• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 38
  • 13
  • 6
  • 5
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 91
  • 91
  • 30
  • 19
  • 19
  • 17
  • 14
  • 13
  • 12
  • 12
  • 12
  • 11
  • 10
  • 10
  • 9
  • 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.
71

Diseño de un sistema de videovigilancia IP para la Autoridad Nacional del Servicio Civil

Perlacios Gastelú, Antonio, Rivera Cardenas, Juan Ramón January 2015 (has links)
El objetivo de la presente tesina es el estudio técnico para la Autoridad del Servicio Civil - Lima, orientado a diseñar un sistema de Videovigilancia IP, lo cual es una tecnología de vigilancia visual con las ventajas digitales de las redes de comunicación IP (Internet Protocol), lo cual permite la supervisión local y/o remota de imágenes y audio así como el tratamiento digital de las imágenes. Existe una gama muy amplia de cámaras con diferentes funcionalidades para satisfacer todas las necesidades y presupuestos. El objetivo es diseñar un sistema de Videovigilancia IP, el cual permita vigilar y controlar a todo el personal para así poder disminuir las pérdidas de los activos. 1. Diseñar un sistema de Videovigilancia IP para una supervisión continua de los datos enviados por la cámara IP. 2. Diseñar la red lógica y física de la Videovigilancia IP. 3. Propuesta de un plan de capacitación de personal involucrado en el manejo de los equipos de Videovigilancia IP, alcanzados en este trabajo. The aim of this thesis is the technical study for the Civil Service Authority - Lima, guied at designing an IP video-surveillance system, which is a visual surveillance technology with digital advantages of IP communication networks (Internet Protocol), allowing the local supervision and/or remote images and audio; and the digital image processing. There is a wide range of cameras with different features to satisfy all needs and budgets. The goal is to design an IP video-surveillance system, which allows monitoring and controlling all personnel in order to reduce losses of assets. 1. Design an IP video-surveillance system for continuous monitoring of the data sent by the IP camera. 2. Design the logical and physical network of video-surveillance IP. 3. Proposal of a training plan for staff involved in the management of IP video-surveillance equipment, made in this work.
72

Securização urbana: da psicoesfera do medo à tecnoesfera da segurança / Securitizing the urban: from psycho-sphere of fear to techno-sphere of security

Lucas de Melo Melgaço 06 December 2010 (has links)
A violência urbana e o medo globalizado, marcas do atual período técnico-científico e informacional, têm alterado as paisagens de diversas partes do mundo através do processo denominado neste trabalho pelo termo securização urbana. Como resposta à sensação de insegurança e de imprevisibilidade, busca-se uma racionalização do território a partir da informatização do cotidiano e da criação de espaços exclusivos. Empiricamente, a securização se traduz em formas arquitetônicas variadas, tendo sido destacadas nesta tese as câmeras de vigilância, os condomínios fechados e as arquiteturas anti-indesejáveis. Transformações espaciais como essas são particularmente intensas em Campinas-SP, município brasileiro ao mesmo tempo muito rico, com importantes empresas e universidades, e muito pobre e violento, portando índices de criminalidade acima da média nacional. Exemplos desse e também de outros lugares do Brasil e da Europa foram analisados em trabalhos de campo que contaram com entrevistas colhidas de agentes locais, fotografias e cartografias, com o intuito de caracterizar o processo de securização e, especialmente, conduzir a uma reflexão sobre suas conseqüências. Conclui-se que a maneira pela qual a segurança tem sido buscada aumenta as desigualdades espaciais e promove uma privatização dos espaços públicos. Além disso, o excesso de vigilância tem reforçado a psicoesfera do medo, tolhido muitas das liberdades individuais e criado novas neuroses e violências. A racionalização do espaço para fins de segurança cria, contudo, as condições para o surgimento de contra-racionalidades, o que reafirma o caráter complexo e dialético do espaço geográfico e aponta para a possibilidade de um futuro marcado pelas solidariedades geográficas e pelo poder revolucionário dos agentes não-hegemônicos. / Urban violence and globalized fear, hallmarks of the current technical-scientific and informational period, have transformed the landscape of different cities of the world through a process called urban securitization\". In response to the feeling of insecurity and unpredictability, territories are being rationalised through the digitalization of everyday life and creation of exclusive areas. Empirically, securitization can be materialized through different architectural forms. This thesis highlights surveillance cameras, gated communities and anti-beggars architectures. These transformations are particularly intense in Campinas, a very wealthy Brazilian city, with important companies and universities, and at the same time very poor and violent, with crime rates above the national average. Examples from this city, but also from other parts of Brazil and Europe, were analyzed in field works which involved interviews with local agents, photos and maps, in order to describe the process of securitization and, especially, to lead to a reflection of their consequences. In conclusion, it can be stated that the way security is being searched increases spatial inequalities and promotes a privatization of public spaces. Furthermore, an excessive surveillance has enhanced the psycho-sphere of fear, has restraint individual liberties and has produced new neuroses and violence. However, rationalisation of space for security purposes facilitates the emergence of counter-rationalities, emphasizing the complex and dialectic qualities of geographic space and indicating the possibility of a future characterized by geographic solidarities and by revolutionary power of non-hegemonic agents.
73

Multiview Face Detection And Free Form Face Recognition For Surveillance

Anoop, K R 05 1900 (has links) (PDF)
The problem of face detection and recognition within a given database has become one of the important problems in computer vision. A simple approach for Face Detection in video is to run a learning based face detector every frame. But such an approach is computationally expensive and completely ignores the temporal continuity present in videos. Moreover the search space can be reduced by utilizing visual cues extracted based on the relevant task at hand(top down approach). Once detection is done next step is to perform a face recognition based on the available database. But the faces detected from face detect or output is neither aligned nor well cropped and is prone to scale change. We call such faces as free form faces. But the current existing algorithms on face recognition assume faces to be properly aligned and cropped, and having the same scale as the faces in the database, which is highly constrained. In this thesis, we propose an integrated detect-track framework for Multiview face detection in videos. We overcome the limitations of the frame based approaches, by utilizing the temporal continuity present in videos and also incorporating the top down information of the task. We model the problem based on the concept from Experiential sampling [2]. This consists of determining certain key positions which are relevant to the task(face detection). These key positions are referred to as attention samples and Multiview face detection is performed only at these locations. These statistical samples are estimated based on the visual cues, past experience and the temporal continuity and is modeled as a Bayesian filtering problem, which is solved using Particle Filters. In order to detect all views we use a tracker integrated with the detector and come out with a novel track termination algorithm using the concepts from Track Before Detect(TBD)[26]. Such an approach is computationally efficient and also results in lower false positive rate. We provide experiments showing the efficiency of the integrated detect-track approach over the multiview face detector approach without a tracker. For free form face recognition we propose to use the concept of Principal Geodesic Analysis(PGA) of the Covariance descriptors obtained from Gabor filters. This is similar to Principal Component Analysis in Euclidean spaces (Covariance descriptors lie on a Riemannian manifold). Such a descriptor is robust to alignment and scaling problems and also are of lower dimensions. We also employ sparse modeling technique for Face recognition task using these Covariance descriptor which are dimensionally reduced by transforming them on to a tangent space, which we call PGA feature. Further, we improve upon the recognition results of linear sparse modeling, by non-linear mapping of the PGA features by employing “Kernel Trick” for these sparse models. We show that the Kernelized sparse models using the PGA features are indeed very efficient for free form face recognition by testing on two standard databases namely AR and YaleB database.
74

Sumarizace obsahu videí / Video Content Summarization

Jaška, Roman January 2018 (has links)
The amount surveillance footage recorded each day is too large for human operators to analyze. A video summary system to process and refine this video data would prove beneficial in many instances. This work defines the problem in terms of its inputs, outputs and sub-problems, identifies suitable techniques and existing works as well as describes a design of such system. The system is implemented, and the results are examined.
75

Sledování osob ve videu z dronu / Tracking People in Video Captured from a Drone

Lukáč, Jakub January 2021 (has links)
Práca rieši možnosť zaznamenávať pozíciu osôb v zázname z kamery drona a určovať ich polohu. Absolútna pozícia sledovanej osoby je odvodená vzhľadom k pozícii kamery, teda vzhľadom k umiestneniu drona vybaveného príslušnými senzormi. Zistené dáta sú po ich spracovaní vykreslené ako príslušné cesty v grafe. Práca si ďalej dáva za cieľ využiť dostupné riešenia čiastkových problémov: detekcia osôb v obraze, identifikácia jednotlivých osôb v čase, určenie vzdialenosti objektu od kamery, spracovanie potrebných senzorových dát. Následne využiť preskúmané metódy a navrhnúť riešenie, ktoré bude v reálnom čase pracovať na uvedenom probléme. Implementačná časť spočíva vo využití akcelerátoru Intel NCS v spojení s Raspberry Pi priamo ako súčasť drona. Výsledný systém je schopný generovať výstup o polohe detekovaných osôb v zábere kamery a príslušne ho prezentovať.
76

Das Verlangen nach Überwachen und Strafen in der Leipziger Bevölkerung

Klimt, Oliver, Müller, Matthias, Rauhut, Heiko January 2004 (has links)
Die vorliegende Arbeit basiert auf der Sekundäranalyse eines Datensatzes, welcher im Stadtgebiet Leipzig im Rahmen eines Forschungspraktikums erhoben wurde. Die Autoren folgen modernen sozialwissenschaftlichen Standards, indem sie theoretisch abgeleitete Hypothesen empirisch prüfen. Besonders hervorhebenswert ist dabei, dass sie ein komplexes Mehrebenenmodell zur Erklärung von Einstellungen zum Überwachen und Strafen theoretisch versiert entwickeln. Beides, Überwachen und Strafen, sind hochbrisante aktuelle Themen in der öffentlichen Diskussion. Gerade in diesen sensiblen Sicherheitsbereichen erweist sich die Bevölkerungsmeinung als ausgesprochen instabil. Immer wieder gelingt es über Mediendramaturgien beachtliche Teile der öffentlichen Meinung für die populistische Konstruktion der Erhöhung der Strafhärte zu mobilisieren. Beeinflussungen der Kriminalitätsfurcht erweisen sich dabei als besonders effektiv. Über die affektive Komponente gelingt es nicht selten auch die kognitive, die Urteilsbildung zu beeinflussen. Hinsichtlich der Einstellungen zum Überwachen ist die Situation ebenfalls nicht besser. Zumindest kurzfristig haben demoskopische Untersuchungen gezeigt, dass ein gewisser Teil der Bevölkerung bereit ist, demokratische Rechte zur Erhöhung der öffentlichen Sicherheit wenn nicht aufzugeben so doch zumindest merklich einschränken zu lassen.:Einleitung/Fragestellung der Untersuchung; Theorien zum Einstellungskonzept, Theoretischer und empirischer Forschungsstand, Auswertung der Leipziger Kriminalitätsstudie, Zusammenfassung und Schlußbetrachtung
77

Recursive-RANSAC: A Novel Algorithm for Tracking Multiple Targets in Clutter

Niedfeldt, Peter C. 02 July 2014 (has links) (PDF)
Multiple target tracking (MTT) is the process of identifying the number of targets present in a surveillance region and the state estimates, or track, of each target. MTT remains a challenging problem due to the NP-hard data association step, where unlabeled measurements are identified as either a measurement of an existing target, a new target, or a spurious measurement called clutter. Existing techniques suffer from at least one of the following drawbacks: divergence in clutter, underlying assumptions on the number of targets, high computational complexity, time-consuming implementation, poor performance at low detection rates, and/or poor track continuity. Our goal is to develop an efficient MTT algorithm that is simple yet effective and that maintains track continuity enabling persistent tracking of an unknown number of targets. A related field to tracking is regression analysis, where the parameters of static signals are estimated from a batch or a sequence of data. The random sample consensus (RANSAC) algorithm was developed to mitigate the effects of spurious measurements, and has since found wide application within the computer vision community due to its robustness and efficiency. The main concept of RANSAC is to form numerous simple hypotheses from a batch of data and identify the hypothesis with the most supporting measurements. Unfortunately, RANSAC is not designed to track multiple targets using sequential measurements.To this end, we have developed the recursive-RANSAC (R-RANSAC) algorithm, which tracks multiple signals in clutter without requiring prior knowledge of the number of existing signals. The basic premise of the R-RANSAC algorithm is to store a set of RANSAC hypotheses between time steps. New measurements are used to either update existing hypotheses or generate new hypotheses using RANSAC. Storing multiple hypotheses enables R-RANSAC to track multiple targets. Good tracks are identified when a sufficient number of measurements support a hypothesis track. The complexity of R-RANSAC is shown to be squared in the number of measurements and stored tracks, and under moderate assumptions R-RANSAC converges in mean to the true states. We apply R-RANSAC to a variety of simulation, camera, and radar tracking examples.
78

An investigation of the economic viability and ethical ramifications of video surveillance in the ICU

Bagge, Laura 01 August 2013 (has links)
The purpose of this review of literature is to investigate the various roles of video surveillance (VS) in the hospital's intensive care unit (ICU) as well as its legal and ethical implications. Today, hospitals spend more money on the ICU than on any other unit. By 2030, the population of those 65 and over is expected to double. 80% of older adults have at least one chronic diseases (Centers for Disease Control and Prevention, 2013). As a consequence, the demand for ICU services will likely increase, which may burden hospital with additional costs. Because of increasing economic pressures, more hospitals are using video surveillance to enhance quality care and reduce ICU costs (Goran, 2012). Research shows that VS enhances positive outcomes among patients and best practice compliance among hospital staff. The results are fewer reports of patient complications and days spent in the ICU, and an increase in reported hospital savings. In addition, VS is becoming an important tool for the families of newborns in the neonatal ICU (NICU). The belief is that the VS can facilitate parent-baby bonding. In the United States of America, privacy rights impose legal restrictions on VS. These rights come from the U.S. Constitution, Statutory law, Regulatory law, and State law. HIPPA authorizes the patient to control the use and disclosure of his or her health information. Accordingly, hospitals are under obligation to inform patients on their right to protected health information. It is appropriate that hospitals use VS for diagnostic purposes as long as they have obtained patient consent. According to modern day privacy experts Charles Fried and Alan Westin, a violation of a person's privacy equates a violation on their liberty and morality. However, if a physician suspects that a third party person is causing harm to the patient, than the use of covert VS is justifiable.
79

The acquisition of coarse gaze estimates in visual surveillance

Benfold, Ben January 2011 (has links)
This thesis describes the development of methods for automatically obtaining coarse gaze direction estimates for pedestrians in surveillance video. Gaze direction estimates are beneficial in the context of surveillance as an indicator of an individual's intentions and their interest in their surroundings and other people. The overall task is broken down into two problems. The first is that of tracking large numbers of pedestrians in low resolution video, which is required to identify the head regions within video frames. The second problem is to process the extracted head regions and estimate the direction in which the person is facing as a coarse estimate of their gaze direction. The first approach for head tracking combines image measurements from HOG head detections and KLT corner tracking using a Kalman filter, and can track the heads of many pedestrians simultaneously to output head regions with pixel-level accuracy. The second approach uses Markov-Chain Monte-Carlo Data Association (MCMCDA) within a temporal sliding window to provide similarly accurate head regions, but with improved speed and robustness. The improved system accurately tracks the heads of twenty pedestrians in 1920x1080 video in real-time and can track through total occlusions for short time periods. The approaches for gaze direction estimation all make use of randomised decision tree classifiers. The first develops classifiers for low resolution head images that are invariant to hair and skin colours using branch decisions based on abstract labels rather than direct image measurements. The second approach addresses higher resolution images using HOG descriptors and novel Colour Triplet Comparison (CTC) based branches. The final approach infers custom appearance models for individual scenes using weakly supervised learning over large datasets of approximately 500,000 images. A Conditional Random Field (CRF) models interactions between appearance information and walking directions to estimate gaze directions for head image sequences.
80

Postures et mutations du plan-séquence fixe, du cinéma des premiers temps à YouTube

Séguin-Tétreault, Mathieu 06 1900 (has links)
Pour respecter les droits d'auteur, la version électronique de ce mémoire a été dépouillée de ses documents visuels. La version intégrale du mémoire a été déposée au Service de la gestion des documents et des archives de l'Université de Montréal. / Privilégiant une approche généalogique et intertextuelle, cette étude interroge le dispositif du plan-séquence fixe à travers ses moments phares dans l’histoire du cinéma et démontre que son usage vise autant à renouer avec le cinéma des premiers temps qu’à poursuivre les préoccupations des cinéastes expérimentaux. Chez Andy Warhol, le plan-séquence fixe s’inscrit dans un rapport de redécouverte et d’enchantement du cinéma des premiers temps. Avec Jeanne Dielman, Chantal Akerman prolonge les traits du modernisme bazinien et de l’avant-garde new-yorkaise. Avec l’avènement de la vidéosurveillance, il se transforme en une esthétique carcérale qui pose dès lors des problèmes éthiques et esthétiques (voyeurisme, degré zéro de la mise en scène, etc.), questionnés dans les documentaires News from Home et Délits flagrants. Forme commune et majeure dans le cinéma d’auteur contemporain de même que dans la culture populaire et amateur (web film, série télé, etc.), le plan-séquence fixe permet d’analyser un ensemble de pratiques et de réalités du cinéma, de l’usine Lumière à YouTube. / Favouring an approach at once genealogical and intertextual, this study explores the practice of the "static sequence shot" (plan-séquence caméra fixe) in cinema. It offers an overview of its significant moments in film history. It tries to show how its use since the 70's can be seen as a reappraisal of early cinema technique, and can also find strong echos in the works of experimental filmmakers, in particular structural filmmaking. For Andy Warhol, the static sequence shot was both a rediscovery and an enchantment of early cinema. In Jeanne Dielman Chantal Akerman's static shots extended Bazinian Modernism into the New York Avant-garde. Since the 80's, with the advent of video surveillance, the static sequence shot becomes associated with a carceral apparatus, posing ethical and aesthetic issues (voyeurism, degree zero mechanisms, etc.). These issues are at the core of the documentary films News from Home and Délits flagrants. Today, we can witness that the static sequence shot has become increasingly important and almost dominant in certain branches of auteur cinema as well as in contemporary popular media culture (web films, T.V. series, etc.) This master's thesis thus claims it allows us to analyse current as well as early practices of cinema, from the Lumière' s factory to YouTube.

Page generated in 0.0766 seconds