## 2 Theoretical Analysis and Fabrication of Lens and Heatsink for the Seaport Luminaire
### Theoretical Analysis of LED and Conventional HID Luminaires in Seaport Application  
To verify the feasibility of the developed prototype LED seaport luminaire in seaport lighting application, the light distribution characteristics of the fabricated prototype LED seaport luminaire with conventional HID seaport luminaires were analyzed using Relux software [27,28]. In this analysis, for the conventional HID luminaires, a metal halide luminaire with a rated power of 1000 W and a high-pressure sodium luminaire with a rated power of 1000 W were considered, even though the rated power of the prototype of the LED luminaire is 500 W. In the simulation, 48 luminaires for the single high mask at each corner (192 luminaries in total) were considered for each type of luminaire. The simulation results of light distribution for each type of luminaire are shown in Figure 7. Among these three kinds of luminaire, it shows uniform optical distribution characteristics in the order of the fabricated prototype LED luminaire, the commercial high-pressure sodium luminaire, and the metal halide luminaire. Based on these theoretical analyses, the overall uniformity for three kinds of luminaires was derived as summarized in Table 5. Only LED luminaires satisfied the overall uniformity of 0.7 or more required by seaport lighting application, even though the metal halide luminaire shows the largest average illuminance. Actual Measurements of LED Seaport Luminaire and Conventional HID Seaport Luminaires in Seaport Installation  
To measure the actual optical performances of the developed prototype LED seaport luminaire, we set up a testbed at a real seaport with an installation of an LED luminaire and an HID luminaire. At the seaport area, a total of six sections with 56 measurements points were selected, as shown in Figure 8a, and illuminance sensors were installed at every one of the 56 measurement points to get the illuminance data, as shown in Figure 8b. Figure 7: Simulation results of light distribution considering real dimension (150 m \(\times\) 150 m) of seaport installation: commercial metal halide luminaire (**a**), commercial high-pressure sodium luminaire (**b**), and fabricated prototype LED luminaire (**c**). \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Parameter**} & \multicolumn{3}{c}{**TYPE of Luminaire**} \\ \cline{2-4}  & **Commercial Metal** & **Commercial High Pressure** & **Fabricated LED Luminaire** \\  & **Halide Luminaire** & **Sodium Luminaire** & **Fabricated LED Luminaire** \\ \hline Minimum illuminance & 29 k & 60 lx & 66 lx \\ Average illuminance & 65 lx & 108 lx & 92 lx \\ Overall uniformity & 0.44 & 0.56 & 0.72 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Simulation results of light distribution considering real dimensions (150 m \(\times\) 150 m) of seaport installation. The measured illuminance values for each measurement point were presented in Figure 8c for HID luminaires (1000 W HID luminaire \(\times\) 12 ea) and Figure 8d for LED luminaires (500 W LED luminaire \(\times\) 12 ea). Compared to the HID luminaire's case, the measured illuminance data of the LED luminaire show more uniformly distributed values at Sections 4-6. The measured average illuminance of the HID luminaire was about 54 lx, whereas the simulated value was 65 lx. In the case of the LED luminaire, the measured average illuminance was about 80 lx, whereas the simulated value was 92 lx. Thus, there is a 10 lx difference between the simulation and actual measurement. Simulated and measured values for average illuminance and overall uniformity are summarized in Table 6. \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Parameter**} & \multicolumn{2}{c}{**Commercial Metal Halide Luminaire**} & \multicolumn{2}{c}{**Fabricated LED Luminaire**} \\ \cline{2-4}  & **Simulated Value** & **Measured Value** & **Simulated Value** & **Measured Value** \\ \hline Average illuminance & 65 lx & 54 lx & 92 lx & 80 lx \\ Overall uniformity & 0.44 & 0.3 & 0.72 & 0.5 \\ \hline \hline \end{tabular}
\end{table}