## 4 Results  
In the hardware-based RoboCAR control system of Hanback Electronics Company in Korea, they need to have the software simulator of RoboCAR system to control remotely their hardware car, and then monitor their sensing data in real time as a training tool for education. Therefore, we developed a robot development system as a concept of simulation based on a virtual environment that deals an abstracted model with real hardware. In particular, the smart traffic control system in a smart city requires autonomous traffic control for people and vehicles. To achieve this, sophisticated and standardized software development is required. Therefore, many Korean software companies are doing their own research and development in their own way. We show a smart traffic control simulator in Figure 8. In a virtual environment, this tool can simulate a variety of environments and situations (camera simulation, traffic light control, multiple vehicle creation, and so on) before operating a real smart traffic control system. In addition, the tool can create virtual robot cars, and simulate them with simultaneously operating the real car in a real environment. The smart traffic control simulator controls simulated models through the center screen. They can make a new robot car model with the part modules on the left of the screen, and represent the location data of the property window on the right of the screen. Table 5 describes detailed components of the smart traffic control simulator. The smart traffic control simulator consists of a menu bar, shortcut icon bar, model view tool bar, simulation view tab, property window, and output window. Figure 8: Smart traffic control simulator. Figure 9 shows a test platform of a smart traffic system to test on a smart traffic control simulator. We published 'Evaluation of a Smart Traffic Light System with an IOT-based Connective Mechanism' to apply with a smart traffic control simulator to connect with the Internet of Things (IoT) technology [38]. With this, it is possible to extract the data needed to build an efficient and smart traffic signal mechanism. On the test platform with the simulator, the efficiency of smart traffic signals can be verified in a simulation environment. Figure 10 shows the code visualization of the smart traffic control simulator. This is the result of code visualization. In Figure 10, part 1 is the module that is inside the simulator package. Part 2 is the module that is defined out of the simulator. Part 3 indicates the highest score of strong coupling between modules. Part 4 indicates each score of coupling with external modules. Both _DirectionCtrl_ and _RobotModelingSimulationView_ are called from the _CarModule_ of part 5 with the red bolded arrows, which have strong couplings of modules among the visualization results. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Number** & **Name** & **Description** \\ \hline
1 & MenuBar & Provide functions related to simulation such as saving, \\  & & loading, starting, and stopping. \\ \hline
2 & Icon Bar & Frequent used icons among the functions in the menu bar. \\ \hline
3 & Model View & Assemble with part modules of the simulation view. \\ \hline
4 & ToolBar & Provides tools for drawing robot models. \\ \hline
5 & Simulation View Tab & Manage multiple simulation views. \\ \hline
6 & Simulation View & Screen for running a robot model. \\ \hline
7 & Property & Manage properties of robot model. \\ \hline
8 & Output & Output the robot modeling and debugging results. \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Components of the smart traffic control simulator. Figure 9: Test platform of a smart traffic light system. For example, _DirectionCtrl_ of the red box in part 1 has (8, 260, and 5), where 8 means the number of calls, 260 means execution time [ms], and 5 means the number of performance degradation factors.