Separated or integrated? the optimal matching mode in ride-hailing platforms with autonomous vehicles

The impact of autonomous vehicles on ride-hailing platforms with strategic human drivers

Most optimizations for trajectory planning with autonomous vehicles first decouple the lateral-longitudinal-time problem, transforming decision-making into a matter of limited choices. Potential alternatives that can lead to better performance have been ruled out once the trajectory has been predefined in spatial dimensions, such as path optimization. This paper mainly draws on the optimization method from the Apollo EM Motion Planner and proposes a simplified, graph-search based approach by putting the decision-making process as well as the speed optimization first. The approach mainly concentrates on multilane scenarios with high-speed autonomous driving in a two-layer manner. The first layer is the combination of decision-making and longitudinal planning, whose purpose is to provide optional speed profiles under different target distances and local decisions. The second layer supplements the lateral planning process depending on every achievable speed profile. Dynamic programming is selected in both two layers to search the best discrete sampling path, because the optimization mode with longitudinal priority reduces pruning effort of dynamic programming in the second layer. Compared with the EM Motion Planner, this approach makes up the possible loss with different target distances and local decisions, it also simplifies the detection of obstacles. In the simulation, the capabilities of the approach are testified under a high-speed, multilane scenario with obstacle vehicles with random speed.

Fluorescence imaging using radiofrequency-tagged emission (FIRE) is an emerging technique that enables higher imaging speed (namely, temporal resolution) in fluorescence microscopy compared to conventional fluorescence imaging techniques such as confocal microscopy and wide-field microscopy. It works based on the principle that it uses multiple intensity-modulated fields in an interferometric setup as excitation fields and applies frequency-division multiplexing to fluorescence signals. Unfortunately, despite its high potential, FIRE has limited imaging speed due to two practical limitations: signal bandwidth and signal detection efficiency. The signal bandwidth is limited by that of an acousto-optic deflector (AOD) employed in the setup, which is typically 100-200 MHz for the spectral range of fluorescence excitation (400-600 nm). The signal detection efficiency is limited by poor spatial mode-matching between two interfering fields to produce a modulated excitation field. Here we present a method to overcome these limitations and thus to achieve higher imaging speed than the prior version of FIRE. Our method achieves an increase in signal bandwidth by a factor of two and nearly optimal mode matching, which enables the imaging speed limited by the lifetime of the target fluorophore rather than the imaging system itself. The higher bandwidth and better signal detection efficiency work synergistically because higher bandwidth requires higher signal levels to avoid the contribution of shot noise and amplifier noise to the fluorescence signal. Due to its unprecedentedly high-speed performance, our method has a wide variety of applications in cancer detection, drug discovery, and regenerative medicine.

In order to address that current coordinated power supply research of distribution networks only considers single voltage level, coordinated power supply modes for multi-voltage distribution networks considering 110kV lines are established, and optimized based on economic performance and load supply capability. Firstly, based on the connection modes of distribution lines, interconnecting structure of substations and allocation of transformers, the typical power supply modes for medium-voltage distribution networks are constructed, and the mode attributes are calculated. Then, based on economic analysis and load supply capability, the optimal match mode and mode parameters for network/substation on different voltage levels are selected with the objective of minimizing load supply cost. Finally, 110kV distribution networks are introduced, and the power supply relations between 110kV lines and 110kV transformers are studied, and the optimal coordinated power supply mode for multi-voltage distribution networks considering 110kV lines is obtained, which can provide guidance for the coordination and planning of regional distribution networks.

Fusion splicing small-core photonic crystal fibers and single-mode fibers by controlled air hole collapse