Conceptual models Sample Clauses
Conceptual models. Conceptual models are diagrams of key variables and interactions, representing the dynamic nature of a system, including interconnections, feedback loops and delays (▇▇▇▇▇▇▇, 2000). Such graphical tools are generally far more transparent and easy to understand, especially for non-specialists. As such, conceptual models can be used in many (non-)scientific fields because they are participatory and transparent. Establishing a conceptual model is a demanding task because the processes involved are dynamic, interdependent, complex and non-linear. These processes may not be completely understood. Each model must be designed to answer specific questions. Models should not start with data and quantitative modelling, but should start by defining the system boundaries, the goal of the model and the key interactions. Only once this conceptual model is well defined should numerical modelling proceed. The use of a conceptual model leading to formal SDM development offers the advantage of being able to partition a very complex system into number smaller sub-systems describing different elements of the larger system, making the modelling process more manageable. Conceptual models can be developed for each sub- system, then linked together to form an overall model of the larger system under consideration. This approach was pursued in the AQUASTRESS project (▇▇▇▇▇▇▇▇ et al. 2010, AQUASTRESS, 2006). Conceptual models are generally represented as diagrams showing key system components interconnected with directed arrows. It can be drawn without being linked to a specific software tool and/or environment, thus consisting the initial approach to the system and/or problem definition (Figure 2).
: a) flow diagrams with arrows representing inputs/outputs to/from system components. These generally tend to be more user- friendly, and; b) causal loop diagrams where directed arrows are signed either positively (+) or negatively (-) depending on whether interconnected variables change in the same or opposite directions when they affect each other. Water needs Kremikovtzi mine mine water Clean water needs KP wasted total water Clean Water to KP from mine Kremikovtzi total waste water (red) KP waste water produced evaporation losses Pancherevo RES1 Clean water inflow to KP Inflow to Pancherevo drinking water Used water flow to KP Inflow series drinking water to KP <Time> Waste water % to WWTPI Delay buffer Buffer Kremikovtzi used water parameter (purple) Waste water flow from KP to WWT...
Conceptual models. Conceptual models are diagrams of key variables and interactions, representing the dynamic nature of a system, including interconnections, feedback loops and delays. Such graphical tools are generally transparent and easy to understand, especially for non-specialists. Establishing a conceptual model is a demanding task because the processes involved are dynamic, interdependent, complex and non-linear, and these processes may not be completely understood. Each model must be designed to answer specific questions, and should start by defining the system boundaries, the goal of the model and the key interactions. Only once this conceptual model is well defined should numerical modelling proceed. The use of a conceptual model leading to formal SDM development offers the advantage of being able to partition a very complex system into number smaller sub-systems describing different elements of the larger system, making the quantitative modelling process more manageable. Conceptual models can be developed for each sub-system, then linked together to form an overall model of the larger system under consideration. Conceptual models are generally represented as diagrams showing key system components interconnected with directed arrows. It can be drawn without being linked to a specific software tool and/or environment, thus consisting the initial approach to the system and/or problem definition (Figure 1). In SDM there exist two types of conceptual diagrams (Figure 2; Ford, 1999): a) flow diagrams with arrows representing inputs/outputs to/from system components. These generally tend to be more user-friendly, and;