# Trust Model of Privacy-Concerned, Emotionally Aware Agents in a Cooperative Logistics Problem
## 6 Problem Definition in the GAMA Platform  
In the simulations, carrier agents (with different initial random locations, personalities and assigned packages) move and interact in an abstract environment represented by a grid. At the beginning of the simulation, several boxes appear with random destinations and assignments to carriers. Initially and in any time, an agent may concurrently have several boxes to move (requiring the cooperation of other agents to satisfy all moving goals in time). The simulation ends when all packages have reached their destinations.  
According to this problem definition, agents feel different emotions when they meet each other and when they succeed or fail in moving a box. We assume that agents perceive the gaits of the other agents when they meet in the same location. Additionally, we assume the ability of agents to identify which boxes and cells cause personal privacy concerns.  
In order to implement our trust model, we used the GAMA agent platform [47] version 1.8.2, which is an open-source, FIPA-compliant software that includes the possibility of using the BDI paradigm for reasoning [48]. GAMA allows for large-scale simulations and integrates geographic information system (GIS) data [49]. The GMA agent also includes an extension that links norms with emotions [50].  
The parameters of the simulation define the setup of the problem, as shown in Figure 3 and listed below jointly with the values used in the experiment:  
* Whether to include trust in the simulation or not (variable: true or false);
* Whether to include emotions in the simulation or not (variable: true or false);
* Number of packages (fixed at 15);
* Number of carrier agents (fixed at 15);
* Percentage of initially idle carrier agents (variable: 0%, 20%, 40%, 60% or 80%);
* Size of the square grid, in number of cells (fixed at 30);
* Probability of a cell/box being private (variable: 0.0, 0.2, 0.4, 0.6 or 0.8);
* Probability of being neurotic (fixed at 33%);
* Probability of being psychotic (fixed at 33%);
* Penalty associated with privacy disclosure (fixed at 2.0);
* Reward for reaching the target in time (fixed at 1.0);
* Penalty for a delay in reaching the target (fixed at 2.0);
* Basic trust threshold to cooperate (fixed at 0.5);
* Initial trust in an unknown agent (fixed at 0.5).  
Figure 2: Sequentially linked FIPA CFP interaction protocol for a given task several times.  
Agents are represented as rectangles with their corresponding IDs inside in a grid of cells and colored in blue when they are idle, whereas the destinations of the boxes to be moved according to the original assignment are represented by green-colored circles containing the ID of the assigned carrier, as shown in Figure 4. Once the agents perceive the packages and start moving, the destinations of boxes to be moved by other agents that differ from the original assignment are represented by yellow-colored circles containing the ID of the currently moving carrier, and the carriers moving a package are represented by black-colored squares containing their ID and cells in which two or more agents meet are represented as red-colored squares, as shown in Figure 5.  
Figure 4: Initial situation in a scenario in which carrier agents move to the destinations of their boxes.  
Figure 3: Parameter definition in the CUI simulation.