31 research outputs found
Investigation of Voronoi diagram based Direction Choices Using Uni- and Bi-directional Trajectory Data
In a crowd, individuals make different motion choices such as "moving to
destination", "following another pedestrian", and "making a detour". For the
sake of convenience, the three direction choices are respectively called
destination direction, following direction and detour direction in this paper.
Here, it is found that the featured direction choices could be inspired by the
shape characteristics of Voronoi diagram. To be specific, in the Voronoi cell
of a pedestrian, the direction to a Voronoi node is regarded as a potential
"detour" direction, and the direction perpendicular to a Voronoi link is
regarded as a potential "following" direction. A pedestrian generally owns
several alternative Voronoi nodes and Voronoi links in a Voronoi cell, and the
optimal detour and following direction are determined by considering related
factors such as deviation. Plus the destination direction which is directly
pointing to the destination, the three basic direction choices are defined in a
Voronoi cell. In order to evaluate the Voronoi diagram based basic directions,
the empirical trajectory data in both uni- and bi-directional flow experiments
are extracted. A time series method considering the step frequency is used to
reduce the original trajectories' swaying phenomena which might disturb the
recognition of actual forward direction. The deviations between the empirical
velocity direction and the basic directions are investigated, and each velocity
direction is classified into a basic direction or regarded as an inexplicable
direction according to the deviations. The analysis results show that each
basic direction could be a potential direction choice for a pedestrian. The
combination of the three basic directions could cover most empirical velocity
direction choices in both uni- and bi-directional flow experiments.Comment: 10pages, 12 figure
Experimental Investigation of Pedestrian Dynamics in Circle Antipode Experiments
To explore the pedestrian motion navigation and conflict reaction mechanisms in practice, we organized a series of circle antipode experiments. In the experiments, pedestrians are uniformly initialized on the circle and required to leave for their antipodal positions simultaneously. On the one hand, a conflicting area is naturally formulated in the center region due to the converged shortest routes, so the practical conflict avoidance behaviors can be fully explored. On the other hand, the symmetric experimental conditions of pedestrians, e.g., symmetric starting points, symmetric destination points, and symmetric surroundings, lay the foundation for further quantitative comparisons among participants. The pedestrian trajectories in the experiments are recognized and rotated, and several aspects, e.g., the trajectory space distribution, route length, travel time, velocity distribution, and time-series, are investigated. It is found that: (1) Pedestrians prefer the right-hand side during the experiments; (2) The route length follows a log-normal distribution, the route potential obeys an exponential distribution, and travel time as well as speed are normally distributed; (3) Taking the short routes unexpectedly cost pedestrians plenty of travel time, while detours seem to be time-saving
RIO: A Benchmark for Reasoning Intention-Oriented Objects in Open Environments
Intention-oriented object detection aims to detect desired objects based on
specific intentions or requirements. For instance, when we desire to "lie down
and rest", we instinctively seek out a suitable option such as a "bed" or a
"sofa" that can fulfill our needs. Previous work in this area is limited either
by the number of intention descriptions or by the affordance vocabulary
available for intention objects. These limitations make it challenging to
handle intentions in open environments effectively. To facilitate this
research, we construct a comprehensive dataset called Reasoning
Intention-Oriented Objects (RIO). In particular, RIO is specifically designed
to incorporate diverse real-world scenarios and a wide range of object
categories. It offers the following key features: 1) intention descriptions in
RIO are represented as natural sentences rather than a mere word or verb
phrase, making them more practical and meaningful; 2) the intention
descriptions are contextually relevant to the scene, enabling a broader range
of potential functionalities associated with the objects; 3) the dataset
comprises a total of 40,214 images and 130,585 intention-object pairs. With the
proposed RIO, we evaluate the ability of some existing models to reason
intention-oriented objects in open environments.Comment: NeurIPS 2023 D&B accepted. See our project page for more details:
https://reasonio.github.io
Optimal Bus-Bridging Service under a Metro Station Disruption
A station disruption is an abnormal operational situation that the entrance or exit gates of a metro station have to be closed for a certain of time due to an unexpected incident. The passengers’ travel behavioral responses to the alternative station disruption scenarios and the corresponding controlling strategies are complex and hard to capture. This can lead to the hardness of estimating the changes of the network-wide passenger demand, which is the basis of carrying out a response plan. This paper will establish a model to solve the metro station disruption problem by providing optimal additional bus-bridging services. Two main contributions are made: "mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"""mml:mo stretchy="false""("/mml:mo""mml:mn fontstyle="italic""1"/mml:mn""mml:mo stretchy="false"")"/mml:mo""/mml:math" a three-layer discrete choice behavior model is developed to analyze the dynamic passenger flow demand under station disruption; and "mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M2"""mml:mo stretchy="false""("/mml:mo""mml:mn fontstyle="italic""2"/mml:mn""mml:mo stretchy="false"")"/mml:mo""/mml:math" an integrated algorithm is designed to manage and control the station disruption crisis by providing additional bus-bridging services with the objective of minimizing the total travel time of affected passengers and the operating cost of bridging-buses. Besides, the multimodal transport modes, including metro, bridging-bus, shared-bike, and taxi, are considered as passengers’ alternative choices in face of the station disruption. A numerical study based on the Beijing metro network shows that additional bus-bridging services can significantly eliminate the negative impact of the station disruption.
Document type: Articl
Deregulation of DUX4 and ERG in acute lymphoblastic leukemia
Chromosomal rearrangements deregulating hematopoietic transcription factors are common in acute lymphoblastic leukemia (ALL).1,2 Here, we show that deregulation of the homeobox transcription factor gene DUX4 and the ETS transcription factor gene ERG are hallmarks of a subtype of B-progenitor ALL that comprises up to 7% of B-ALL. DUX4 rearrangement and overexpression was present in all cases, and was accompanied by transcriptional deregulation of ERG, expression of a novel ERG isoform, ERGalt, and frequent ERG deletion. ERGalt utilizes a non-canonical first exon whose transcription was initiated by DUX4 binding. ERGalt retains the DNA-binding and transactivating domains of ERG, but inhibits wild-type ERG transcriptional activity and is transforming. These results illustrate a unique paradigm of transcription factor deregulation in leukemia, in which DUX4 deregulation results in loss-of-function of ERG, either by deletion or induction of expression of an isoform that is a dominant negative inhibitor of wild type ERG function
Modeling pedestrian behaviors of boarding and alighting dynamics in urban railway stations
Boarding and alighting process is the most complicated behaviour at urban railway stations, and significantly affects the service level and evacuation capacities of stations. This paper quantitatively discusses the individual and group behavioural characteristics of both boarding and alighting passengers. The time headways are extracted from surveillance videos. Based on the data analysis results, an improved cellular automata model is proposed to describe the microscopic dynamics of the boarding and alighting process. In this model, three categories of floor fields are defined to describe passenger behaviour. The number of alighting passengers is included to quantitatively describe the boarding and alighting pattern. The time headway is also used to define the following behaviour with leaders. The model is validated and calibrated from several aspects by real data. The proposed model comprehensively reveals the boarding and alighting dynamics, and it can potentially be used to make crowd management in subway stations
Trip planning for a mobility-as-a-service system: Integrating metros and shared autonomous vehicles
Mobility as a service (MaaS) integrates various transport modes into an on-demand and real-time platform, providing door-to-door service, and has received extensive attention. For MaaS, personalized trip planning is important but intractable. In this paper, we present a two-phase decision-support optimization framework for the problem of a MaaS system incorporating metros and shared autonomous vehicles (SAVs). First, a mixed integer programming model is proposed to optimize the routes of heterogeneous travelers considering five transport mode combinations, in which SAVs are regarded as not only a first- and last-mile connector to the metro but also a competitor. Next, the scheduling of SAVs and departure time of each traveler is determined with the purpose of minimizing the SAV operation cost. To apply the proposed framework to scenarios with real-time requests, we adopt the rolling horizon solution method, which includes four sub-modules. The method is evaluated on the Sioux Falls network, and the experimental results show that travelers become more sensitive to the mode choice as the additional time of the metro increases. In addition, the connectivity of the metro network has a considerable influence on the relationship between the metro and SAVs. The methodology can be useful for the trip planning of other transport mode combinations