997 resultados para mobile surveillance


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Addressing core issues in mobile surveillance, we present an architecture for querying and retrieving distributed, semi-permanent multi-modal data through challenged networks with limited connectivity. The system provides a rich set of queries for spatio-temporal querying in a surveillance context, and uses the network availability to provide best quality of service. It incrementally and adaptively refines the query, using data already retrieved that exists on static platforms and on-demand data that it requests from mobile platforms. We demonstrate the system using a real surveillance system on a mobile 20 bus transport network coupled with static bus depot infrastructure. In addition, we show the robustness of the system in handling different conditions in the underlying infrastructure by running simulations on a real, but historic dataset collected in an offline manner.

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We present a comparative evaluation of the state-of-art algorithms for detecting pedestrians in low frame rate and low resolution footage acquired by mobile sensors. Four approaches are compared: a) The Histogram of Oriented Gradient (HoG) approach [1]; b) A new histogram feature that is formed by the weighted sum of both the gradient magnitude and the filter responses from a set of elongated Gaussian filters [2] corresponding to the quantised orientation, called Histogram of Oriented Gradient Banks (HoGB) approach; c) The codebook based HoG feature with branch-and-bound (efficient subwindow search) algorithm [3] and; d) The codebook based HoGB approach. Results show that the HoG based detector achieves the highest performance in terms of the true positive detection, the HoGB approach has the lowest false positives whilst maintaining a comparable true positive rate to the HoG, and the codebook approaches allow computationally efficient detection.

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In this paper, we present a system for pedestrian detection involving scenes captured by mobile bus surveillance cameras in busy city streets. Our approach integrates scene localization, foreground and background separation, and pedestrian detection modules into a unified detection framework. The scene localization module performs a two stage clustering of the video data. In the first stage, SIFT Homography is applied to cluster frames in terms of their structural similarities and second stage further clusters these aligned frames in terms of lighting. This produces clusters of images which are differential in viewpoint and lighting. A kernel density estimation (KDE) method for colour and gradient foreground-background separation are then used to construct background model for each image cluster which is subsequently used to detect all foreground pixels. Finally, using a hierarchical template matching approach, pedestrians can be identified. We have tested our system on a set of real bus video datasets and the experimental results verify that our system works well in practice.

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In Australia, the Queensland fruit fly (B. tryoni), is the most destructive insect pest of horticulture, attacking nearly all fruit and vegetable crops. This project has researched and prototyped a system for monitoring fruit flies so that authorities can be alerted when a fly enters a crop in a more efficient manner than is currently used. This paper presents the idea of our sensor platform design as well as the fruit fly detection and recognition algorithm by using machine vision techniques. Our experiments showed that the designed trap and sensor platform is capable to capture quality fly images, the invasive flies can be successfully detected and the average precision of the Queensland fruit fly recognition is 80% from our experiment.

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In this paper we present a real-time foreground–background segmentation algorithm that exploits the following observation (very often satisfied by a static camera positioned high in its environment). If a blob moves on a pixel p that had not changed its colour significantly for a few frames, then p was probably part of the background when its colour was static. With this information we are able to update differentially pixels believed to be background. This work is relevant to autonomous minirobots, as they often navigate in buildings where smart surveillance cameras could communicate wirelessly with them. A by-product of the proposed system is a mask of the image regions which are demonstrably background. Statistically significant tests show that the proposed method has a better precision and recall rates than the state of the art foreground/background segmentation algorithm of the OpenCV computer vision library.

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In many cities around the world, surveillance by a pervasive net of CCTV cameras is a common phenomenon in an attempt to uphold safety and security across the urban environment. Video footage is being recorded and stored, sometimes live feeds are being watched in control rooms hidden from public access and view. In this study, we were inspired by Steve Mann’s original work on sousveillance (surveillance from below) to examine how a network of camera equipped urban screens could allow the residents of Oulu in Finland to collaborate on the safekeeping of their city. An agile, rapid prototyping process led to the design, implementation and ‘in the wild’ deployment of the UbiOpticon screen application. Live video streams captured by web cams integrated at the top of 12 distributed urban screens were broadcast and displayed in a matrix arrangement on all screens. The matrix also included live video streams of two roaming mobile phone cameras. In our field study we explored the reactions of passers-by and users of this screen application that seeks to inverse Bentham’s original panopticon by allowing the watched to be watchers at the same time. In addition to the original goal of participatory sousveillance, the system’s live video feature sparked fun and novel user-led apprlopriations.

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The ability of new information and communication technologies to pierce previously impenetrable physical, personal, and social boundaries has particular relevance to contemporary society and young people as there is now more information that can be collected, accessed, and distributed about individuals and groups. The ability to know about each other has become a central feature of many young people’s lives. The need to know is further complicated by other questions – Who knows? What do they know? What are the implications of this knowledge?. These questions are a consequence of society having become more mobile and networked enabling increased surveillance, tracking, and spreading of dis/information. With the acceleration of new pervasive and immersive technologies, these questions have taken on a new urgency and significance that go beyond an Orwellian Big Brother scenario. This chapter extends Foucault’s notion of the panopticon to take account of the challenges of an AmI environment of smart networked devices. By drawing on examples of recent young adult fiction, I examine some of the ways in which these texts invite their readers to reflect and speculate on the uneasy relationship between surveillance and democracy and what this means for individual rights and freedom, and a sense of place and belonging.

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BACKGROUND Early detection by skin self-examination (SSE) could improve outcomes from melanoma. Mobile teledermoscopy may aid this process. OBJECTIVES To establish clinical accuracy of SSE plus mobile teledermoscopy compared to clinical skin examination (CSE) and test whether providing people with detailed SSE instructions improves accuracy. METHODS Men and women 50-64 years (n=58) performed SSE plus mobile teledermoscopy in their homes between May and November 2013 and were given technical instructions plus detailed SSE instructions (intervention) or technical instructions only (control). Within three months, they underwent a CSE. Outcome measures included: a) body sites examined, lesions photographed, and missed; b) sensitivityof SSE plus mobile teledermoscopy compared to in-person CSE using either patients or lesions as denominator, and; c) concordance of telediagnosis with CSE. RESULTS: 49 of 58 randomised participants completed the study, and submitted 309 lesions to the teledermatologist (156 intervention; 153 control group). Intervention group participants were more likely to submit lesions from their legs compared to control (p=0.03), no other differences between groups in number or site of missed lesions.11 participants (22%) did not photograph 14 pigmented lesions the dermatologist considered worthwhile photographing or requiring clinical monitoring. Sensitivity of SSE plus mobile teledermoscopy was 81.8% (95% confidence interval 64.5-93.0) using the patient as the denominator and 41.9 (27.6-56.2) using the lesion as denominator.-There was substantial agreement between telediagnosis and CSE (Kappa =0.90) accounting for differential diagnoses. CONCLUSIONS SSE plus mobile teledermoscopy is promising for surveillance of particular lesions even without provision of detailed SSE instructions, but in the format tested in this study, consumers may overlook lesions and send many non-pigmented lesions. This investigation demonstrates that high quality dermoscopic images can be taken by patients at home and for those sent, telediagnosis is highly accurate.

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Cities and urban spaces around the world are changing rapidly from their origins in the industrialising world to a post-industrial, hard wired landscape. A further embellishment is the advent of mobile media technologies supported by both existing and new communications and computing technology which claim to put the urban dweller at the heart of a new, informed and ‘liberated’ seat of participatory urban governance. This networked, sensor enabled society permits flows of information in a multitude of directions ostensibly empowering the citizenry through ‘smart’ installations such as ‘talking bus stops’ detailing services, delays, transport interconnections and even weather conditions along desired routes. However, while there is considerable potential for creative and transformative kinds of citizen participation, there is also the momentum for ‘function-creep’, whereby vast amounts of data are garnered in a broad application of urban surveillance. This kind of monitoring and capacity for surveillance connects with attempts by civic authorities to regulate, restrict, rebrand and reframe urban public spaces into governable and predictable arenas of consumption. This article considers questions around the possibilities for retaining and revitalising forms of urban citizenship, set in the context of Marshall’s original premise of civil, social and political citizenship(s) in the middle of the last century, following World War Two and the coming of the modern welfare state.

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Sensor networks represent an attractive tool to observe the physical world. Networks of tiny sensors can be used to detect a fire in a forest, to monitor the level of pollution in a river, or to check on the structural integrity of a bridge. Application-specific deployments of static-sensor networks have been widely investigated. Commonly, these networks involve a centralized data-collection point and no sharing of data outside the organization that owns it. Although this approach can accommodate many application scenarios, it significantly deviates from the pervasive computing vision of ubiquitous sensing where user applications seamlessly access anytime, anywhere data produced by sensors embedded in the surroundings. With the ubiquity and ever-increasing capabilities of mobile devices, urban environments can help give substance to the ubiquitous sensing vision through Urbanets, spontaneously created urban networks. Urbanets consist of mobile multi-sensor devices, such as smart phones and vehicular systems, public sensor networks deployed by municipalities, and individual sensors incorporated in buildings, roads, or daily artifacts. My thesis is that "multi-sensor mobile devices can be successfully programmed to become the underpinning elements of an open, infrastructure-less, distributed sensing platform that can bring sensor data out of their traditional close-loop networks into everyday urban applications". Urbanets can support a variety of services ranging from emergency and surveillance to tourist guidance and entertainment. For instance, cars can be used to provide traffic information services to alert drivers to upcoming traffic jams, and phones to provide shopping recommender services to inform users of special offers at the mall. Urbanets cannot be programmed using traditional distributed computing models, which assume underlying networks with functionally homogeneous nodes, stable configurations, and known delays. Conversely, Urbanets have functionally heterogeneous nodes, volatile configurations, and unknown delays. Instead, solutions developed for sensor networks and mobile ad hoc networks can be leveraged to provide novel architectures that address Urbanet-specific requirements, while providing useful abstractions that hide the network complexity from the programmer. This dissertation presents two middleware architectures that can support mobile sensing applications in Urbanets. Contory offers a declarative programming model that views Urbanets as a distributed sensor database and exposes an SQL-like interface to developers. Context-aware Migratory Services provides a client-server paradigm, where services are capable of migrating to different nodes in the network in order to maintain a continuous and semantically correct interaction with clients. Compared to previous approaches to supporting mobile sensing urban applications, our architectures are entirely distributed and do not assume constant availability of Internet connectivity. In addition, they allow on-demand collection of sensor data with the accuracy and at the frequency required by every application. These architectures have been implemented in Java and tested on smart phones. They have proved successful in supporting several prototype applications and experimental results obtained in ad hoc networks of phones have demonstrated their feasibility with reasonable performance in terms of latency, memory, and energy consumption.

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Much of our understanding and management of ecological processes requires knowledge of the distribution and abundance of species. Reliable abundance or density estimates are essential for managing both threatened and invasive populations, yet are often challenging to obtain. Recent and emerging technological advances, particularly in unmanned aerial vehicles (UAVs), provide exciting opportunities to overcome these challenges in ecological surveillance. UAVs can provide automated, cost-effective surveillance and offer repeat surveys for pest incursions at an invasion front. They can capitalise on manoeuvrability and advanced imagery options to detect species that are cryptic due to behaviour, life-history or inaccessible habitat. UAVs may also cause less disturbance, in magnitude and duration, for sensitive fauna than other survey methods such as transect counting by humans or sniffer dogs. The surveillance approach depends upon the particular ecological context and the objective. For example, animal, plant and microbial target species differ in their movement, spread and observability. Lag-times may exist between a pest species presence at a site and its detectability, prompting a need for repeat surveys. Operationally, however, the frequency and coverage of UAV surveys may be limited by financial and other constraints, leading to errors in estimating species occurrence or density. We use simulation modelling to investigate how movement ecology should influence fine-scale decisions regarding ecological surveillance using UAVs. Movement and dispersal parameter choices allow contrasts between locally mobile but slow-dispersing populations, and species that are locally more static but invasive at the landscape scale. We find that low and slow UAV flights may offer the best monitoring strategy to predict local population densities in transects, but that the consequent reduction in overall area sampled may sacrifice the ability to reliably predict regional population density. Alternative flight plans may perform better, but this is also dependent on movement ecology and the magnitude of relative detection errors for different flight choices. Simulated investigations such as this will become increasingly useful to reveal how spatio-temporal extent and resolution of UAV monitoring should be adjusted to reduce observation errors and thus provide better population estimates, maximising the efficacy and efficiency of unmanned aerial surveys.

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This paper investigates the role that INTERPOL surveillance – the Mobile INTERPOL Network Database (MIND) and the Fixed INTERPOL Network Database (FIND) – played in the War on Terror since its inception in 2005. MIND/FIND surveillance allows countries to screen people and documents systematically at border crossings against INTERPOL databases on terrorists, fugitives, and stolen and lost travel documents. Such documents have been used in the past by terrorists to transit borders. By applying methods developed in the treatment-effects literature, this paper establishes that countries adopting MIND/FIND experienced fewer transnational terrorist attacks than had they not adopted MIND/FIND. Our estimates indicate that, on average, during 2008–2011, adopting and using MIND/FIND results in 1.23 fewer transnational terrorist incidents each year per 100 million people. Thus, a country like France with a population just above 64 million people in 2008 would have 0.79 fewer transnational terrorist incidents per year owing to its use of INTERPOL surveillance. For most treatment countries, this amounts to a sizeable proportional reduction of about 60 per cent.

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This paper examines the use of visual technologies by political activists in protest situations to monitor police conduct. Using interview data with Australian video activists, this paper seeks to understand the motivations, techniques and outcomes of video activism, and its relationship to counter-surveillance and police accountability. Our data also indicated that there have been significant transformations in the organization and deployment of counter-surveillance methods since 2000, when there were large-scale protests against the World Economic Forum meeting in Melbourne accompanied by a coordinated campaign that sought to document police misconduct. The paper identifies and examines two inter-related aspects of this: the act of filming and the process of dissemination of this footage. It is noted that technological changes over the last decade have led to a proliferation of visual recording technologies, particularly mobile phone cameras, which have stimulated a corresponding proliferation of images. Analogous innovations in internet communications have stimulated a coterminous proliferation of potential outlets for images Video footage provides activists with a valuable tool for safety and publicity. Nevertheless, we argue, video activism can have unintended consequences, including exposure to legal risks and the amplification of official surveillance. Activists are also often unable to control the political effects of their footage or the purposes to which it is used. We conclude by assessing the impact that transformations in both protest organization and media technologies might have for counter-surveillance techniques based on visual surveillance.