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Auflistung nach Autor:in "Nahorski, Zbigniew"

1 - 5 von 5
  • Konferenzbeitrag
    Applications of Systems Analysis in Solving Problems Related to Environment
    (Environmental Informatics and Systems Research, 2007) Hryniewicz, Olgierd; Nahorski, Zbigniew
    The paper presents presuppositions and examples of application of the systems analysis methodology in the environmental problems. The examples come from the activity of the Systems Research Institute of the Polish Academy of Sciences, but are quite typical for other institutions working in the system research area. Having presented some basic system analysis tools, two cases involving model-based analysis are shortly outlined: air transportation of pollutants and their impact on nature and human health, and wastewater treatment modeling. Then some research projects connected with the global climate change are described in more details. They deal with solving the problems of high uncertainty in greenhouse gases inventories, which have to be coped with in checking compliance and in permits trading, as well as with processing the greenhouse gases emission time series to extract knowledge and parameters useful for further modeling.
  • Konferenzbeitrag
    Generation of inputs to renewable energy sources using matched-block bootstrap approach with fitness proportionate selection
    (Proceedings of the 27th Conference on Environmental Informatics - Informatics for Environmental Protection, Sustainable Development and Risk Management, 2013) Radziszewska, Weronika; Nahorski, Zbigniew
    Renewable energy sources produce clean, green energy, but their production is highly variable in time due to changeable weather conditions. Energy management systems are implemented to cope with that problem. Their proper design requires an exhaustive testing. Creation of realistic test cases requires certain amount of test data (such as wind speed and insolation). As the required amount of measured data is usually not available, they have to be generated in a way that preserves the statistical qualities of the real life phenomenon. In this article a matched-block bootstrap with fitness proportionate selection method is presented. It is a non-parametric method that samples data blocks from a real data set and concatenates them into a new data set. To model the seasonal cycles (especially visible for temperature and solar irradiance) the blocks in the bootstrap method are categorized by month, day and time, creating sets of subsequent blocks from different years with the same time and date. To maintain the coherence of data, the fitness proportionate selection methods are introduced. They provide mechanisms to choose better matching blocks with higher probability. Two fitness functions are considered for this, one using an inversion and another using a negation operation. The matched-block bootstrap methods were tested using 9 years of measurements of solar irradiance and 10 years of data of wind speed in central Poland both taken at 10-minute intervals. The generated time series have the same values for the basic statistic factors as the original data and allow for creating test sequences of an arbitrary length.
  • Konferenzbeitrag
    Impact of the Pollution Emission Limits on Technological Structure of Production. A Modelling Approach1
    (Environmental Informatics and Systems Research, 2007) Gadomski, Jan; Nahorski, Zbigniew
    One-sector macroeconomic model with three competing/coexisting production technologies is considered. It is assumed that the producers choose between distinct technologies, which correspond to different generations of capital: (i) the cheapest dirtiest (“old”) one, the least capital intensive, (ii) a more expensive one being more capital intensive but less polluting, (iii) the cleanest but the most expensive one. The model is an optimizing one. It describes the behavior of an economy, provided the economic agents have perfect knowledge about the future and their goal functions are explicit and identical. The constraints included are those related to the technology of production as well as those representing social and political aspects of the economic policy (the minimum consumption rate, maximum debt to GDP rate). Under the assumption that there is no technical progress the results dismally indicate that the zero economic growth is inevitable. This outcome can, however, be averted by adding the technical progress. The model may be used for analysis of different scenarios of economic growth, emissions of pollutants, and ecological policy, as well as technical changes (progress) in production.
  • Konferenzbeitrag
    Modeling of power consumption in a small microgrids
    (Proceedings of the 28th Conference on Environmental Informatics - Informatics for Environmental Protection, Sustainable Development and Risk Management, 2014) Radziszewska, Weronika; Nahorski, Zbigniew
    Development of energy management systems and models of power grids are popular topics of many research projects. Unfortunately, quite often the behavioral tests with load data are not present. It is due to the difficulty of representing and collecting data about the power usage. To obtain such data it is required to deeply analyze operation lifecycle of certain devices and information about statistics of human behavior, as well as the patterns of people actions. Although many devices time profiles have been published, they lack characterization of variability of behavior and uncertainty. The paper presents some alternative ways to model power usage: probability profiles, rules and a mix of them. The purpose is to create a simulator for testing performance of energy management systems in a small microgrid.
  • Konferenzbeitrag
    Modelling, Compliance, and Permit Trading Under Big Uncertainties in Reporting: Greenhouse Gases Case1
    (Informatics for Environmental Protection - Networking Environmental Information, 2005) Nahorski, Zbigniew; Horabik, Joanna; Jęda, Waldemar; Jonas, Matthias
    In this paper we address the problem of proving compliance and emission trading with high uncertainties of greenhouse gas inventories reported within the Kyoto Protocol. We introduce a risk of noncompliance and transfer this notion into emission trading framework constructing a market with effective emission permits reflecting participants’ inventory quality. A simulation of the market is performed. We discuss uncertainty distribution modelled within interval, stochastic and fuzzy settings.