Wyniki 1-7 spośród 7 dla zapytania: authorDesc:"Paweł TCHÓRZEWSKI"

Topological Methods to Determine Damages of Flood Embankments DOI:10.15199/48.2016.12.39

Czytaj za darmo! »

This paper presents a method of testing flood embankment. There was used a specially built laboratory model to determine the moisture level of flood embankments. The finite element method was used to solve the forward problem. The proposed algorithm was initialized by using one step methods and topological sensitivity analysis. There was solved the inverse problem in order to visualize moisture inside objects. There was made possible to change topology during the optimization. The level set method and the Gauss-Newton method have been applied very successfully in many areas of the scientific modelling. Topological algorithms were based on shape sensitivity include the boundary design of the elastic interface. These algorithms are a relatively new procedure to overcome this problem. Streszczenie. Artykuł przedstawia metodę badania wału przeciwpowodziowego. Został zbudowany specjalny model laboratoryjny wału w celu określenia poziomu wilgotności. Do rozwiązania zagadnienia prostego została wykorzystana metoda elementów skończonych. Proponowany algorytm inicjowany jest metodą jednokrokową i rozwiązywany topologiczną analizą wrażliwościową. Rozwiązano zagadnienie odwrotne w celu wizualizacji wilgoci wewnątrz obiektów, poprzez zmianę topologii podczas procesu optymalizacji. Metody zbiorów poziomicowych i Gaussa-Newtona stosuje się z dużym powodzeniem w wielu dziedzinach modelowania naukowego. Metody topologiczne opierają się na analizie wrażliwościowej dostosowując kształt brzegu elastycznego interfejsu. Algorytmy te są relatywnie nowymi rozwiązaniami dla tego typu problemu. (Metody topologiczne do określania uszkodzeń w wałach przeciwpowodziowych). Keywords: Electrical Impedance Tomography, Finite Element Method, Inverse Problem Słowa kluczowe: elektryczna tomografia impedancyjna, metoda elementów skończonych, zagadnienie odwrotne Introduction This paper presents the new method examining the flood embankment dampness by electrical impedance t[...]

e-Medicus System to Segmentation and Analysis Medical Images DOI:10.15199/48.2017.01.48

Czytaj za darmo! »

In this work, there was presented authoring system to exam the medical images by using statistical methods, topological algorithms and computational intelligence methods. These methods are used to identify the properties for the images. There was prepared a special e-Medicus system to machine learning, analysis and compare data and pictures. The solution shows the architecture of the system collecting and analysing data. There was tried to develop an algorithm for level set method (LSM) applied to piecewise constant image segmentation. These algorithms are needed to identify arbitrary number of phases for the segmentation problem. The image segmentation refers to the process of partitioning a digital image into multiple regions. There is typically used to locate objects and boundaries in images. Streszczenie. W artykule, został przedstawiony autorski system do badania obrazów medycznych przy użyciu metod statystycznych, algorytmów inteligencji obliczeniowej i metod topologicznych. Metody te stosuje się w celu identyfikowania właściwości obrazów. Przygotowano specjalny system e-Medicus do uczenia maszynowego, analizy i porównywania danych i obrazów. Rozwiązanie przedstawia architekturę systemu do gromadzenia i analizy danych. Opracowano algorytmy oparte na metodzie zbiorów poziomicowych (MZP) jako odcinkowo stałej segmentacji obrazu. Algorytmy te są potrzebne do identyfikacji dowolnej liczby faz dla problemu segmentacji, która odnosi się do procesu dzielenia cyfrowego obrazu w różnych regionach. Używana jest zwykle do lokalizacji obiektów i brzegów w obrazach. (System e-Medicus do segmentacji i analizy obrazów medycznych). Keywords: Electrical Impedance Tomography, Image Analysis, Level Set Method Słowa kluczowe: tomografia impedancyjna, analiza obrazów, metoda zbiorów poziomicowych Introduction In medical clinical research and practice, imaging has become an essential part to diagnose and to study anatomy and function of the human body. T[...]

Electrical Capacitance Tomography and Optical Detection in Quality Control System DOI:10.15199/48.2017.12.53

Czytaj za darmo! »

Modern production processes are increasingly complex, while customers are demanding higher quality products at the lowest price. This situation increases the importance of process optimization. Products and requirements are changing faster and faster, technologists have less and less time to learn the process and to optimize it solely on the basis of their own experience. On the other hand, very often the processes are automated and metered in detail, so we have plenty of data describing it. Analysis of the data may be used for process optimization in different ways and it can affect many aspects of process management. We can detect disturbances in the process, find the causes affecting the problems with quality, and choose the optimal settings for the process, comparing different preparation procedures and many others. It is worth noting that in the processes, there are many people involved in with different tasks and permissions. Therefore, data analysis tool should provide access control. The research project assumes creation of two measurement platforms: a set of multiphase flow system and a mini production line. In the first case we will be analysing two-phase flows of liquid (water) and air. That type of flow is commonly used in chemical reactors where air is mixing substances [4,9,10]. Electrical Capacitance Tomography Electrical capacitance tomographs are devices capable of performing analysis of pipeline fragment or a vessel filled with examined medium [15]. Obtained cross-section’s image reconstruction can be analysed further for an automated quality control system’s autonomous and correct decision. However, existing industrial solutions are still of significant size and structurally complex [2,4,5]. This fact greatly limits the number of actual deployments. Decision makers are afraid of electrical capacitance tomography (ECT) implementation due to high costs of possible equipment failures and because[...]

The concept of the technological process control using a distributed industrial tomography system DOI:10.15199/48.2018.12.36

Czytaj za darmo! »

Industrial tomography enables non-invasive, dynamic observation of physical and chemical phenomena without the need of mechanical interference into the interior of the investigated object [1-14,16,19-22]. Thanks to the features mentioned above, this type of tomography is ideal for automatic optimization of design and production processes. Process tomography systems can operate autonomously in the field of monitoring, measurement and control of the correct functioning of industrial processes. A network of sensors connected to the system provides a constant data flow enabling tracking of technological processes even in closed technical facilities, such as fermenters. Process tomography is also used to acquire data on the flow of fluids and loose components in pipelines that act as transport media [24-29, 31-37]. The data obtained from the sensors are delivered to the data warehouse, where they are further processed. As a consequence, data warehouses enable building a knowledge base on operating systems and processes. Data analysis results can be displayed in a suitable form on the monitor screen. In semi-automatic systems they can be used by the operator as elements of supporting decision-making processes, and in automatic systems, decisions are made by IT systems, and the information about the history of these decisions is a log file. The production process control tasks carried out in this way allow increasing the efficiency and quality of products, as well as increasing the company's competitiveness level. Methods of analysis and control of processes include issues related to the processing of data obtained from various sensors located in remote nodes. Monitoring is based on acquired and processed data due to appropriately elaborated algorithms for parameter automation [15,17,18,23,30,38]. This paper concerns the issues of processes control in a cyber-physical system based on the concept of a production process managemen[...]

Monitoring of flood embankments with the use of tomographic systems with distributed architecture DOI:10.15199/48.2018.12.37

Czytaj za darmo! »

The disaster of the flood embankment often results in large economic and social losses, as was the case in Poland during the flood in 2010. One of the main threats to the safety of the embankment is the development of filtration and erosion processes both in its body and the ground. The existing practice of monitoring and assessing the condition of flood embankments is insufficient to ensure the safety of these facilities. They are based primarily on local inspection and the implementation of geotechnical research in cross-sections spaced from each other. The basic disadvantage of traditional methods is their point (local) character. Identification of filtration and erosion processes, especially in their initial phase of development and assessment of their kinetics with these methods is usually impossible. Designing shafts due to their location, shape and material is quite complicated [19,20]. Monitoring of flood protections requires methods and systems which will have the following features: monitoring of destructive processes in real time during floods, continuous monitoring of space in the space, monitoring of early and precise detection of the destructive process, the possibility of evaluating the kinetics of the destructive process, the possibility of developing an automatic alarm system informing about the occurrence of a destructive process, a damage-resistant installation operating without a maintenance service. Data acquisition In systems based on the electrical tomography (ET) method, the data acquisition system collects measurements of the voltages generated by the electrodes [1-5,7-9, 17, 17- 25]. These types of data can be processed locally or can reach the central analytical system. It mainly depends on such factors as: the geospatial dimensions of the monitored object, the computational power of the ET device, as well as the required resolution of the reconstructed image. Traditional data collection and pro[...]

Area monitoring using the ERT method with multisensor electrodes DOI:10.15199/48.2019.01.39

Czytaj za darmo! »

Tomography is a technique that allows obtaining a cross-sectional image of the examined object on the basis of data from the measurement of a given physical value (radiation, capacity, resistance, etc.) at selected points usually lying on the edge of the tested area. The resulting measurement vector is used to reconstruct the crosssection image using appropriate algorithms. The obtained image represents the distribution of a certain feature of the examined object depending on the type of tomography used. It can be material density, concentration, electrical permittivity, conductivity, etc. Electrical tomography covers many tomographic imaging methods based on the processing of various electrical parameters [1,3,4,7,9,10,12-14]. Despite the fact that many methods have already been developed for assessing damage to flood embankments, there is no single universal tool for their diagnosis and monitoring. In this paper, a new method for testing flood embankments and landfills by means of electrical resistive tomography (ERT) was presented. For the needs of the research, a special measuring system was developed with special multisensor electrodes for depth measurements using ERT. The algorithms used for image reconstruction were based on gradient and topological methods. After minor modifications, it is possible to apply the discussed technique to solving reverse problems in electrical tomography [6, 18-23]. The combination of tomographic techniques with reconstruction algorithms allowed non-invasive and more accurate spatial assessment of seepages and damages to flood protections. Model Electric tomography including ERT enables non-invasive measurements of various types of technical objects. The i[...]

A hybrid tomography for assessing the moisture level of walls and building condition DOI:10.15199/48.2019.02.23

Czytaj za darmo! »

The non-destructive method [4,20,26,27,34] of brick wall insulation is tested using electrical impedance tomography (EIT). The aim of the presented method is to obtain image reconstruction using the proposed solution. The set was used to determine the humidity of the test wall on specially constructed models. The presented algorithms have been successfully used in the reconstruction of model wall measurement data. These approaches were based on the sensitivity analysis. An effective algorithm for solving forward and inverse problems would also improve many numerical results of the proposed methods. In modeling the problem in electrical tomography, it is required to identify unknown conductivities from near-limit potential measurements [17-19,21]. The discussed technique can be used to solve inverse problems in electrical impedance tomography. Fig. 1. Hybrid tomography system. Electrical tomography consists in restoring the conductivity of the interior of the tested object with the knowledge of currents and tensions imposed on its surface. Most of the available research methods allow only a point evaluation of moisture, thanks to which it is possible to achieve only the discrete distribution itself. Permeation of moisture in the walls of old buildings, which are in direct contact with the soil, leads to migration of soluble salts in relation to many wall problems. Building porous materials (eg bricks or concrete), both natural and made, has pores (like a sponge). The data collection system collects the measured voltage from the electrode and then processes the data [1-3,5-11,13-15,28-33]. Figure 1 presents the model of a hybrid tomography system. Measurement system The electrical tomography is a technique of i[...]

 Strona 1