Modeling the impact of latent driving patterns on traffic safety using mobile sensor data

2017 ◽  
Vol 107 ◽  
pp. 92-101 ◽  
Author(s):  
Rajesh Paleti ◽  
Olcay Sahin ◽  
Mecit Cetin
Author(s):  
C. Kehl ◽  
S. J. Buckley ◽  
R. L. Gawthorpe ◽  
I. Viola ◽  
J. A. Howell

Adding supplementary texture and 2D image-based annotations to 3D surface models is a useful next step for domain specialists to make use of photorealistic products of laser scanning and photogrammetry. This requires a registration between the new camera imagery and the model geometry to be solved, which can be a time-consuming task without appropriate automation. The increasing availability of photorealistic models, coupled with the proliferation of mobile devices, gives users the possibility to complement their models in real time. Modern mobile devices deliver digital photographs of increasing quality, as well as on-board sensor data, which can be used as input for practical and automatic camera registration procedures. Their familiar user interface also improves manual registration procedures. This paper introduces a fully automatic pose estimation method using the on-board sensor data for initial exterior orientation, and feature matching between an acquired photograph and a synthesised rendering of the orientated 3D scene as input for fine alignment. The paper also introduces a user-friendly manual camera registration- and pose estimation interface for mobile devices, based on existing surface geometry and numerical optimisation methods. The article further assesses the automatic algorithm’s accuracy compared to traditional methods, and the impact of computational- and environmental parameters. Experiments using urban and geological case studies show a significant sensitivity of the automatic procedure to the quality of the initial mobile sensor values. Changing natural lighting conditions remain a challenge for automatic pose estimation techniques, although progress is presented here. Finally, the automatically-registered mobile images are used as the basis for adding user annotations to the input textured model.


Author(s):  
C. Kehl ◽  
S. J. Buckley ◽  
R. L. Gawthorpe ◽  
I. Viola ◽  
J. A. Howell

Adding supplementary texture and 2D image-based annotations to 3D surface models is a useful next step for domain specialists to make use of photorealistic products of laser scanning and photogrammetry. This requires a registration between the new camera imagery and the model geometry to be solved, which can be a time-consuming task without appropriate automation. The increasing availability of photorealistic models, coupled with the proliferation of mobile devices, gives users the possibility to complement their models in real time. Modern mobile devices deliver digital photographs of increasing quality, as well as on-board sensor data, which can be used as input for practical and automatic camera registration procedures. Their familiar user interface also improves manual registration procedures. This paper introduces a fully automatic pose estimation method using the on-board sensor data for initial exterior orientation, and feature matching between an acquired photograph and a synthesised rendering of the orientated 3D scene as input for fine alignment. The paper also introduces a user-friendly manual camera registration- and pose estimation interface for mobile devices, based on existing surface geometry and numerical optimisation methods. The article further assesses the automatic algorithm’s accuracy compared to traditional methods, and the impact of computational- and environmental parameters. Experiments using urban and geological case studies show a significant sensitivity of the automatic procedure to the quality of the initial mobile sensor values. Changing natural lighting conditions remain a challenge for automatic pose estimation techniques, although progress is presented here. Finally, the automatically-registered mobile images are used as the basis for adding user annotations to the input textured model.


Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 539
Author(s):  
Saleh Seyedzadeh ◽  
Andrew Agapiou ◽  
Majid Moghaddasi ◽  
Milan Dado ◽  
Ivan Glesk

The growing demand for extensive and reliable structural health monitoring resulted in the development of advanced optical sensing systems (OSS) that in conjunction with wireless optical networks (WON) are capable of extending the reach of optical sensing to places where fibre provision is not feasible. To support this effort, the paper proposes a new type of a variable weight code called multiweight zero cross-correlation (MW-ZCC) code for its application in wireless optical networks based optical code division multiple access (WON-OCDMA). The code provides improved quality of service (QoS) and better support for simultaneous transmission of video surveillance, comms and sensor data by reducing the impact of multiple access interference (MAI). The MW-ZCC code’s power of two code-weight properties provide enhanced support for the needed service differentiation provisioning. The performance of this novel code has been studied by simulations. This investigation revealed that for a minimum allowable bit error rate of 10−3, 10−9 and 10−12 when supporting triple-play services (sensing, datacomms and video surveillance, respectively), the proposed WON-OCDMA using MW-ZCC codes could support up to 32 simultaneous services over transmission distances up to 32 km in the presence of moderate atmospheric turbulence.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lei Lin ◽  
Feng Shi ◽  
Weizi Li

AbstractCOVID-19 has affected every sector of our society, among which human mobility is taking a dramatic change due to quarantine and social distancing. We investigate the impact of the pandemic and subsequent mobility changes on road traffic safety. Using traffic accident data from the city of Los Angeles and New York City, we find that the impact is not merely a blunt reduction in traffic and accidents; rather, (1) the proportion of accidents unexpectedly increases for “Hispanic” and “Male” groups; (2) the “hot spots” of accidents have shifted in both time and space and are likely moved from higher-income areas (e.g., Hollywood and Lower Manhattan) to lower-income areas (e.g., southern LA and southern Brooklyn); (3) the severity level of accidents decreases with the number of accidents regardless of transportation modes. Understanding those variations of traffic accidents not only sheds a light on the heterogeneous impact of COVID-19 across demographic and geographic factors, but also helps policymakers and planners design more effective safety policies and interventions during critical conditions such as the pandemic.


2021 ◽  
pp. 43-48
Author(s):  

Improving the system of preventive measures aimed at reducing the severity of the consequences of road accidents is an urgent task. Road deaths are constantly increasing and there is a need for a comprehensive approach to creating safe road conditions. The purpose of this study is to analyze the promising designs of road barriers designed to prevent uncontrolled exit of vehicles from the roadway of the highway and to develop the design of energy-absorbing fencing. Barrier barriers must not only be safe for road users, but must also ensure their safety, as well as preserve the elements after hitting the fence. Analytical studies have shown that in order to reduce mechanical damage to vehicles and reduce the severity of injuries to the driver and passengers, it is necessary to develop a road fence design that allows you to extinguish the impact energy at the moment of contact between the car and the fence. Keywords: fencing, barrier, safety, traffic accident


Author(s):  
Juyuan Yin ◽  
Jian Sun ◽  
Keshuang Tang

Queue length estimation is of great importance for signal performance measures and signal optimization. With the development of connected vehicle technology and mobile internet technology, using mobile sensor data instead of fixed detector data to estimate queue length has become a significant research topic. This study proposes a queue length estimation method using low-penetration mobile sensor data as the only input. The proposed method is based on the combination of Kalman Filtering and shockwave theory. The critical points are identified from raw spatiotemporal points and allocated to different cycles for subsequent estimation. To apply the Kalman Filter, a state-space model with two state variables and the system noise determined by queue-forming acceleration is established, which can characterize the stochastic property of queue forming. The Kalman Filter with joining points as measurement input recursively estimates real-time queue lengths; on the other hand, queue-discharging waves are estimated with a line fitted to leaving points. By calculating the crossing point of the queue-forming wave and the queue-discharging wave of a cycle, the maximum queue length is also estimated. A case study with DiDi mobile sensor data and ground truth maximum queue lengths at Huanggang-Fuzhong intersection, Shenzhen, China, shows that the mean absolute percentage error is only 11.2%. Moreover, the sensitivity analysis shows that the proposed estimation method achieves much better performance than the classical linear regression method, especially in extremely low penetration rates.


2016 ◽  
Vol 19 (2) ◽  
pp. 317-325 ◽  
Author(s):  
Bruna Maria Bueno Barbosa ◽  
Rosane Aparecida Monteiro ◽  
Lucas Françolin Sparano ◽  
Rodolfo Fabiano Niz Bareiro ◽  
Afonso Dinis Costa Passos ◽  
...  

ABSTRACT: Objective: It was to identify trends of traumatic and non-traumatic causes of lower limb amputations, as well as the role played by population aging, traffic violence increase, public health policy of diabetes control program and drivers anti-alcohol laws on these amputations. Method: Hospitalization data recorded in the discharge forms of 32 hospitals located in the region of Ribeirão Preto, Brazil, from 1985 to 2008 were analyzed. Result: A total of 3,274 lower-limb amputations were analyzed, of which 95.2% were related to non-traumatic causes, mainly infectious and ischemic complications of diabetes mellitus. Cancer (2.8%) and congenital (1.3%) causes were included in this group. Only 4.8% were related to traumatic causes. Traumatic amputation average rate was 1.5 amputations in 100,000 habitants with a slight tendency of increase in the last 5 years. Non-traumatic causes showed an average rate of 30.0 amputations for 100,000 habitants and remained relatively constant during the whole period. Non-traumatic were much more predominant in patients older than 60 years and traumatic amputations occurred more frequently in patients younger than 39 years. Conclusion: The overall rates of amputation and the rates of traumatic and non-traumatic amputations remained nearly constant during the study period. The impact of diabetes control policies and the introduction of traffic safety laws could not be identified on the amputation rates.


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