65 research outputs found
CARPe Posterum: A Convolutional Approach for Real-time Pedestrian Path Prediction
Pedestrian path prediction is an essential topic in computer vision and video
understanding. Having insight into the movement of pedestrians is crucial for
ensuring safe operation in a variety of applications including autonomous
vehicles, social robots, and environmental monitoring. Current works in this
area utilize complex generative or recurrent methods to capture many possible
futures. However, despite the inherent real-time nature of predicting future
paths, little work has been done to explore accurate and computationally
efficient approaches for this task. To this end, we propose a convolutional
approach for real-time pedestrian path prediction, CARPe. It utilizes a
variation of Graph Isomorphism Networks in combination with an agile
convolutional neural network design to form a fast and accurate path prediction
approach. Notable results in both inference speed and prediction accuracy are
achieved, improving FPS considerably in comparison to current state-of-the-art
methods while delivering competitive accuracy on well-known path prediction
datasets.Comment: AAAI-21 Camera Read
A mathematical framework for modelling and evaluating natural gas pipeline networks under hydrogen injection
This article presents the framework of a mathematical formulation for modelling and evaluating natural gas pipeline networks under hydrogen injection. The model development is based on gas transport through pipelines and compressors which compensate for the pressure drops by implying mainly the mass and energy balances on the basic elements of the network. The model was initially implemented for natural gas transport and the principle of extension for hydrogen-natural gas mixtures is presented. The objective is the treatment of the classical fuel minimizing problem in compressor stations. The optimization procedure has been formulated by means of a nonlinear technique within the General Algebraic Modelling System (GAMS) environment. This work deals with the adaptation of the current transmission networks of natural gas to the transport of hydrogen-natural gas mixtures. More precisely, the quantitative amount of hydrogen that can be added to natural gas can be determined. The studied pipeline network,initially proposed by Abbaspour et al. (2005) is revisited here for the case of hydrogen-natural gas mixtures. Typical quantitative results are presented, showing that the addition of hydrogen to natural gas decreases significantly the transmitted power : the maximum fraction of hydrogen that can be added to natural gas is around 6 mass percent for this example
Optimization of gas transmission networks
The transport of large quantities of natural gas is carried out by pipelines. Typically, natural gas compressor stations are located at regular intervals to boost the pressure lost. Two main issues are generally highlighted when considering pipeline transmission networks, i.e., designing and operating a gas pipeline network. This work is intended to provide a MINLP formulation (mixed integer non linear programming) for modelling and optimizing gas pipelines networks and is applied to a series of case studies covering a range of significant problems. Typical problems in industrial scales for fuel consumption minimization serve as an illustration. Then, a methodology for gas pipeline design, involving capital cost as an optimization criterion is presented. Finally, a more prospective concern, dedicated to the transport of a mixture of natural gas-hydrogen mixture in a transition period towards the so-called predicted “hydrogen economy” is tackled
A Novel Neural Network Approach for Predicting the Arrival Time of Buses for Smart On-Demand Public Transit
Among the major public transportation systems in cities, bus transit has its
problems, including more accuracy and reliability when estimating the bus
arrival time for riders. This can lead to delays and decreased ridership,
especially in cities where public transportation is heavily relied upon. A
common issue is that the arrival times of buses do not match the schedules,
resulting in latency for fixed schedules. According to the study in this paper
on New York City bus data, there is an average delay of around eight minutes or
491 seconds mismatch between the bus arrivals and the actual scheduled time.
This research paper presents a novel AI-based data-driven approach for
estimating the arrival times of buses at each transit point (station). Our
approach is based on a fully connected neural network and can predict the
arrival time collectively across all bus lines in large metropolitan areas. Our
neural-net data-driven approach provides a new way to estimate the arrival time
of the buses, which can lead to a more efficient and smarter way to bring the
bus transit to the general public. Our evaluation of the network bus system
with more than 200 bus lines, and 2 million data points, demonstrates less than
40 seconds of estimated error for arrival times. The inference time per each
validation set data point is less than 0.006 ms
- …