2014 - Repozytorium publikacji - Politechnika Gdańska

Pokaż publikacje z roku

Publikacje z roku 2014

Pokaż wszystkie

Design space reduction and variable-fidelity EM simulations for feasible Pareto optimization of antennas
- Adrian Bekasiewicz
- Sławomir Kozieł
- Włodzimierz Zieniutycz
2014
A computationally efficient procedure for multi-objective optimization of antenna structures is presented. In our approach, a response surface approximation (RSA) model created from sampled coarse-discretization EM antenna simulations is utilized to yield an initial set of Pareto-optimal designs using a multi-objective evolutionary algorithm. The final Pareto front representation for the high-fidelity model is obtained using surrogate-based optimization techniques. A critical stage of the design process is an initial reduction of the design space aimed at estimating the region containing the Pareto set, which allows for low-cost construction of the RSA model even if the number of designable parameters is large. Illustration example is provided. An importance of the design space reduction is also demonstrated.
Design Space Reduction for Expedited Multi-Objective Design Optimization of Antennas in Highly-Dimensional Spaces
- Adrian Bekasiewicz
- Sławomir Kozieł
- Włodzimierz Zieniutycz
2014
A surrogate-based technique for efficient multi-objective antenna optimization is discussed. Our approach exploits response surface approximation (RSA) model constructed from low-fidelity antenna model data (here, obtained through coarse-discretization electromagnetic simulations). The RSA model enables fast determination of the best available trade-offs between conflicting design goals. The cost of RSA model construction for multi-parameter antennas is significantly lowered through initial design space reduction. Optimization of the response surface approximation model is carried out by a multi-objective evolutionary algorithm. Additional response correction techniques are subsequently applied to improve selected designs at the level of high-fidelity electromagnetic antenna model. The refined designs constitute the final Pareto set representation. The pre-sented multi-objective design approach is validated using three examples: a six-variable ultra-wideband dipole antenna, an eight-variable planar Yagi-Uda anten-na and an ultra-wideband monocone with thirteen design variables.
Design thinking qualifications framework – standardizing the innovative approach to entrepreneurial education delivery to engineering students
- Joanna Szustakiewicz
2014
Highly competitive labor market stimulates increasing expectations towards fresh university alumni. It is not enough to be an expert - well educated and often experienced - in chosen discipline. High variability of the business environment, continuous change, number of risks, together with higher work demand than supply, shape clear employers’ expectations: entrepreneurial employees are wanted. On this ground a need for entrepreneurial education arises to be promptly delivered to engineering schools. Polish Academia for years continues implementing different methodologies and approaches. One of the most recent, introduces design thinking and incorporates it into teaching curricula of the leading technology universities in Poland. This article reflects on design thinking as a vehicle for introduction of entrepreneurial mindset to engineers. Its main value lies in discussion of design thinking teaching outcomes within the qualifications framework. It implies that introduction of design thinking to engineering studies curricula may be universities’ expressway in delivering highly specialized and at the same time entrepreneurial employees to the labor market.
Designate of CTOD for WM and HAZ, report no: WOiO/II/122/2014
- Jakub Kowalski
- Lech Nadolny
- Andrzej Wołoszyn
- Marek Kula
2014
Typical (normative) testing of materials and/or welded joints do not answer on all questions about material or welded joint properties. In ship building and off-shore sectors, many strucures requires materials and joint with higher than typical fatigue resistance. Imact tests, which are carried out during welding technology qualification, gives answer about ductility, CTOD tests results about material or welded joint ability to dumpping of fatigue crack propagation. CTOD tests have been carried out on order of Morska Stocznia Remontowa "Gryfia".. The expertise contains: methodology of CTOD tests in accordance with NORSOK M101, BS 7448 Part 1&2, PN-EN ISO 15653:2010; details about fatigue pre-crack procedure, measurement system (with gauge made by GUT) details; results for Heat Affected Zone of butt weld (parent material: steel, grade S355G10+M, thicness of 80 mm, welding methods: 136); and conclusions
Deszczówka w zbiorniku
- Ziemowit Suligowski
2014 Magazyn Instalatora
Zasadność polityki rozbudowania zdolności retencyjnej terenów zurbanizowanych. Rozbudowa zbiorników. Ogólne zasady. Przykłady gotowych konstrukcji.
Detection and localization of selected acoustic events in acoustic field for smart surveillance applications
- Józef Kotus
- Kuba Łopatka
- Andrzej Czyżewski
2014 Pełny tekst MULTIMEDIA TOOLS AND APPLICATIONS
A method for automatic determination of position of chosen sound events such as speech signals and impulse sounds in 3-dimensional space is presented. The evens are localized in the presence of sound reflections employing acoustic vector sensors. Human voice and impulsive sounds are detected using adaptive detectors based on modified peak-valley difference (PVD) parameter and sound pressure level. Localization based on signals from the multichannel acoustic vector probe is performed upon the detection. The described algorithms can be employed in surveillance systems to monitor behavior of public events participants. The results can be used to detect sound source position in real time or to calculate the spatial distribution of sound energy in the environment. Moreover, the spatial filtration can be performed to separate sounds arriving from a chosen direction.
Detection of Denatonium Benzoate (Bitrex) Remnants in Noncommercial Alcoholic Beverages by Raman Spectroscopy
- Andrzej Kwiatkowski
- Malgorzata Czerwicka
- Janusz Smulko
- Piotr Stepnowski
2014 Pełny tekst JOURNAL OF FORENSIC SCIENCES
Illegal alcoholic beverages are often introduced into market using cheap technical alcohol, which is contaminated by denatonium benzoate (Bitrex) of very small concentration. Bitrex is the most bitter chemical compound and has to be removed before alcohol consumption. The home-made methods utilize sodium hypochlorite to disintegrate particles of denatonium benzoate in alcohol and to remove bitter taste before trading. In this experimental studies, we propose a novel method that detects in a fast way the remnants of denatonium benzoate in dubious alcohol samples by Raman spectroscopy. This method applies a portable Raman spectrometer of excitation wavelength 785 nm and utilizes the effect of surface-enhanced Raman spectroscopy (SERS) to recognize the suspected alcoholic beverages. High effectiveness (over 98%) of YES/NO classification of the investigated samples was observed when the nonlinear algorithm support vector machine (SVM) was exploited at carefully adjusted detection parameters. The method can identify illicit alcohol within minutes.
Detection of dialogue in movie soundtrack for speech intelligibility enhancement
- Kuba Łopatka
2014
A method for detecting dialogue in 5.1 movie soundtrack based on interchannel spectral disparity is presented. The front channel signals (left, right, center) are analyzed in the frequency domain. The selected partials in the center channel signal, which yield high disparity with left and right channels, are detected as dialogue. Subsequently, the dialogue frequency components are boosted to achieve increased dialogue intelligibility. The techniques for reduction of artifacts in the processed signal are also introduced. Smoothing in the time domain and in the frequency domain is applied to reduce unpleasant artifacts. The results of objective tests are provided, which prove that increased dialogue intelligibility is achieved with the aid of the proposed algorithm. The algorithm is particularly applicable in mobile devices while listening in mobile conditions.
Detection of high frequency current components by residual current devices
- Stanisław Czapp
- Krzysztof Dobrzyński
- Jacek Klucznik
- Robert Kowalak
- Zbigniew Lubośny
- Robert Małkowski
2014
The negative impact of current harmonics on the main components of residual current devices is presented. A solution for the improvement of the operation of residual current devices is proposed.
Detection of sulfonamide resistance genes via in situ PCR-FISH
- Anna Gnida
- K. Kunda
- A. Ziembińska
- Aneta Łuczkiewicz
- Ewa Felis
- Joanna Surmacz-Górska
2014 Pełny tekst Polish Journal of Microbiology
Due to the rising use of antibiotics and as a consequence of their concentration in the environment an increasing number of antibiotic resistant bacteria is observed. The phenomenon has a hazardous impact on human and animal life. Sulfamethoxazole is one of the sulfonamides commonly detected in surface waters and soil. The aim of the study was to detect sulfamethoxazole resistance genes in activated sludge biocenosis by use of in situ PCR and/or hybridization. So far no FISH probes for the detection of SMX resistance genes have been described in the literature. We have tested common PCR primers used for SMX resistance genes detection as FISH probes as well as a combination of in situ PCR and FISH. Despite the presence of SMX resistance genes in activated sludge confirmed via traditional PCR, the detection of the genes via microscopic visualization failed.
Detection of vehicles stopping in restricted zones in video from surveillance cameras
- Grzegorz Szwoch
- Piotr Dalka
2014
An algorithm for detection of vehicles that stop in restricted areas, e.g. excluded by traffic rules, is proposed. Classic approaches based on object tracking are inefficient in high traffic scenes because of tracking errors caused by frequent object merging and splitting. The proposed algorithm uses the background subtraction results for detection of moving objects, then pixels belonging to moving objects are tested for stability. Large connected components of pixels that are stable within a sufficiently long period are extracted and compared with the detected moving objects. Therefore, detection of stationary objects which were previously moving is possible and if the object has stopped in a designated area, the event is declared. The algorithm was evaluated using a real traffic monitoring camera and performance of the algorithm is discussed. The algorithm may be used for automatic detection of potentially dangerous traffic events in video acquired from surveillance cameras.
Detection Range of Intercept Sonar for CWFM Signals
- Jacek Marszal
- Roman Salamon
2014 Pełny tekst Archives of Acoustics
Stealth in military sonars applications may be ensured through the use of low power signals making them difficult to intercept by the enemy. In recent years, silent sonar design has been investigated by the Department of Marine Electronic Systems of the Gdansk University of Technology. This article provides an analysis of how an intercept sonar operated by the enemy can detect silent sonar signals. To that end a theoretical intercept sonar model was developed with formulas that can numerically determine the intercept ranges of silent sonar sounding signals. This was tested for a variety of applications and water salinities. Because they are also presented in charts, the results can be used to compare the intercept ranges of silent sonar and traditional pulse sonar.
Detekcja stanu zakotwienia pręta za pomocą fal sprężystych
- Magdalena Rucka
- Beata Zima
2014 Zeszyty Naukowe Politechniki Rzeszowskiej. Budownictwo i Inżynieria Środowiska
W pracy przedstawiono wstępne wyniki badań eksperymentalnych i obliczeń nu-merycznych mających na celu określenie możliwości oceny stanu zakotwienia pręta stalowego w materiale kompozytowym typu zaprawa. Badanym obiektem był pręt stalowy osadzony w zaprawie o kształcie prostopadłościennym. Analizie poddano pręt stalowy otoczony zaprawą na trzech różnych długościach oraz pręt stalowy swobodny. W jednym z modeli dokonano uszkodzenia w postaci braku współpracy między zaprawą a stalowym prętem na pewnym odcinku. Do detekcji stanu zakotwienia wykorzystano zjawisko propagacji fal sprężystych. W przepro-wadzonych badaniach eksperymentalnych fala została wzbudzona przy użyciu wzbudnika piezoelektrycznego przymocowanego do jednego z końców pręta sta-lowego, natomiast odpowiedź układu została zarejestrowana bezstykowo za po-mocą wibrometru laserowego. Jako wzbudzenie zastosowano ultradźwiękową paczkę falową modulowaną oknem Hanninga. Obliczenia numeryczne propagacji fal przeprowadzono metodą elementów skończonych w środowisku Abaqus/Explicit z zastosowaniem elementów bryłowych. W wyniku obliczeń wy-kazano, że charakter zarejestrowanego sygnału propagującej fali zmieniał się wraz ze zmianą modułu sprężystości zaprawy. Zjawisko wycieku fali do otaczającej bryły zaprawy zwiększało intensywność wraz ze wzrostem wartości modułu sprężystości zaprawy. Identyfikację długości zakotwienia pręta przeprowadzono na podstawie analizy czasów odbić w zarejestrowanych sygnałach fali ultradźwiękowej oraz prędkości jej propagacji.
Determinanty rozwoju przedsiębiorstwa skoncentrowanego na e-biznes
- Ewa Grzegorzewska-Mischka
- Kamil Brodnicki
2014
W artykule przedstawiono istotne czynniki wpływające na rozwój przedsiębiorstwa skoncentrowanego na funkcjonowanie w e-biznesie. Dokonano przeglądu współczesnych systemów informatycznych wspomagających procesy zarządzania. Szczególną uwagę zwrócono na systemy zarządzania relacjami z klientami i systemy planowania zasobów w przedsiębiorstwie. Opisano wpływ systemów handlu elektronicznego na konkurencyjność przedsiębiorstw.
Determination of binder-aggregate adhesion by contact angle measurement
- Robert Aranowski
- Przemysław Wojewódka
- Krzysztof Błażejowski
2014
The key factor in asphalt pavement durability, especially in the presence of water, is adhesion of the bituminous binder to mineral aggregates. There are currently no standard laboratory test procedures that can quickly and accurately measure the strength of the interaction (bond) between the binder and aggregate. In this regard, to evaluate the adhesion force measurements based on the contact angle between the binder and the aggregate by goniometric method were conducted. Contact angles at the mineral-binder-air interface were measured using a high temperature contact angle goniometer by a sessile drop technique. The influence of five adhesion promoters at different temperature (40 to 200°C, 104 to 392°F) for two minerals, granite and limestone, has been investigated. The road binder 35/50 (pen@25°C or @77°F) was used as the bituminous phase. Obtained results show that for granite, for nearly all used promoters, adhesion is better than for pure binder. In case of limestone, the difference of measured contact angles between pure binder and binder with additives is not evident and one can say that activity of some promoters is neutral or adhesion could be even worse. The results of contact angle tests at the full range of temperature can be used also for adhesion assessment for warm mix asphalt (WMA) technologies.
Determination of causes of accelerated local corrosion of austenitic steels in water supply systems
- Jacek Ryl
- Joanna Wysocka
- Kazimierz Darowicki
2014 Pełny tekst CONSTRUCTION AND BUILDING MATERIALS
This paper concerns an inspection of a water supply system, made of AISI 304 steel, which showed signs of local corrosion at the weld. Such corrosion caused material perforation after very short periods of operation. It was revealed that steel was sensitised during the welding process. It was also proven that chromium micro-segregation occurred in the alloy leading to galvanic cell formation which initialised the process of pitting corrosion. This paper is a study of corrosion attack types due to negligence during and after the process of welding of the system.
Determination of Chemical Diffusion Coefficient of Lithium Ions in Ceramics Derived from Pyrolysed Poly(1,2-dimethylsilazane) and Starch
- Andrzej Nowak
- Beata Wicikowska
- Konrad Trzciński
- Anna Lisowska-Oleksiak
2014 Pełny tekst Procedia Engineering
The apparent chemical diffusion coefficient Li+ (DappLI+) in pyrolysed poly(1,2-dimethylsilazane)/starch (PSN/S) (weight ratio: 30/70) ceramic anode composite is determined by galvanostatic intermittent titration technique (GITT). The electrode material composition is C6.00N0.14H0.47O0.12Si0.13. The calculated values of DappLI+, depend on the applied potential, vary from 10-14 to 10-9 [cm2/s]. The diffusion coefficient of lithium ions calculated in this work are similar with the values reported by other authors for carbonaceous anodes.
Determination of Mechanical Properties of P91 Steel by Means of Magnetic Barkhausen Emission
- Katarzyna Makowska
- Zbigniew Kowalewski
- Bolesław Augustyniak
- Leszek Piotrowski
2014 Pełny tekst Journal of Theoretical and Applied Mechanics
In this work, an attempt at determination of mechanical properties by means of a method based on magnetic Barkhausen emission measurements was proposed. The specimens made of P91 steel were subjected to creep or plastic flow which were interrupted after a range of selected time periods in order to achieve specimens with an increasing level of strain. Subsequently, measurements of magnetic Barkhausen emission were carried out, and then static tensile tests were performed in order to check variations of basic mechanical parameters. It is shown that evident relationships between the yield point/ultimate tensile strength and some parameters of the Barkhausen emission exist.
DETERMINATION OF OBJECTIVES FOR URBAN FREIGHT POLICY
- Daniel Kaszubowski
2014 Pełny tekst LogForum
Background: Decisions regarding strategic planning of urban freight transport very often are based on superficial assumptions inadequately reflecting the actual character of encountered challenges. The trend may be observed to adapt isolated solutions without supporting measures and verification of expected outcomes. Selected urban freight solutions have a significant potential to alleviate transport related problems, but they require unorthodox approach beyond standard traffic planning and road management. City's current planning experience must be taken into account to plan an optimized sequence of actions. Method: Due to complexity of the problem and specific decision making factors the analytic network process ANP was selected to determine relevant objective of the urban freight policy. Gdynia was selected as the subject for modeling with a review of the current freight planning practice as a first step. Then, classification of policy objective and their prerequisites were identified supported with descriptive feasibility assessment. This allowed for a development of the ANP decision-making model. Results: Considered objectives for urban freight policy were identified were optimization, reduction and transfer. After verifying relevant decision factors optimization was selected as the most feasible option for Gdynia. Other alternatives were rated around four times lower with a slight prevalence of reduction over transfer. Such ranking reflects current planning practice and availability of transferable experiences. Despite the indicative results, it must be stressed that urban
Determination of parent and methylated polycyclic aromatic hydrocarbons in water samples by dispersive liquid–liquid microextraction–two dimensional gas chromatography–time-of-flight mass spectrometry
- Marek Tobiszewski
- Paulina Bigus
- Jacek Namieśnik
2014 Analytical Methods
Polycyclic aromatic hydrocarbons (PAHs) are contaminants frequently found in environmental waters. Owing to their toxic effects, it is important to develop analytical methodologies that allow their fast and reliable determination. Dispersive liquid–liquid microextraction (DLLME) allows a quick extraction of analytes with little organic solvent consumption. The best results regarding sample preparation are obtained when 40 mL of perchloroethylene is used as the extractant solvent and 1 mL methanol is used as the dispersive solvent; the extraction occurs one minute. Two-dimensional gas chromatography allows good separation of most PAH isomers. The methodology is characterized by good precision (<20% for the most of analytes) and recoveries (73–133%), while the LOD values (single ng L1 for lighter PAHs) rapidly increase with increasing molar mass of the analytes. The methodology greenness assessment with NEMI and Ecoscale have shown that it may be considered as a green methodology. Real sample analysis proved that the procedure is convenient for PAHs determination in environmental and drinking water.