A Cognitive Model of an Epistemic Community: Mapping the Dynamics of Shallow Lake Ecosystems

We used fuzzy cognitive mapping (FCM) to develop a generic shallow lake ecosystem model by augmenting the individual cognitive maps drawn by 8 scientists working in the area of shallow lake ecology. We calculated graph theoretical indices of the individual cognitive maps and the collective cognitive map produced by augmentation. The graph theoretical indices revealed internal cycles showing non-linear dynamics in the shallow lake ecosystem. The ecological processes were organized democratically without a top-down hierarchical structure. The steady state condition of the generic model was a characteristic turbid shallow lake ecosystem since there were no dynamic environmental changes that could cause shifts between a turbid and a clearwater state, and the generic model indicated that only a dynamic disturbance regime could maintain the clearwater state. The model developed herein captured the empirical behavior of shallow lakes, and contained the basic model of the Alternative Stable States Theory. In addition, our model expanded the basic model by quantifying the relative effects of connections and by extending it. In our expanded model we ran 4 simulations: harvesting submerged plants, nutrient reduction, fish removal without nutrient reduction, and biomanipulation. Only biomanipulation, which included fish removal and nutrient reduction, had the potential to shift the turbid state into clearwater state. The structure and relationships in the generic model as well as the outcomes of the management simulations were supported by actual field studies in shallow lake ecosystems. Thus, fuzzy cognitive mapping methodology enabled us to understand the complex structure of shallow lake ecosystems as a whole and obtain a valid generic model based on tacit knowledge of experts in the field.Comment: 24 pages, 5 Figure

Determinants of financial information disclosure: A visualization test by cognitive mapping technique

AbstractThe purpose of this paper is to examine determinants of financial information disclosure by Tunisian companies. The methodology is based on qualitative approach, using the cognitive mapping technique. To take into account the specificities of the Tunisian economic, we felt that it is essential to conduct a qualitative analysis in the light of which we can identify the factors motivating the disclosure of financial information. The qualitative analysis is based on the census via a set of cases carried out in several Tunisian companies to understand their perceptions regarding the determinants of financial disclosure

Plithogenic Cognitive Maps in Decision Making

Plithogenic sets introduced by Smarandache (2018) have disclosed new research vistas and this paper introduces the novel concept of plithogenic cognitive maps (PCM) and its applications in decision making. The new approach of defining instantaneous state neutrosophic vector with the confinement of indeterminacy to (0,1] is proposed to quantify the degree of indeterminacy. The resultant vector is obtained by applying instantaneous state vector through the connection matrix together with plithogenic operators comprising the contradiction degrees. The connection matrix is represented as fuzzy matrix and neutrosophic matrix and the resultant vector is determined by applying plithogenic fuzzy operators and plithogenic neutrosophic operators respectively. The obtained results are highly feasible in making the decision as it incorporates the contradiction degree of the conceptual nodes with respect to the dominant node. This research work will certainly pave the way for developing new approaches in decision making using PCM

Reasoning with linguistic preferences using NPN logic

Negative-positive-neutral logic provides an alternative framework for fuzzy cognitive maps development and decision analysis. This paper reviews basic notion of NPN logic and NPN relations and proposes adaptive approach to causality weights assessment. It employs linguistic models of causality weights activated by measurement-based fuzzy cognitive maps' concepts values. These models allow for quasi-dynamical adaptation to the change of concepts values, providing deeper understanding of possible side effects. Since in the real-world environments almost every decision has its consequences, presenting very valuable portion of information upon which we also make our decisions, the knowledge about the side effects enables more reliable decision analysis and directs actions of decision maker

From Ecosystem Services to Ecosystem Benefits: Unpacking the Links Between Ecosystems and Human Well-Being in Agricultural Communities in Costa Rica

This dissertation presents an exploration of the links between ecosystem services and human well-being in resource-dependent communities in diverse agricultural regions in Costa Rica. As such, this dissertation considers the key roles played by environmental management and environmental governance. In broad terms, the question that this dissertation examines is: How does the management of ecosystem services derived from agriculture impact human well-being in resource-dependent communities in Costa Rica? This dissertation has taken as a point of departure the framework proposed by the Millennium Ecosystem Assessment and has applied it to the examination of communities that are particularly vulnerable to environmental change. The focus on well-being brings to the forefront questions about the distribution of the benefits derived from ecosystems and highlights the perceptions of ecosystem-users. Three manuscripts make up this dissertation: The first manuscript uses a participatory method (photovoice) to elicit narratives about the ecosystems that impact the well-being of residents in the pineapple community of Volcán in South-Pacific Costa Rica. The manuscript offers a community-level perspective on the ecosystem services that contribute to the well-being of agricultural communities. The second manuscript focuses on how access and power relations affect the benefits experienced by Indigenous farmers in the Bribri Territory who produce plantains for sale in the national and international markets. The manuscript identifies how access to the means of production is gained, controlled and maintained within the social-ecological system of plantain agriculture. It also identifies the mechanisms that gatekeepers employ to exercise their power. The manuscript concludes with possible leverage points that could be used to challenge existing power relations and improve human well-being in the Bribri Indigenous Territory. The third manuscript presents three community-level assessments of well-being from agricultural regions on the Caribbean side of Costa Rica that have different environmental management systems ranging from large-scale monocrop banana plantations in Matina to agroforestry in the Bribri Indigenous Territory. The analysis investigates the ways in which different systems of resource extraction shape well-being at the local level. In brief, the dissertation offers insights for improving the theoretical and empirical understandings of how changes in ecosystems affect human well-being in resource-dependent communities. It also offers suggestions to render the ecosystem services framework more relevant to guide environmental management at the micro-scale and in the context of poverty alleviation

A study of mobile robot motion planning

This thesis studies motion planning for mobile robots in various environments. The basic tools for the research are the configuration space and the visibility graph. A new approach is developed which generates a smoothed minimum time path. The difference between this and the Minimum Time Path at Visibility Node (MTPVN) is that there is more clearance between the robot and the obstacles, and so it is safer. The accessibility graph plays an important role in motion planning for a massless mobile robot in dynamic environments. It can generate a minimum time motion in 0(n2»log(n)) computation time, where n is the number of vertices of all the polygonal obstacles. If the robot is not considered to be massless (that is, it requires time to accelerate), the space time approach becomes a 3D problem which requires exponential time and memory. A new approach is presented here based on the improved accessibility polygon and improved accessibility graph, which generates a minimum time motion for a mobile robot with mass in O((n+k)2»log(n+k)) time, where n is the number of vertices of the obstacles and k is the number of obstacles. Since k is much less than n, so the computation time for this approach is almost the same as the accessibility graph approach. The accessibility graph approach is extended to solve motion planning for robots in three dimensional environments. The three dimensional accessibility graph is constructed based on the concept of the accessibility polyhedron. Based on the properties of minimum time motion, an approach is proposed to search the three dimensional accessibility graph to generate the minimum time motion. Motion planning in binary image representation environment is also studied. Fuzzy logic based digital image processing has been studied. The concept of Fuzzy Principal Index Of Area Coverage (PIOAC) is proposed to recognise and match objects in consecutive images. Experiments show that PIOAC is useful in recognising objects. The visibility graph of a binary image representation environment is very inefficient, so the approach usually used to plan the motion for such an environment is the quadtree approach. In this research, polygonizing an obstacle is proposed. The approaches developed for various environments can be used to solve the motion planning problem without any modification. A simulation system is designed to simulate the approaches