Andrzej Leśniak

A Model of a System for Stream Data Storage and Analysis Dedicated to Sensor Networks of Embankment Monitoring

Contemporary monitoring systems are a source of data streams. Processing of this data is an interesting issue from both a performance and data storage perspective. It is worth paying attention to the concept of stream database management systems, which are a hybrid that allows for efficient analysis of the data stream and provide a set of implemented statistical methods.

A Concept of Time Windows Length Selection in Stream Databases in the Context of Sensor Networks Monitoring

Monitoring systems are a source of large amounts of data. These streams of data flow down as information which, in the case of sensor networks is often associated with the measurement of the selected physical signals. Processing of these data is a non-trivial issue, because accurate calculations often require dedicated solutions and large computing power.

Parallelization of the seismic ray trace algorithm

This article presents the parallelization of seismic ray trace algorithm. The chosen Urdanetas algorithm is shortly described. It provides wavelength dependent smoothing and frequency dependant scattering thanks to the implementation of Lomaxs method for approximating broad-band wave propagation. It also includes Vinje et al. wavefront propagation technique that provides fairly constant density of rays. Then the parallelized algorithm is preliminarily tested on synthetic data and the results are presented and discussed.

An Attempt to Automate the Simplification of Building Objects in Multiresolution Databases

The paper presents a method for the simplification of building objects in multiresolution databases. The authors present a theoretical foundation, practical ways to implement the method, examples of results, as well as a comparison with currently available generalization methods in commercial software. This algorithm allows the verifiability and reproducibility of results to be kept while minimising graphic conflicts, which are a major problem during the automatic generalisation process. These results are achieved by defining the shape of buildings, employing classification rules and adopting minimum measures of recognition on a digital map. Solutions included in this paper are universal and can successfully be used as a component in any automated cartographic generalisation process. Moreover, these methods will help to get closer to full automation of the data generalisation process and hence the automatic production of digital maps.

A decision support system for emergency flood embankment stability

Abstract This article presents a concept of decision support system for emergency flood embankment stability. The proposed methodology is based on the analysis of data from both a flood em-bankment measurement network and generated through numerical modeling. Decisions about the risk of embankment failure are made based on this analysis. The authors present both the general concept of the system as well as a preliminary detailed description of the system components.

Reducing Flood Risk using Computer System for Monitoring River Embankments

Abstract In order to learn about the phenomena occurring in flood embankment under the influence of external factors, including the increasing water level in the river during floods, a Computer System for Monitoring River Embankment (ISMOP) was developed using an experimental flood embankment. The project was carried out by a consortium consisting of AGH University of Science and Technology departments (Computer Science, Hydrogeology and Engineering Geology, Geoinformatics and Applied Computer Science and two companies (NEOSENTIO and SWECO Hydroprojekt Kraków) in co-operation with the Czernichów Community Council. An experimental flood embankment was built with two parallel sections with a length of 150 m and a height of 4.5 m, connected by a meandering, creating a reservoir that can be filled with water. For the construction of the embankment, different types of soils were used in all the five sections. Inside the flood embankment 1300 sensors are placed, including sensors for temperature, pore pressure, vertical displacements, as well as inclinometers. Also fiber optic strands, capable of measuring the temperature of the flood embankment on the upstream side, are located inside the experimental embankment [ismop.pl]. Together with the real experiments, numerical modelling using the Itasca Flac 2D 7.0 was performed in order to describe the impact of water pressing on the flood embankment and the impact of increasing and decreasing reservoir water level on the phenomena that occur within the embankment. The results of modelling compared with the real sensor data allowed the evaluation of the current and future state of the embankment. Based on the data measured by the sensors and data received during the numerical modelling, a group of algorithms that allowed detection of anomaly phenomena was developed.

Influence of initial water saturation in earthen levees on results of numerical modelling of infiltration processes

Levees in Poland are mostly earthen constructions. The stability of earthen levees depends largely on factors such as the construction material, meteorological conditions and natural elements. The influence of initial water saturation of pore space on levee stability is analysed in this paper. Analysis was performed using numerical modelling and water pore pressure results were compared against data obtained from sensors located in a levee. The numerical modelling shows the moderate influence of initial water level on distribution of water pore pressure during high water level.

ANALYSIS OF THE POLISH HOME ARMY DROP ZONES DURING WORLD WAR II, USING GEOGRAPHIC INFORMATION SYSTEMS

The aim of the research presented in this paper was to determine the precise location of drop zones that were used for parachute jumps of the ‘Silent and Unseen’ paratroops (Polish: Cichociemni) and for delivering military equipment during World War II. The studies were based on historical research containing information about the locations of the jumps and their schematic arrangement, Ordnance Survey Maps of the pre-war period, and a GIS system with contemporary geographic digital maps. Within the work, the available information about the drop zone locations of the period from February 1941 to December 1944 is summarized. Moreover, the calibration of available schematic maps is presented, based on contemporary digital data. The final part of the study contains an estimation of drop zone location errors compared against military tactical maps.

Analysis of annual temperature distribution inside the experimental embankment

The aim of this paper is analysis of temperatures distribution inside experimental embankment from August 2015 to September 2016. Analysis was carried out in order to interpretation of the results of the flood experiments performed on the experimental embankment. The reference for year temperature changes in the embankment at various depths was obtained. A simplified model of temperature changes depending on the depth was made. The model parameters which can be used for modelling the temperatures in the embankment during the experiments were estimated.

Optimal selection of numerical models for flood embankment pore pressure and temperature data

The aim of the ISMOP project is to study processes in earthen flood embankments: water filtration, pore pressure changes, and temperature changes due to varying water levels in the riverbed. Developing a system for continuous monitoring of flood embankment stability is the main goal of this project. A full-size earthen flood embankment with built-in sensors was built in Czernichow and used to conduct experiments involving the simulation of different flood waves, with parameters mostly measured at time intervals of 15 minutes. Numerical modelling—in addition to providing information about phenomena occurring in the embankment due to external factors and changes in water level—could be used to assess the state of the embankment. Modelling was performed using Itasca Flac 2D 7.0 with an assumed grid cell size of 10x10 cm. The water level in the embankment simulated the water flow in the Wisla River and the temperature of the air and water. Data about the state of the flood embankment was exported every hour. Using numerical models and real experiment data, a model-driven module was used to perform comparisons. Analyses of each half-section of the flood embankment were carried out separately using similarity measures and an aggregate window. For the tests, the North-West (NW) half cross-section of the embankment was chosen, which contains pore pressure and temperature sensors UT6 to UT10. The water level in the embankment was raised to a height of 3m; the best numerical model was considered the one that best matched the actual data recorded by the sensors during the experiment. The experiment period was from 9pm on 29/08/2016 to 9am on 03/09/2016. Seventeen numerical models of the water level rising to 2, 3, and 4 meters were compared against real experimental data from the NW half cross-section. The first step was to verify the similarity between the incoming data from the sensors. If the correlation value exceeded 0.8, the data from the sensors was averaged. The experimental data was then compared against the numerical models using least absolute deviations L1-Norm. The L1-Norm varied from 26 to 32, depending on window length and the numerical model used.