# Experiment Information System Based on an Online Virtual Laboratory
## 3 Results
### The Virtual Laboratory  
According to the system architecture of the virtual laboratory system, Figure 5 shows the typical process of a user performing experiments in the virtual experiment system. First, the user logs in from the website with a username and password. Different users have different permissions. Once opening an experiment, the user can build a new scene, using the existing components in the virtual experiment panel. Then the experiment plug-in encapsulates the user's request and the relevant data of the experiment, which are sent to the computing server through the data-exchange layer of the system. Subsequently, the computing server forwards the request to the specific computing node, to complete the calculation. Finally, the computed data are transmitted back to the experiment plug-in along the opposite data link direction, to display the result visually. Figure 6 presents some screenshots of the 3D-virtual laboratory with the student client. The image in Figure 5(a) is an example of the real experimental environment. The image in Figure 5(b) is of the classroom environment of the virtual laboratory. As an attempt and validation, the laboratory appearance, virtual characters, and other things unrelated to the real devices and authentic operation flows are cartoon-like, to test whether a cartoon-style can attract students more. The image in Figure 5(c) shows the browser of the virtual experimental equipment. Students can select and take experimental equipment in this interface. These devices have been implemented to be fully identical to their corresponding real devices. In order to completely reproduce the real digital circuit experimental process--that is, students operate the real devices, and observe the experimental response on the computer screen in real time, such as signal response, parameter debugging, and so on--our virtual experiment platform realizes the function of invoking the simulation software on the virtual computer without exiting from the 3D client and entering another software interface. The image in Figure 5(d) shows the computer screen of a virtual computer in the virtual laboratory, when the student is conducting an experiment. In this interface, students can call and utilize simulation software commonly used in electronic circuit experiments, such as EasyEDA and Multisim. The second part is the teacher web interface, in which teachers can set up and manage student accounts and view their behavior and performance in the virtual lab as well as add, modify, and delete experiments as required, and also teachers could provide real-time communication to students. The image in Figure 6(a) shows an example of a set of experimental arrangements, and the image Figure 6(b) shows an example of a circuit diagram being viewed. The experimental data can also be exported to the spreadsheet files as a measurement set which can be running separately. When students complete a task and the teacher finishes the scoring, the evaluation tool will automatically generate a personal summary report. Figure 5: A typical work process under the above architecture. Figure 6: Some screenshots of the student client of the 3D virtual laboratory. The above clients are finally supported by the computation module, which is composed of three separate servers, namely the data server, the web server, and the computing server. The data server is mainly responsible for user information management, such as login information and privilege control. Besides this, it also stores the data related to the relationships among the user accounts and the measured data in each experiment, and it provides a library of mathematical models for circuit-related calculations. The web server carries the resources of the site, including web pages, pictures, experimental plug-ins, and others. Meanwhile, it primarily responds to the requests from the 3D student clients and the teacher web interface through the feedback mechanism.