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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Crowd modeling for surveillance. / CUHK electronic theses & dissertations collection

January 2008 (has links)
Anti-Terrorism has been a global issue and video surveillance has become increasingly popular in public places e.g. banks, airports, public squares, casinos, etc. However, when encountered with the crowd environment, conventional surveillance technologies will have difficulties in understanding human behaviors in crowded environment. / Firstly, I developed a learning-based algorithm for people counting task in crowded environment. The main difference between this method and traditional ones is that it adopts separated blobs as the input of the people number estimator. The blobs are selected according to their features after background estimation and calibration by tracking. After this, each selected blob in the scene is trained to predict the number of persons in the blob and the people number estimator is formed by combining trained sub-estimators according to a pre-defined rule. / In the last part, I discussed the method to analyze the crowd motion from a different angle: by video energies. I mainly use the defined energies to identify the human crowd density and human abnormal behaviors in the crowd. I define two categories of video energies based on intensity variation and motion features and adopt two surveillance methods for the two energies accordingly. Using wavelet analysis of the energy curves, I obtained a result which shows that both methods can be used to deal with crowd modeling and real-time surveillance satisfactorily. / In this thesis, I address the problem of crowd surveillance and present the methodology of how to model and monitor the crowd. The methodology is mainly based on motion features of crowd under human constrains. By utilizing this methodology, dynamic velocity field is extracted and later used for learning. Thereafter, learning technology based on appropriate features will enable the system to classify the crowd motion and behaviors. In this thesis, I tried four topics in crowd modeling and the contributions are in the following areas, namely, (1) robust people counting in crowded environment, (2) the detection and identification of abnormal behaviors in crowded environment, (3) modeling crowd behaviors via human motion constrains, and (4) modeling crowd behaviors using crowd energy. / Secondly, I introduced a human abnormal behavior identification system in the crowd based on optical flow features. Optical flow calculation is applied to obtain the velocity field of the raw images and the corresponding optical flows in the foreground are selected and processed. Then, the optical flows are encoded by support vector machine to identify the abnormal behaviors of humans in crowded environments. Experimental results show that this method can handle some places where it is very crowded while the traditional methods can not. / The work in this thesis has provided a theoretical framework for crowd modeling research and also proposed corresponding algorithms to understand crowd behaviors. Moreover, it has potential applications in areas such as security monitoring in public regions, and pedestrian fluxes control, etc. / Thirdly, I discussed how crowd modeling using human motion constrains is realized and the quantitative evaluation is given. I declare that the human motion patterns can be added to increase the accuracy and robustness of abnormal behavior identification. In more detail, I applied Bayesian rules to optimize the optical flow calculation result. I also declare that the motion pattern of crowd is similar with that of water when the environment become very crowded and corresponding rules are applied. / Ye, Weizhong. / "May 2008." / Adviser: Yangsheng Xu. / Source: Dissertation Abstracts International, Volume: 70-03, Section: A, page: 0724. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (p. 75-85). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.
2

Topology based global crowd control

Barnett, Adam January 2014 (has links)
We propose a method to determine the flow of large crowds of agents in a scene such that it is filled to its capacity with a coordinated, dynamically moving crowd. Our approach provides a focus on cooperative control across the entire crowd. This is done with a view to providing a method which animators can use to easily populate and fill a scene. We solve this global planning problem by first finding the topology of the scene using a Reeb graph, which is computed from a Harmonic field of the environment. The Maximum flow can then be calculated across this graph detailing how the agents should move through the space. This information is converted back from the topological level to the geometric using a route planner and the Harmonic field. We provide evidence of the system’s effectiveness in creating dynamic motion through comparison to a recent method. We also demonstrate how this system allows the crowd to be controlled globally with a couple of simple intuitive controls and how it can be useful for the purpose of designing buildings and providing control in team sports.
3

Using Global Objectives to Control Behaviors in Crowds

Lee, Domin 14 April 2008 (has links)
No description available.
4

Structuralist and interactionist perspectives of collective behavior and control of crowds.

Gunes, Ismail Dincer 08 1900 (has links)
The purpose of this thesis is to understand the concept of collective behavior from different theoretical perspectives and the policy implications they imply for the Turkish Riot Police Units. The civil disturbances in the 1960s have clearly illustrated range of problems in the domain of crowd control. This work will start with the general characteristics and the classification of collective behavior. Second, two main perspectives on collective behavior, which are the structuralist and the interactionist perspectives, will be examined respectively. The question will be asked whether these two perspectives efficiently and effectively explain the crowds and the crowd control. Finally, the other factors in crowd control will be explored, and recommendations concerning the handling of crowds in a more peaceful manner will be made.
5

Pour une sociologie des rassemblements : construction sociale, imaginaire, action collective et maintien de l'ordre / Towards a sociology of gatherings : social construction, imaginary, collective action and crowd control

Gardenier, Matthijs 19 September 2014 (has links)
Ce travail de thèse entend étudier les rassemblements de personnes. Plutôt que le terme de « foule», trop lié à la psychologie des foules, c‘est le terme de rassemblement, théorisé par Georges Lefebvre qui sera utilisé. Il est défini comme un agrégat intentionnel d‘acteurs sociaux, qui interagissent, communiquent et agissent ensemble.Contrairement aux conclusions de la psychologie des foules, les rassemblements de personnes sont conçus comme un lieu d‘intense construction sociale. Ceux-ci sont des objets sociaux normés. Ils sont le lieu de nombreuses stratégies intentionnelles de la part des acteurs sociaux qui y participent.Dans le cadre de cette étude, ce sont les fins des participants, les mécanismes de mobilisation, leur répertoire d‘action, qui sont au centre de la compréhension de notre objet. Elle passe aussi l‘étude des interactions entre participants, ainsi que des mécanismes de communication qui rendent possible ces interactions. Enfin, ce sont les dynamiques de maintien de l‘ordre et d‘exercice de pouvoir par les participants qui sont au centre de notre attention.Ces problématiques ont été confrontées au terrain par une étude comparative entre manifestations, rassemblements sportifs et rassemblements festifs. Elle a permis de dégager les points communs, mais aussi les différences entre ces évènements. / This dissertation is about crowd gatherings. Rather than the term ―crowd‖, methodologically linked to the psychology of crowds, we will use the term ―gathering‖, theorized by Georges Lefebvre. It is defined as an intentional aggregate of social actors who interact, communicate and act together.Unlike the psychology of crowds, gatherings of people are considered as a place of intense social construction. Those objects are understandable by the social norms that they adopt. They are also a place of numerous intentional strategies put into place by the social actors involved.In this study, the objectives of the participants as well as mechanisms of mobilization and repertories of action, are central to the understanding of our subject . It will also involve the study of interactions between participants as well the communication mechanisms within the gathering. Finally, we will focus on crowd control, law enforcement and the empowerment of the participants.These issues have been confronted to the social field by a comparative case study between demonstrations, sports gatherings and festive gatherings. It identifies the common points but also differences between these events.
6

Bortom melodi och harmoni: det beväpnande ljudet : Om ljud som vapen och sonisk krigsföring

Kronander, Kristoffer January 2018 (has links)
Detta arbete undersöker hur soniska vågor kan användas som vapen. Särskild vikt läggs vid att förstå hur ljudet avtäcktes från att vara en osynlig och hämningslös energi till att bli en fysiskt producerande våldsam kraft under den megafoniska eran och efter. Uppsatsen argumenterar för att soniska vapen måste föregås av avancerad teknologisk utveckling samt ett intresse för att föra ett annat typ av krig, utan dödsfall och skjutvapen. Flera exempel ges som visar att ljudvapen också ofta används för att kontrollera en population. Sonisk krigsföring fastställs till att innefatta användandet av psykologisk, våldsam och fysisk akustisk kraft för att alternera eller påverka psykiska och fysiska aspekter hos en population, kropp eller folkmassa.
7

Made in Mecca: Expertise, Smart Technology, and Hospitality in the Post-Oil Holy City

Shah, Omer January 2021 (has links)
Under the new Vision 2030 national transformation plan, the kingdom of Saudi Arabia seeks to increase number of annual pilgrims from eight million to thirty million. If oil has certain limits, then pilgrimage is framed as lasting “forever.” But this exuberant claim of “forever” belies a more subtle transformation unfolding at the level of knowledge, technology, and hospitality as Mecca and its crowds are made and re-made into a resource for a national economy. This dissertation examines the Saudi state’s efforts to manage, and ultimately intensify and optimize Mecca’s pilgrimage through new sciences and technologies of crowd management, logistics, and secular hospitality. I demonstrate how these new forms of knowledge production operate in tension with older and decidedly more Islamic ways of knowing, managing, and belonging in the holy city. Instead of approaching religious knowledge and secular knowledge as discrete spheres, my research explores their entanglements and aporias across a range of techno-political practices: navigation, hospitality, urban planning, systems thinking, crowd management, and optimization. Ultimately, I explore how in this moment of ritual intensity, the cosmopolitan logics of the holy city come to be blunted.
8

Investigating Communication and Warning Channels to Enhance Crowd Management Strategies: a Study of Hajj Pilgrims in Saudi Arabia

Taibah, Hassan 05 1900 (has links)
The global increase in the number of mass gatherings and crowded events has brought with it new emergencies and unintended consequences for public administrators and first responders. Crowd managers attempt to overcome these challenges by enhancing operations, alleviating financial losses, keeping event organizers safe from liability and, most importantly, keeping the attendees safe. Effective communication among and between officials and guests has been identified as a key element in this process. However, there is a lack of risk communication studies, especially about heterogeneous crowds that congregate at religious events. With this gap in mind, this research aims to investigate the use of major communication channels available and/or preferred by Muslim pilgrims in Makkah, Saudi Arabia during Hajj to gauge their effectiveness in communicating risk information. This annual religious pilgrimage was chosen because it attracts over 2 million pilgrims from more than 140 countries, most of whom speak different languages and belong to different cultures but perform the same rituals at the same time. This dissertation seeks to answer three broad research questions: “what are the most popular communication channels used by pilgrims,” “what are the weaknesses of the current communication strategies,” and “what can be done to improve risk communication among pilgrims, and between pilgrims and authorities to enhance crowd control and crowd management strategies.” The protective action decision model (PADM) is used as the theoretical framework to understand the influence of six factors (environmental cues, social cues, information sources, channel access and preferences, warning messages, and receiver characteristics) on risk communication. In collaboration with the Transportation and Crowd Management Center of Research Excellence (TCMCORE) of Saudi Arabia, a convenience sampling strategy was employed to interview 348 pilgrims in the Prophet’s Mosque area, during the Hajj of 2013. The surveys were conducted in Arabic and English and included pilgrims from different backgrounds and countries. Data analysis included an evaluation of the correlation between the use of risk communication channels and receiver characteristics, message content, and information sources. Findings highlight low percentages in the overall use of communication channels. It also demonstrated an over-dependence on channels that foster the passive top-down communication strategy (such as TV stations, messages at mosques, billboard, text messages, and pamphlets), while marginalizing channels that foster the horizontal and bottom-up strategies (such as bilingual staff outreach and social media). The findings also show the differences in risk communication channels used by pilgrims from different socio-demographic groups. The study concludes that adopting bottom-up and horizontal strategies is key to effective risk communication. Additionally, crowd managers must recognize the importance of social media and use this medium more proactively. They can also work towards increasing the overall effectiveness of risk communication channels by addressing the impact of information sources, channel access, and receiver characteristics to better suit the needs of pilgrims. Finally, the study states the limitations and future research directions.

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