## 3 Methodology
### Database  
This study selected the United States Patent and Trademark Office (USPTO) patent summary database due to its critical role as a repository of global innovation. As the world's largest and most important commercial market, the United States attracts a high volume of patent filings from both domestic and international entities seeking to secure intellectual property rights [15]. For instance, more than half of USPTO filings come from international assignees, who often prioritize the USPTO for their initial or subsequent filings to establish a strong market position and gain legal protection in the U.S. [16]. This international  
Figure 1: The methodological workflow. dimension makes the USPTO database a rich source of diverse and high-quality patent documents, representing innovative advancements across the selected technology domains. Table 1 summarizes the search keywords and provides examples of relevant and irrelevant topics retrieved for each technology domain. Some of the keywords utilize wildcard characters like \"*\" and \"?\" to instruct the search engine to retrieve documents containing word variations such as their plural form and those containing keywords that ignore word separators like dashes. \begin{table}
\begin{tabular}{c c c c} \hline
**Domain** & **Keywords** & **Examples of Relevant Topics** & **Examples of Irrelevant Topics** \\ \hline \multirow{8}{*}{SSB} & & Challenges and solutions to SSB design including resolving interfacial resistance, ionic conductivity, charge cycling stability, and energy density through new architectures, electrodes, electrolytes, and manufacturing strategies. & Designs focused on battery chargers, circuitry, parking optimization to access chargers, connectivity to chargers, cloud services to evaluate charging levels, overcharge prevention, charge scheduling strategies, and optimized route planning to access charger networks. \\ \cline{1-1}  & & Challenges and solutions to charge scheduling, charge station management, charging device controller, charging safety, fast charging, fuel integration, multiple vehicle charging, on-board chargers designs, power transfer efficiency, charge state monitoring, and temperature management. & Charge pricing strategies, marketing promotions, smart grid and energy storage conversion systems, locating charging facilities, robotic chargers, vehicle sharing management, hybrid-electric vehicles, solar chargers, vehicle-to-grid energy management, electric motor design, motor controller designs, and regenerative power management. \\ \hline \multirow{8}{*}{CV} & & Wireless communications methods, driving safety, navigation, condition monitoring, traffic signal adaptation, smart parking, multi-vehicle networking, vehicular management, cybersecurity, and vehicle computing resource optimization. & Traffic demand modeling, cloud service hosting, customized vehicle settings, road network mapping, driver distraction detection, garage door control, towed vehicles, trailer controls, overhead line system, in-vehicle networks, edge-computing, wired base stations, and vehicle tethered apparatus or trailers. \\ \hline \multirow{8}{*}{eVTOL} & & Adaptable systems like rotors and flaps, control enhancement, drag reduction, energy management, propulsion efficiency, safety enhancement, thermal management, and transition efficiency. & Refrigerated cargo bays, user interfaces, stress sensors, aircraft simulators, combustion engine cooling, airbag integration, image capturing, remote sensing, display devices, remote control, and aircraft headlamps. \\ \hline \multirow{2}{*}{LiDAR} & & \multirow{2}{*}{lidar, vehicle, distance, cost} & Beam generation, beam steering, cost or size reduction, field-of-view enhancement, and signal quality management. & Road signage mapping, camera integration, vehicle control, left-behind object recognition, drone-based remote sensing, and vehicle remote control. \\ \hline \end{tabular}
\end{table} 
Table 1: Search keywords and examples of relevant and irrelevant topics.