Search results

Traffic density is one of the most important parameters to consider in the traffic operation field. Owing to limited data sources, traditional methods cannot extract traffic density directly. In the vehicular ad hoc network (VANET) environment, the vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) interaction technologies create better conditions for collecting the whole time-space and refined traffic data, which provides a new approach to solving this problem.

On that basis, a real-time traffic density extraction method has been proposed, including lane density, segment density and network density. Meanwhile, using SUMO and OMNet++ as traffic simulator and network simulator, respectively, the Veins framework as middleware and the two-way coupling VANET simulation platform was constructed.

Based on the simulation platform, a simulated intersection in Shanghai was developed to investigate the adaptability of the model.

Most research studies use separate simulation methods, importing trace data obtained by using from the simulation software to the communication simulation software. In this paper, the tight coupling simulation method is applied. Using real-time data and history data, the research focuses on the establishment and validation of the traffic density extraction model.

The megaproject is a vital innovation ecosystem for participants engaging in technological adoption and integration to achieve project goals. The purpose of this paper is to examine how ecosystem captains build and operate a megaproject innovation ecosystem (MIE). To be more specific, we conducted an in-depth case study to identify the roles played by ecosystem captains in establishing and managing a megaproject innovation ecosystem.

Based on the Hong Kong-Zhuhai-Macau Bridge project, the data we collected range from 2010 to 2019 and include semi-structured interviews, informal conversations, and archival documents. We employed an inductive theory building approach to address our research question and analyzed our data using the coding process and Atlas.ti software.

We find that the ecosystem captains themselves are client organizations that have evolved with the ecosystem during four distinct yet inter-related phases. In addition, we find that the captains’ roles of the client organizations include two typical activities: ecosystem establishment and ecosystem collaboration. The ecosystem captains first frame problems, plan innovative activities, set rules, and select participants for the establishment of the ecosystem, and then orchestrate resources, buffer conflicts, incorporate innovative networks, and cultivate an innovation culture to create a collaborative ecosystem.

This study proposes a theoretical framework showing how ecosystem captains engage in MIE to manage innovative activities during different stages. It highlights the importance of captainship roles in client organizations in a megaproject.