Recognition of Crowd Behavior from Mobile Sensors with Pattern Analysis and Graph Clustering Methods

Mobile on-body sensing has distinct advantages for the analysis and understanding of crowd dynamics: sensing is not geographically restricted to a specific instrumented area, mobile phones offer on-body sensing and they are already deployed on a large scale, and the rich sets of sensors they contain allows one to characterize the behavior of users through pattern recognition techniques. In this paper we present a methodological framework for the machine recognition of crowd behavior from on-body sensors, such as those in mobile phones. The recognition of crowd behaviors opens the way to the acquisition of large-scale datasets for the analysis and understanding of crowd dynamics. It has also practical safety applications by providing improved crowd situational awareness in cases of emergency. The framework comprises: behavioral recognition with the user's mobile device, pairwise analyses of the activity relatedness of two users, and graph clustering in order to uncover globally, which users participate in a given crowd behavior. We illustrate this framework for the identification of groups of persons walking, using empirically collected data. We discuss the challenges and research avenues for theoretical and applied mathematics arising from the mobile sensing of crowd behaviors

Comparative Study of Various Crowd Detection and Classification Methods for Safety Control System

A crowd is a distinct collection of people or anything that is involved in community or society. The phenomenon of a crowd is fairly well known in a wide range of academic fields, including sociology, civil engineering, and physics, amongst others. At this point in time, it has developed into the most active-oriented research and fashionable issue in the field of computer vision. Pre-processing, object detection, and event or behavior identification are the three stages of processing that are traditionally included in crowd analysis. These stages are pre-processing, object detection, and event recognition. Pre-processing, object detection, and event or behaviour identification are the three stages of processing that are traditionally included in crowd analysis. These stages are pre-processing, object detection, and event recognition. This study gives a model of crowd analysis as well as a taxonomy of the most prevalent method to crowd analysis. It may be helpful to researchers and would serve as a good introduction connected to the area of work that has been conducted

Stock Market Speculation: Spontaneous Symmetry Breaking of Economic Valuation

Firm foundation theory estimates a security's firm fundamental value based on four determinants: expected growth rate, expected dividend payout, the market interest rate and the degree of risk. In contrast, other views of decision-making in the stock market, using alternatives such as human psychology and behavior, bounded rationality, agent-based modeling and evolutionary game theory, expound that speculative and crowd behavior of investors may play a major role in shaping market prices. Here, we propose that the two views refer to two classes of companies connected through a ``phase transition''. Our theory is based on 1) the identification of the fundamental parity symmetry of prices ($p \to -p$), which results from the relative direction of payment flux compared to commodity flux and 2) the observation that a company's risk-adjusted growth rate discounted by the market interest rate behaves as a control parameter for the observable price. We find a critical value of this control parameter at which a spontaneous symmetry-breaking of prices occurs, leading to a spontaneous valuation in absence of earnings, similarly to the emergence of a spontaneous magnetization in Ising models in absence of a magnetic field. The low growth rate phase is described by the firm foundation theory while the large growth rate phase is the regime of speculation and crowd behavior. In practice, while large ``finite-time horizon'' effects round off the predicted singularities, our symmetry-breaking speculation theory accounts for the apparent over-pricing and the high volatility of fast growing companies on the stock markets.Comment: 23 pages, 10 figure

System Identification for the design of behavioral controllers in crowd evacuations

Behavioral modification using active instructions is a promising interventional method to optimize crowd evacuations. However, existing research efforts have been more focused on eliciting general principles of optimal behavior than providing explicit mechanisms to dynamically induce the desired behaviors, which could be claimed as a significant knowledge gap in crowd evacuation optimization. In particular, we propose using dynamic distancekeeping instructions to regulate pedestrian flows and improve safety and evacuation time. We investigate the viability of using Model Predictive Control (MPC) techniques to develop a behavioral controller that obtains the optimal distance-keeping instructions to modulate the pedestrian density at bottlenecks. System Identification is proposed as a general methodology to model crowd dynamics and build prediction models. Thus, for a testbed evacuation scenario and input?output data generated from designed microscopic simulations, we estimate a linear AutoRegressive eXogenous model (ARX), which is used as the prediction model in the MPC controller. A microscopic simulation framework is used to validate the proposal that embeds the designed MPC controller, tuned and refined in closed-loop using the ARX model as the Plant model. As a significant contribution, the proposed combination of MPC control and System Identification to model crowd dynamics appears ideally suited to develop realistic and practical control systems for controlling crowd motion. The flexibility of MPC control technology to impose constraints on control variables and include different disturbance models in the prediction model has confirmed its suitability in the design of behavioral controllers in crowd evacuations. We found that an adequate selection of output disturbance models in the predictor is critical in the type of responses given by the controller. Interestingly, it is expected that this proposal can be extended to different evacuation scenarios, control variables, control systems, and multiple-input multiple-output control structures.Ministerio de Economía y Competitivida

Exploring Crowd Management and Evacuation Strategies using Microscopic Pedestrian Simulation: A Case Study of Souq Waqif

Safe egress plans are critical for crowd evacuation at touristic attractions, particularly during special events, as visitors are often unaware of their options. Identification of bottlenecks in the walking spaces are vital for the development of safe and efficient crowd management and evacuation plans. This paper aims to explore crowd management and evacuation strategies for pedestrian egress flow in Souq Waqif, which is a famous touristic attraction in Doha, under varying crowd demand conditions. PTV Viswalk pedestrian simulation tool was used to evaluate crowd evacuation strategies and identify potential bottlenecks during the egress of crowds. Several guided and unguided evacuation scenarios were developed to understand the egress patterns to the allocated assembly areas inside the Souq. The crowd demands and densities were estimated using publicly available data. Eight major locations were identified as the bottleneck during the simulation. Simulation outcomes highlighted that the current evacuation plans and assembly locations are inadequate in providing safe evacuation routes. However, guided scenarios reduced evacuation times considerably when compared to unguided scenarios, particularly when the demand is high. A sensitivity analysis was also conducted to identify the effect of variations in walking behavior parameters in the simulation model. Variations in the walking behavior parameters changed the evacuation times considerably. Thus, proper calibration of walking behavior parameters considering local conditions could improve simulation accuracy. This study helps to identify probable bottlenecks and their characteristics that could help policymakers to assess the effectiveness of evacuation plans and crowd management strategies for crowd safety

Peer crowd-based targeting in E-cigarette advertisements: a qualitative study to inform counter-marketing.

BACKGROUND:Cigarette lifestyle marketing with psychographic targeting has been well documented, but few studies address non-cigarette tobacco products. This study examined how young adults respond to e-cigarette advertisements featuring diverse peer crowds - peer groups with shared identities and lifestyles - to inform tobacco counter-marketing design. METHODS:Fifty-nine young adult tobacco users in California participated in interviews and viewed four to five e-cigarette advertisements that featured characters from various peer crowd groups. For each participant, half of the advertisements they viewed showed characters from the same peer crowd as their own, and the other half of the advertisements featured characters from a different peer crowd. Advertisements were presented in random order. Questions probed what types of cues are noticed in the advertisements, and whether and how much participants liked or disliked the advertisements. RESULTS:Results suggest that participants liked and provided richer descriptions of characters and social situations in the advertisements featuring their own peer crowd more than the advertisements featuring a different peer crowd. Mismatching age or device type was also noted: participants reported advertisements showing older adults were not intended for them. Participants who used larger vaporizers tended to dislike cigalike advertisements even if they featured a matching peer crowd. CONCLUSION:Peer crowd and lifestyle cues, age and device type are all salient features of e-cigarette advertising for young adults. Similarly, educational campaigns about e-cigarettes should employ peer crowd-based targeting to engage young adults, though messages should be carefully tested to ensure authentic and realistic portrayals