Figures (7)  Tables (4)

    • Figure 1. 

      Structure diagram of self-powered wireless sensor network monitoring system.

    • Figure 2. 

      Flow chart of the sensor node.

    • Figure 3. 

      Main factors affecting the development of tennis in colleges and universities.

    • Figure 4. 

      Changes in the proportion of reasons for not playing tennis.

    • Figure 5. 

      Energy collection rate of solar nodes over time in one day.

    • Figure 6. 

      Comparison of packet loss rate.

    • Figure 7. 

      Monitoring chart of charge and discharge of battery pack.

    • Serial number Information source Percentage
      1 TV news 57%
      2 Teachers and classmates 45%
      3 Network 37%
      4 Advertising 27%

      Table 1. 

      Information sources of tennis knowledge of college students.

    • Serial number Influencing factor Percentage
      1 Site facilities 76.2%
      2 Campus tennis culture atmosphere 51.3%
      3 Tennis organization and management 38.4%
      4 College students' sports consumption consciousness 28.2%

      Table 2. 

      Influencing factors of college students' participation in tennis.

    • Number of tennis courts Percentage of colleges and universities
      > 8 21.5%
      4−8 51.3%
      < 4 27.3%

      Table 3. 

      Tennis courts owned by a school.

    • Hourly charge (CNY) Percentage
      < 10 10.7%
      10−20 46.4%
      20−40 28.7%
      > 40 13.8%

      Table 4. 

      Tennis court charges of a school.