Displaying 16 - 30 of 39 records found.
Title | Type Created |
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the coupled dynamics of human socio-economic choice and lake water system: the interaction of two sources of nonlinearity | Model |
here, we present a model of the coupled dynamics between human socioeconomic choice (between cooperative and non-cooperative collective action) and nutrient loading input level into a lake water system. suzuki and iwasa (2008) explains the model as the following. "in the model, many players choose one of the two options: a cooperative and costly option with low phosphorus discharge, and an economical option with high phosphorus discharge. the choice is affected by an economic cost, a... | 09 Aug 2016 |
conflict between groups of players in coupled socio-economic and ecological dynamics | Model |
this is a model for the coupled dynamics of conflict between two different user groups regarding their socioeconomic choice (between cooperative and non-cooperative collective action) and nutrient loading input level into a lake water system. suzuki and iwasa (2009),gives the following overview of the model. "conflict among multiple groups is a major source of difficulty in environmental conservation. people are often divided into various groups that have different social factors,... | 09 Aug 2016 |
paradox of marine protected areas: suppression of fishing may cause species loss | Model |
this is a simple model of a prey-predator system in two areas, one of which receives fishing activity (fishing ground) and another that does not (mpa: marine protected area). takashina et al. 2012 gives the following description of the model. "a number of fish and invertebrate stocks have been depleted by overexploitation in recent years. to address this, marine protected areas (mpas) are often established to protect biodiversity and recover stocks. we analyzed the potential impact of... | 09 Aug 2016 |
non-linear dynamics of population and natural resources: the emergence of different patterns of development | Model |
this model explores the long-term dynamic interaction between the exploitation of natural resources and population growth. this is a variant of brander and taylor (1998). the reference article, d'alessandro (2007), gives the following description of the model. "two new assumptions are introduced: i) the disaggregation of the ecological complex into two different resources; ii) irreversibility --namely, an inexorable tendency to exhaustion when the renewable resource stock is below a... | 09 Aug 2016 |
tourists and traditional divers in a common fishing ground | Model |
a social-ecological model of a fishing ground open to eco-tourism is presented here. to assess the impact of introducing eco-tourism on the welfare of the fishing association and on the resource level, lee and iwasa (2011) constructs a model in which the fishing association charges an entrance fee to tourists. the level of the fee is chosen to regulate tourist number as well as maximing benefits accrued to the fishing association (combined revenue from tourism and conventional fishing by... | 09 Aug 2016 |
subtle global bifurcation with dramatic ecological consequences in a simple population model | Model |
this model presents an example of a global bifurcation (a heteroclinic connection). the model is a three-dimensional system with two resources and a single consumer, where one of the resources is fixed and the other is reproductive. by assuming that, for all values of resource consumers (c) below its carrying capacity (k), the fixed resource facilitates the consumption of the reproductive resource, the system can be reduced to a two-dimensional system. the reference article, vandermeer and king... | 09 Aug 2016 |
the inevitability of surprise in agroecosystems | Model |
this is a simple model of competition between noxious and benigne weeds in an agroecosystem based on predator-prey dynamics. the interesting aspect of this model is that it demonstrates the inevitability of surprises in system behavior - meaning that for some systems, early warning signals (e.g, increased variance or autocorrelatin) are almost non-existent prior to critical transitions in systems. the reference article, vandermeer (2011), gives the following overview. "many critical... | 09 Aug 2016 |
the discrete logistic | Model |
the logistic is the simplest representation of population dynamics that contains a minimum level of biological realism. if we imagine a population of individuals at time t, the number of individuals in the next period (periods can range from seconds to days to decades depending on the organism) is the number of individuals now plus the number of births minus the number of deaths. if we assume in the simplest case there are no environmental constraints on births or deaths, then it is... | 09 Aug 2016 |
effect of infrastructure design on commons dilemmas | Model |
the authors address the question of how infrastructure design affects ses sustainability in two stages. first, they explore the effects of design variations in shared infrastructure on long-term system behavior in a model system. they examine two types of distribution infrastructure, one with and one without upstream downstream asymmetry, and different threshold characteristics of infrastructure maintenance. second, they evaluate how these design variations influence the robustness of system... | 09 Oct 2016 |
modeling human ecodynamics and biocultural interactions in the late pleistocene of western eurasia | Model |
exploring the dynamic feedbacks between biological and cultural evolutionary systems is critical to understanding the origins of modern human behavior. the authors present a population dynamics model using ordinary differential equations and agent based modeling to delineate the consequences of differing mobility strategies expressed as reproduction potential at the population level for late pleistocene hominins in western eurasia (i.e., modern homo sapiens and neanderthals). the model... | 29 Nov 2017 |
resource dynamics under harvest and sunk cost effects | Model |
this is a simple model for resource dynamics under harvest. the authors added expected effects of investment in fixed structures on the dynamics of settlement. these sunk-cost effects are not included in this simple model. the authors introduce a model of logictically regrowing resource exploited by a consumer. there is only one variable, which is level of local renewable sources. parameters are: local renewable resources (r), settlement of humans (h), maximum growth rate (g), maximum level of... | 29 Nov 2017 |
fractal poverty traps | Model |
the dynamic model for poverty traps contains parameters as government policies and technologies, and variables such as income, expenditures, assets holdings and anthropometric status. this dynamic model for poverty traps offers a new perspective by showing the existence of multiple stable equilibria, which implies that there's one unstable dynamic equilibria. at this unstable equilibria, any little shock in the system will cause a switch to state equilibrium. different to the standard... | 29 Nov 2017 |
mathematics of marital conflict | Model |
this discrete time model represents a coupled system as seen through talk turns in a conversation between a wife and husband where each exerts influence dynamically on the other. cook et al. (1995) develop this entirely social model based on empirical observations of marital conflict in the gottman love lab, a university of washington social laboratory studying marital conflict and resolution. the authors developed this model, then confirmed the model through turn-wise application of the model... | 30 Nov 2017 |
ecological-economic model for optimal control of fire-driven, semi-arid rangelands | Model |
this is an ecological-economic model that endogenizes discontinuous change between states of fire-driven, semi-arid rangelands which may exist in varying degrees as grassland and woodlands depending partly on the given soil conditions. more sandy soils will result in woodlands, whereas clay soils will more likely result in grasslands. one of the critical features of this model is the existence and impact of fires on these different types of rangelands. grasslands may build up biomass and create... | 01 Oct 2016 |
dynamics of coupled populations in an open, three-trophic-level system | Model |
this model explicitly incorporates the immigration and emigration processes in the context of three-trophic-level systems (e.g., a stream reach), and reveals how the coupled populations will change in response to the primary-productivity gradients (e.g., r, k). in contrast, traditional simple food-chain models study mostly two-trophic-level system which can be open or close. more interstingly, though not reflected here, there are two contrasting models presented in the paper: the discrete-... | 09 Oct 2016 |