The calculation of speed prediction equations has been the subject of numerous researches in the past. The majority of them present models to predict free-flow speed in terms of the road geometry at the curved road se...The calculation of speed prediction equations has been the subject of numerous researches in the past. The majority of them present models to predict free-flow speed in terms of the road geometry at the curved road sections and more specifically in terms of the radiuses of the curves. Common characteristic is that none of them approaches the speed behavior of motorcycles since they are excluded from the datasets of the various studies. Instead, the models usually predict operating speed for other vehicle types such as passenger cars, vans, pickups and trucks. The present paper aims to cover this gap by developing speed prediction equations for motorcycles. For this purpose a new methodology is proposed while field measurements were carried out in order to obtain an adequate dataset of free-flow speeds along the curved sections of three different two lane rural roads. The aforementioned field measurements were conducted by two participants incorporating various road conditions (e.g. light conditions, experience level, familiarity with the routes). The ultimate target was the development of speed prediction equations by calculating the optimum regression curves between the curve radius’ and the corresponding velocities for the different road conditions. The research revealed that the proposed methodology could be used as a very useful tool to investigate motorcyclists’ behavior at curved road sections. Moreover it was feasible to draw conclusions correlating the speed adjustment with the various driving conditions.展开更多
Coherent detection measures both the amplitude and phase of pulsed terahertz(THz)waves simultaneously,forming the foundation for THz time-domain spectroscopy(THz-TDS).This technique has become increasingly prominent i...Coherent detection measures both the amplitude and phase of pulsed terahertz(THz)waves simultaneously,forming the foundation for THz time-domain spectroscopy(THz-TDS).This technique has become increasingly prominent in the fields of physics and materials science,allowing researchers to investigate the dynamic properties of various dielectric materials within the 0.1 to 10 THz frequency range,which is previously a challenging spectrum to access.This paper reviews recent advancements and the challenges faced by commonly used coherent detectors in THz-TDS.Our discussion emphasizes the potential for new discoveries in THz photonics and highlights the crucial role of coherent detection in the study of laser-matter interactions.展开更多
文摘The calculation of speed prediction equations has been the subject of numerous researches in the past. The majority of them present models to predict free-flow speed in terms of the road geometry at the curved road sections and more specifically in terms of the radiuses of the curves. Common characteristic is that none of them approaches the speed behavior of motorcycles since they are excluded from the datasets of the various studies. Instead, the models usually predict operating speed for other vehicle types such as passenger cars, vans, pickups and trucks. The present paper aims to cover this gap by developing speed prediction equations for motorcycles. For this purpose a new methodology is proposed while field measurements were carried out in order to obtain an adequate dataset of free-flow speeds along the curved sections of three different two lane rural roads. The aforementioned field measurements were conducted by two participants incorporating various road conditions (e.g. light conditions, experience level, familiarity with the routes). The ultimate target was the development of speed prediction equations by calculating the optimum regression curves between the curve radius’ and the corresponding velocities for the different road conditions. The research revealed that the proposed methodology could be used as a very useful tool to investigate motorcyclists’ behavior at curved road sections. Moreover it was feasible to draw conclusions correlating the speed adjustment with the various driving conditions.
基金supported by grants from the National Natural Science Foundation of China(12074272)the R&D Program of Beijing Municipal Education Commission(KZ20231002825)the Youth Beijing Scholar Program administered by the Beijing Government.
文摘Coherent detection measures both the amplitude and phase of pulsed terahertz(THz)waves simultaneously,forming the foundation for THz time-domain spectroscopy(THz-TDS).This technique has become increasingly prominent in the fields of physics and materials science,allowing researchers to investigate the dynamic properties of various dielectric materials within the 0.1 to 10 THz frequency range,which is previously a challenging spectrum to access.This paper reviews recent advancements and the challenges faced by commonly used coherent detectors in THz-TDS.Our discussion emphasizes the potential for new discoveries in THz photonics and highlights the crucial role of coherent detection in the study of laser-matter interactions.
