2,261 research outputs found

    Shocks in coupled socio-ecological systems: what are they and how can we model them?

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    Coupled socio-ecological systems (SES) are complex systems characterized by self-organization, non-linearities, interactions among heterogeneous elements within each subsystem, and feedbacks across scales and among subsystems. When such a system experiences a shock or a crisis, the consequences are difficult to predict. In this paper we first define what a shock or a crisis means for SES. Depending on where the system boundary is drawn, shocks can be seen as exogenous or endogenous. For example, human intervention in environmental systems could be seen as exogenous, but endogenous in a socio-environmental system. This difference in the origin and nature of shocks has certain consequences for coupled SES and for policies to ameliorate negative consequences of shocks. Having defined shocks, the paper then focuses on modelling challenges when studying shocks in coupled SES. If we are to explore, study and predict the responses of coupled SES to shocks, the models used need to be able to accommodate (exogenous) or produce (endogenous) a shock event. Various modelling choices need to be made. Specifically, the ‘sudden’ aspect of a shock suggests the time period over which an event claimed to be a shock occurred might be ‘quick’. What does that mean for a discrete event model? Turning to magnitude, what degree of change (in a variable or set of variables) is required for the event to be considered a shock? The ‘surprising’ nature of a shock means that none of the agents in the model should expect the shock to happen, but may need rules enabling them to generate behaviour in exceptional circumstances. This requires a certain design of the agents’ decision-making algorithms, their perception of a shock, memory of past events and formation of expectations, and the information available to them during the time the shock occurred

    Research and automation of restaurant business

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    Microeconomic Motives of Land Use Change in Coastal Zone Area: Agent Based Modelling Approach

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    Economic growth causes growing urbanization, extension of tourist sector, infrastructure and change of natural landscape. These processes of land use change attract even more attention if they take place in coastal zone area. In that case not only the efficient allocation and preservation of natural area, but also reduction of potential damage from flooding is important. Driven forces of land use at macro and micro levels should be taken into account. This paper presents an agent based model (ABM), which is designed to simulate land use change in coastal zone area based of human behaviour. The aim is to understand motives, types of connections and interactions between different actors and natural environment in order to get a feeling how different policy options and natural conditions might affect land use configuration. Microeconomic motives of land use decisions are in the focus of the research. Individual land use decisions are guided by economic and geomorphologic conditions, spatial planning and coastal protection policy. Each location choice is done according to a set of defined rules and land attributes. Space is represented as a grid of cells. Self-interested economic agents interact with each other trying to benefit from a certain type of land-use. We introduce the perception of risk of flooding in the model of land use as an innovative aspect of ABM simulations for water management problems. Based on decisions of spatially distributed individual economic agents operating in a policy framework, the model produces aggregated land-use patterns as an outcome. Understanding the factors that affect land use decisions will help policy makers design incentives to achieve policy objectives in coastal zone area. The proposed ABM will be applied to a study area in the province of North Holland in the Netherlands

    Agent-Based Urban Land Markets: Agent's Pricing Behavior, Land Prices and Urban Land Use Change

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    We present a new bilateral agent-based land market model, which moves beyond previous work by explicitly modeling behavioral drivers of land-market transactions on both the buyer and seller sides; formation of bid prices (of buyers) and ask prices (of sellers); and the relative division of the gains from trade from the market transactions. We analyze model output using a series of macro-scale economic and landscape pattern measures, including land rent gradients estimated using simple regression models. We first demonstrate that our model replicates relevant theoretical results of the traditional Alonso/Von Thünen model (structural validation). We then explore how urban morphology and land rents change as the relative market power of buyers and sellers changes (i.e., we move from a 'sellers' market' to a 'buyers' market'). We demonstrate that these strategic price dynamics have differential effects on land rents, but both lead to increased urban expansion

    Design of non-linear filter in the problem of structural identification of biomedical signals with locally concentrated properties

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    In this paper we propose a generalized method of structural identification of biomedical signals with locally concentrated properties using a digital non-linear filter. The experimental verification of the detecting function was performed by using different ways to describe the model of the desired class of structural elements

    Features of the clinical course of acute otitis media in patients with impaired carbohydrate metabolism

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    The aim of the research: study of the features of the clinical course of acute otitis media (AOM) in patients with impaired carbohydrate metabolism. Materials and methods. We examined 140 patients with AOM aged 19 to 72 years, of which 75 patients with impaired carbohydrate metabolism constituted the main group and 65 patients were included in the comparison group. Taking into account the peculiarities of the pathogenesis of AOM and disorders of carbohydrate metabolism, patients were randomized into 4 groups: 1 – patients with AOM (36), 2 – patients with AOM on the background of sinusitis (29), 3 – patients with AOM on the background of non-insulin-dependent diabetes mellitus (DM type II) (37), 4 – AOM patients with impaired glucose metabolism (38). The patients underwent a general clinical examination, determination of glycosylated hemoglobin, leukocyte indices of intoxication, audiometry, computed tomography (CT) of the temporal bones (if indicated). Results. The proportion of patients with impaired carbohydrate metabolism in 2020 was 32.6 %, of which DM type II was diagnosed in 49.3 % earlier. It was shown that a feature of the clinical course of AOM against the background of impaired carbohydrate metabolism is the discrepancy between the duration of the disease history, complaints and objective data to the state of the cellular structure of the mastoid process according to CT data and impaired auditory function mainly by the type of sound perception, which indicates the formation of latent mastoiditis. Clinically significant complaints and objective data for the differential diagnosis of latent mastoiditis in these patients were determined. The absence of statistical significance of differences in indicators in patients with DM type II and against the background of transient hyperglycemia was revealed, and the concept of the latter was characterized. A direct correlation between blood glucose levels and glycated hemoglobin levels was established in patients with DM type II and AOM. Conclusions. DM type II creates a favorable background for the formation of the clinical course of AOM complicated by latent mastoiditis. From the general contingent of patients with AOM, patients should be distinguished not only with DM type II, but also with transient hyperglycemia for its timely diagnosis. Significant symptoms: pain and a feeling of “heaviness” in the behind-the-ear region in the absence of reactive phenomena, a feeling of “pulsation” in the ear, dizziness, a cloudy eardrum with a protrusion or perforation in the posterior or posterior-upper section, an asymmetric increase in sound perception thresholds above 25 dB. Such patients should be observed with “early” CT scan of the temporal bones

    Changes in the human blood coagulating system during prolonged hypokinesia

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    Changes in the coagulating system of the blood were studied in six subjects during prolonged hypokinesia. Thrombogenic properties of the blood rose in all cases on the 8th day. These changes are explained by stress reaction due to unusual conditions for a healthy person. Changes in the blood coagulating system in the group subjected to physical exercise and without it ran a practically parallel course. Apparently physical exercise is insufficient to prevent such changes that appear in the coagulating system of the blood during prolonged hypokinesia
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