pipelined FFT radix-4 processors based on the Modified Quadratic Residue Number System (MQRNS) at the output of each butterfly. Such processor uses serial connection of radix-4 butterflies. Each butterfly comprises n subunits, one for each modulus of the RNS base and generates four complex residue numbers. In order to prevent arithmetic overflow intermediate results after each butterfly have to be scaled, i.e. divided by a certain constant. The number range of the processed signal increases due to transformation of coefficients of the FFT algorithm to integers and summation and multiplication within the butterfly. The direct approach would require eight residue scalers that would be highly ineffective regarding that such a set of scalers had to be placed after each butterfly. We show and analyze a structure which uses parallel-to-serial transformation of groups of numbers so that only two residue scalers are needed.
On Software Unit Testing For Improving Security And Performance Of Distributed Applications
- Henryk Krawczyk
- Marcin Barylski
- Adam Barylski
2014 Key Engineering Materials
Performance and security are software (SW) application attributes situated on the opposite corners of system design. In the most drastic example the most secure component is the one totally isolated from the outside world, with communication performance reduced to zero level (e.g. disconnected physically from the network, placed inside a Faraday cage to eliminate possible wireless accessibility). On the other hand the most performance-optimized system is the one with all security rules taken off. Obviously such extreme implementations cannot be accepted, thus a reasonable trade-off between security and performance is desired, starting from the appropriate design, resulting in the adequate implementation, confirmed by security and performance testing in production environment. Unit Testing (UT) is a well-know method of examining the smallest portion of SW application source code – units: methods, classes, interfaces in order to verify whether they behave as designed. Ideally, each UT test case is separated from others, taking advantage of stubs and mocks to provide full isolation from external test factors. This paper is an extension to research about joint security testing and performance testing for improving quality of distributed applications working in public-private network environments, addressing SW quality assessment at different, unit test level.
On Symmetry of Uniform and Preferential Attachment Graphs
- Abram Magner
- Svante Janson
- Giorgos Kollias
- Wojciech Szpankowski
2014 Full text ELECTRONIC JOURNAL OF COMBINATORICS
Motivated by the problem of graph structure compression under realistic source models, we study the symmetry behavior of preferential and uniform attachment graphs. These are two dynamic models of network growth in which new nodes attach to a constant number m of existing ones according to some attachment scheme. We prove symmetry results for m=1 and 2 , and we conjecture that for m≥3 , both models yield asymmetry with high probability. We provide new empirical evidence in terms of graph defect. We also prove that vertex defects in the uniform attachment model grow at most logarithmically with graph size, then use this to prove a weak asymmetry result for all values of m in the uniform attachment model. Finally, we introduce a natural variation of the two models that incorporates preference of new nodes for nodes of a similar age, and we show that the change introduces symmetry for all values of m.
On the convergence of a finite-difference discretization à la Mickens of the generalized Burgers–Huxley equation
- Anna Szafrańska
- J. E. Macías-Díaz
2014 JOURNAL OF DIFFERENCE EQUATIONS AND APPLICATIONS
In this note, we establish the property of convergence for a finite-difference discretization of a diffusive partial differential equation with generalized Burgers convective law and generalized Hodgkin–Huxley reaction. The numerical method was previously investigated in the literature and, amongst other features of interest, it is a fast and nonlinear technique that is capable of preserving positivity, boundedness and monotonicity. In the present work, we establish that the method is convergent with linear order of convergence in time and quadratic order in space. Some numerical experiments are provided in order to support the analytical results.
On the Limiting distribution of Lempel Ziv'78 Redundancy for Memoryles Sources
- Philippe Jacquet
- Wojciech Szpankowski
2014
We show that the Lempel Ziv'78 redundancy rate tends to a Gaussian distribution for memoryless sources. We accomplish it by extending findings from our 1995 paper [3]. We present a new simplified proof of the Central Limit Theorem for the number of phrases in the LZ'78 algorithm. As in our 1995 paper, here we first analyze the asymptotic behavior of the total path length in a digital search tree (a DST) built from independent sequences. Then we present simplified proofs and extend our analysis of LZ'78 algorithm to include new results on the convergence of moments, moderate and large deviations, and redundancy analysis.
On the Limiting Distribution of Lempel-Ziv’78 Redundancy for Memoryless Sources
- Philippe Jacquet
- Wojciech Szpankowski
2014 IEEE TRANSACTIONS ON INFORMATION THEORY
We study the Lempel-Ziv'78 algorithm and show that its (normalized) redundancy rate tends to a Gaussian distribution for memoryless sources. We accomplish it by extending findings from our 1995 paper, in particular, by presenting a new simplified proof of the central limit theorem (CLT) for the number of phrases in the LZ'78 algorithm. We first analyze the asymptotic behavior of the total path length in the associated digital search tree built from independent sequences. Then, a renewal theory type argument yields CLT for LZ'78 scheme. Here, we extend our analysis of LZ'78 algorithm to present new results on the convergence of moments, moderate and large deviations, and CLT for the (normalized) redundancy. In particular, we confirm that the average redundancy rate decays as 1/log n, and we find that the variance is of order 1/n, where n is the length of the text.
On the partition dimension of trees
- Juan Alberto Rodriguez-Velazguez
- Ismael Gonzalez Yero
- Magdalena Lemańska
2014 Full text DISCRETE APPLIED MATHEMATICS
Given an ordered partition Π={P1,P2,…,Pt} of the vertex set V of a connected graph G=(V,E), the partition representation of a vertex v∈V with respect to the partition Π is the vector r(v|Π)=(d(v,P1),d(v,P2),…,d(v,Pt)), where d(v,Pi) represents the distance between the vertex vv and the set Pi. A partition Π of V is a resolving partition of G if different vertices of G have different partition representations, i.e., for every pair of vertices u,v∈V, r(u|Π)≠r(v|Π). The partition dimension of G is the minimum number of sets in any resolving partition of G. In this paper we obtain several tight bounds on the partition dimension of trees.
On the Peano Theorem for Some Functional Differential Equations on Time Scale
- Antoni Augustynowicz
- Agata Gołaszewska
2014 Functional Differential Equations
The Peano Theorem for some functional differential equations on time scale is proved. Assumptions are of Caratheodory type. Two counter examples for false Peano theorems in the literature are presented.
OpenGL accelerated method of the material matrix generation for FDTD simulations
- Sławomir Orłowski
- Tomasz Stefański
2014
This paper presents the accelerated technique of the material matrix generation from CAD models utilized by the finite-difference time-domain (FDTD) simulators. To achieve high performance of these computations, the parallel-processing power of a graphics processing unit was employed with the use of the OpenGL library. The method was integrated with the developed FDTD solver, providing approximately five-fold speedup of the material matrix generation in comparison to the solution executed on a central processing unit.
Operating system security by integrity checking and recovery using write-protected storage
- Jerzy Kaczmarek
- Michał Wróbel
2014 Full text IET Information Security
The paper presents an Integrity Checking and Recovery (ICAR) system which protects file system integrity and automatically restores modified files. The system enables files cryptographic hashes generation and verification, as well as configuration of security constraints. All of the crucial data, including ICAR system binaries, file backups and hashes database are stored in a physically write protected storage to eliminate the threat of unauthorized modification. A buffering mechanism was designed and implemented in the system to increase operation performance. Additionally, the system supplies user tools for cryptographic hash generation and security database management. The system is implemented as a kernel extension, compliant with the Linux Security Model. Experimental evaluation of the system was performed and showed an approximate 10% performance degradation in secured file access compared to regular access.
Operation of the 900 MW power plant with the ORC supplied from three heat sources
- Dariusz Mikielewicz
- Łukasz Bartela
- Piotr Ziółkowski
- Jan Wajs
- Jarosław Mikielewicz
2014
The chapter is aimed at utilisation of waste heat in the reference supercritical power plant in the manner to produce electricity in ORC installation. The waste heat is available in the form of a stream of hot water at 90°C, recovered from the exhaust gases in the amount of 200MW. Such low enthalpy heat source is rather insufficient to produce a good quality vapour to feed the ORC turbine. Therefore an original approach to increase temperature of the vapour of ORC working fluid at the inlet to the turbine has been proposed through the use of heat from the bleed steam from the low-pressure part of the steam turbine of the reference power plant. Additionally the system uses heat from the CO2 capture installation. Analysis was accomplished using the Aspen Plus numerical code. Investigated were four working fluids such as pentane, ethanol, R236ea and R245fa. All fluids rendered the increase of the unit power and efficiency, however the conclusion is that not always the fluid having highest thermal efficiency is capable of producing the highest power.
Opinia do koncepcji architektonicznej pn. „Przebudowa dworca kolejowego Gdańsk Główny” (Departament Inwestycji Zespół ds. projektowania w Gdańsku Polskie Koleje Państwowe S.A., lipiec 2014)
- Daniel Załuski
2014
Ocena funkcjonalno-przestrzenna koncepcji architektonicznej pn. „Przebudowa dworca kolejowego Gdańsk Główny” wykonanej przez Departament Inwestycji Zespół ds. projektowania w Gdańsku Polskie Koleje Państwowe S.A., lipiec 2014
Opinia dotycząca stanu mieszadeł komór fermentacyjnych oczyszczalni ścieków Gdańsk-Wschod
- Jerzy Stuczyński
- Krzysztof Krzysztofowicz
2014
Dokonano oględzin i oceny stanu mieszadła zbiornika 15/3.
Opinia ekspercka w zakresie ustalenia przyczyn powstania ujawnionej wady kolektora zrealizowanego w ramach zadania inwestycyjnego „Budowa kanalizacji sanitarnej w miejscowości Rozwadza wraz z tranzytem do oczyszczalni ścieków w Zdzieszowicach, pompownie P1 i P2 Rozwadza”
- Ziemowit Suligowski
2014
Analiza przyczyn i konsekwencji zaistniałej awarii nowo budowanego kolektora. Ocena przebiegu procesu inwestycyjnego. Braki formalne - zawodowe uczestników procesu, braki w dokumentacji. Problem niewłaściwej oceny warunków posadowienia kanału w dokumentacji projektowej. Błędy kierownika budowy. Negatywna ocena propozycji rozwiązania problemów. Wnioski dotyczące kierunku rozwiązania.
Opinia geotechniczna dotycząca projektu budowlanego Ocena rozwiązań konstrukcyjnych elementów posadowienia obiektów inżynierskich w ciągu drogi ekspresowej S7 na odcinku Koszwały – Kazimierzowo
- Kazimierz Gwizdała
- Adam Krasiński
- Paweł Więcławski
- Andrzej Słabek
2014
Przedmiotem opracowania jest ocena rozwiązań posadowienia obiektów inżynierskich w ciągu drogi ekspresowej S7 na odcinku Koszwały – Kazimierzowo, przedstawionych przez Transprojekt Gdański Sp. z o.o., ul. Partyzantów 72A, 80-254 Gdańsk. Weryfikacja obejmuje: Zadanie 1: Koszwały– Nowy Dwór Gdański; Zadanie 2: Nowy Dwór Gdański – Kazimierzowo
Opinia na okoliczność wykonania (prawidłowego lub nie, w części lub całości ) umowy 01/11/2010 dotyczącej remontu statku m/v „AKERO” w sprawie z powództwa Quadrant Marine Consultancy Sp. z o.o. przeciwko Northwind Shipping A.S. w Enebakk, Norwegia
- Zbigniew Górski
- Jakub Kowalski
- Janusz Kozak
2014
Opinia na temat prawidłowości (nieprawidłowości) przebiegu remontu statku M/V Akero (później M/V North Wind), wydana na zlecenie Sądu Okręgowego w Gdańsku. Opinię sporządzono na podstawie akt sprawy IXGC 14/12.
Opinia o innowacyjności - Wzrost konkurencyjności przedsiębiorstwa ZPHU TEMIROL poprzez zakup innowacyjnej maszyny do obróbki plastycznej blach
- Jerzy Łabanowski
2014
Wykonano opinię o innowacyjności dotyczącą prasy krawędziowej TOSKAR EASYFAB 2600/120 wyposażonej w sterownik Next dedykowanej do precyzyjnego gięcia blach do grubości 6 mm
Opinia o innowacyjności dotycząca Projektu: "Wdrożenie innowacyjnej technologii obróbki obejm łożyskowych oraz innych komponentów dla elektrowni wiatrowych"
- Wojciech Blacharski
2014
Opinia o innowacyjności opracowana dla projektu przygotowanego przez Przedsiębiorstwo Produkcyjno Usługowe METALMOR SP.J. w ramach Regionalnego Programu Operacyjnego Województwa Warmińsko-Mazurskiego 2007-2013, działanie 1.1.7. - Dotacje inwestycyjne dla mikroprzedsiębiorstw i sektora MŚP w zakresie innowacji i nowych technologii, na temat: "Wdrożenie innowacyjnej technologii obróbki obejm łożyskowych oraz innych komponentów elektrowni wiatrowych".
Opinia o innowacyjności pt. "Innowacyjny przenośny skaner terahercowy o szerokim spektrum zastosowań
- Sławomir Gajewski
- Małgorzata Gajewska
2014
Wydano ekspertyzę o innowacyjności przenośnego skanera terahercowego o szerokim spektrum zastosowań
Opinia o innowacyjności; Wdrożenie technologii spawania stali duplex w połączonej metodzie rulonowej i swobodnego podparcia.
- Dariusz Fydrych
2014
Opinia dotyczy nowego sposobu wykonania cylindrycznego zbiornika stalowego o dużych wymiarach, co stanowi ulepszenie znanej techniki wytwarzania zbiorników metodą podbudowy dolnych pierścieni od dachu w dół z zastosowaniem tzw. swobodnego podparcia.