Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 15
items per page: 25 50 75
Sort by:
Download PDF Download RIS Download Bibtex

Abstract

The hereby paper discusses the influence of cable length on the SHM systems with the use of vibrating wire dynamic measurements. Vibrating wire sensors are mainly used for measuring stable or slowly changing strains, e.g. system installed on Rędziński Bridge in Wroclaw. From some time applications of these sensors for measuring dynamic deformations are becoming popular. Such tests were conducted on STS Fryderyk Chopin. New solutions generate new problems. In this case: the operational stability of systems exciting wire vibrations. The structure of such sensors and the electric cables length has an essential influence on their operations, what is undertaken in the paper. The subject of investigations constitutes the measuring system based on self-exciting impulse exciter, for which impedance parameters of electric cables and of the vibrating wire sensor were the most essential. The mathematical model of the system, experimental verification of the model as well as the results of theoretical analyses at the application of electric cables of various lengths are presented in the paper.

Go to article

Authors and Affiliations

G. Cieplok
W. Karwowski
Ł. Bednarski
Download PDF Download RIS Download Bibtex

Abstract

The paper presents results of the laboratory tests made for the prototype resilient under sleeper pads in the Warsaw University of Technology laboratory unit. These pads are dedicated to reduce vibrations transmitted to the vicinity of the railroad and to improve the resistance of the railroad structure. The laboratory testing program was carried out for elastomeric materials (polyurethane and rubber based) due to the PN-EN 16730 standard. The obtained values of the key parameters were used in order to determine the insertion loss vibration level by applying analytical method. The paper presents the influence of selected parameters i.e. static and dynamic moduli on the reduction of vibration and structure-borne sound level.

Go to article

Authors and Affiliations

C. Kraśkiewicz
A. Zbiciak
W. Oleksiewicz
W. Karwowski
Download PDF Download RIS Download Bibtex

Abstract

Czym są nieprawdziwe informacje w internecie i jak naukowcy z nimi walczą?
Go to article

Authors and Affiliations

Piotr Karwowski
Download PDF Download RIS Download Bibtex

Abstract

P.F. Strawson and J.L. Austin approach the problem of other minds from different perspectives. Peter Strawson looks at this problem from the perspective of descriptive metaphysics, which largely disregards the concrete situations in which we use mental language. John Austin, on the other hand, believes that to understand what is happening in such situations holds the key to solving the former problem. However, as it turns out, the considerations of both authors in the key fragments rely on similar observations. In addition, Austin’s perspective, which looks at the language from the point of view of its usage, makes it possible to formulate an answer to the Strawson’s critics. This does not exclude the possibility of agreeing with Strawson on the primacy of the reference function of language, if we understand it properly. Ultimately, Strawson and Austin’s approaches do not compete, but complement each other.

Go to article

Authors and Affiliations

Mateusz Karwowski
Download PDF Download RIS Download Bibtex

Abstract

Most philosophers believe that a unified philosophical account of mental and non -mental actions is possible. This article presents two arguments indicating that in fact it is not possible. The first one says that thinking is not an activity. Its formulation, however, is exposed to significant difficulties. The second argument avoids these difficulties and puts forward a different, though sometimes erroneously identified, thesis that mental and non-mental actions differ significantly, and therefore one theory should not be expected to include both phenomena. Acceptance of this result sheds new light on the problems associated with the language of thought and gives promise to a new answer to the question “What is Le Penseur doing?”

Go to article

Authors and Affiliations

Mateusz Karwowski
Download PDF Download RIS Download Bibtex

Abstract

The paper presents Improved Adaptive Arithmetic Coding algorithm for application in future video compression technology. The proposed solution is based on the Context-based Adaptive Binary Arithmetic Coding (CABAC) technique and uses the authors mechanism of symbols probability estimation that exploits Context-Tree Weighting (CTW) technique. This paper proposes the version of the algorithm, that allows an arbitrary selection of depth D of context trees, when activating the algorithm in the framework of the AVC or HEVC video encoders. The algorithm has been tested in terms of coding efficiency of data and its computational complexity. Results showed, that depending on depth of context trees from 0.1% to 0.86% reduction of bitrate is achieved, when using the algorithm in the HEVC video encoder and 0.4% to 2.3% compression gain in the case of the AVC. The new solution increases complexity of entropy encoder itself, however, this does not cause an increase of the complexity of the whole video encoder.
Go to article

Authors and Affiliations

Damian Karwowski
Marek Domański
Download PDF Download RIS Download Bibtex

Abstract

Management and Production Engineering Review (MPER) is a peer-refereed, international, multidisciplinary journal covering a broad spectrum of topics in production engineering and management. Production engineering is a currently developing stream of science encompassing planning, design, implementation and management of production and logistic systems. Orientation towards human resources factor differentiates production engineering from other technical disciplines. The journal aims to advance the theoretical and applied knowledge of this rapidly evolving field, with a special focus on production management, organisation of production processes, management of production knowledge, computer integrated management of production flow, enterprise effectiveness, maintainability and sustainable manufacturing, productivity and organisation, forecasting, modelling and simulation, decision making systems, project management, innovation management and technology transfer, quality engineering and safety at work, supply chain optimization and logistics. Management and Production Engineering Review is published under the auspices of the Polish Academy of Sciences Committee on Production Engineering and Polish Association for Production Management. The main purpose of Management and Production Engineering Review is to publish the results of cutting-edge research advancing the concepts, theories and implementation of novel solutions in modern manufacturing. Papers presenting original research results related to production engineering and management education are also welcomed. We welcome original papers written in English. The Journal also publishes technical briefs, discussions of previously published papers, book reviews, and editorials. Letters to the Editor-in-Chief are highly encouraged.
Go to article

Authors and Affiliations

Tareq Z. Ahram
Waldemar Karwowski
Download PDF Download RIS Download Bibtex

Abstract

On the 14th of February, 2015, a huge fire broke out on Łazienkowski Bridge; a five span bridge, 423 m long and 28 m wide, built in the years 1972-74. It was a fully steel structure with four plate girders and orthotropic deck. The fire started under the first span during the replacement of wooden service decks. The next day, the Department of Bridges of the Warsaw University of Technology was designated to conduct an expertise material investigation, geometrical verification, and FEM model analysis. The subject of this paper concentrates on geometrical issues. The main difficulty of this task was the lack of full reference data regarding the bridge's original structure. The old design was incomplete and there was no actual surveying results for the undamaged structure. As a conclusion, some remarks focused on surveying measurements and on the final decision regarding this bridge are given. It was eventually exchanged into a brand new one and put into public use on the 28th of October, 2015.

Go to article

Authors and Affiliations

H. Zobel
W. Karwowski
M. Wróbel
P. Mossakowski
Download PDF Download RIS Download Bibtex

Abstract

Optimization of encoding process in video compression is an important research problem, especially in the case of modern, sophisticated compression technologies. In this paper, we consider HEVC, for which a novel method for selection of the encoding modes is proposed. By the encoding modes we mean e.g. coding block structure, prediction types and motion vectors. The proposed selection is done basing on noise-reduced version of the input sequence, while the information about the video itself, e.g. transform coefficients, is coded basing on the unaltered input. The proposed method involves encoding of two versions of the input sequence. Further, we show realization proving that the complexity is only negligibly higher than complexity of a single encoding. The proposal has been implemented in HEVC reference software from MPEG and tested experimentally. The results show that the proposal provides up to 1.5% bitrate reduction while preserving the same quality of a decoded video.
Go to article

Authors and Affiliations

Olgierd Stankiewicz
Krzysztof Wegner
Damian Karwowski
Jakub Stankowski
Krzysztof Klimaszewski
Tomasz Grajek

This page uses 'cookies'. Learn more