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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.
201

Automating Deep-Sea Video Annotation

Egbert, Hanson 01 June 2021 (has links) (PDF)
As the world explores opportunities to develop offshore renewable energy capacity, there will be a growing need for pre-construction biological surveys and post-construction monitoring in the challenging marine environment. Underwater video is a powerful tool to facilitate such surveys, but the interpretation of the imagery is costly and time-consuming. Emerging technologies have improved automated analysis of underwater video, but these technologies are not yet accurate or accessible enough for widespread adoption in the scientific community or industries that might benefit from these tools. To address these challenges, prior research developed a website that allows to: (1) Quickly play and annotate underwater videos, (2) Create a short tracking video for each annotation that shows how an annotated concept moves in time, (3) Verify the accuracy of existing annotations and tracking videos, (4) Create a neural network model from existing annotations, and (5) Automatically annotate unwatched videos using a model that was previously created. It uses both validated and unvalidated annotations and automatically generated annotations from trackings to count the number of Rathbunaster californicus (starfish) and Strongylocentrotus fragilis (sea urchin) with count accuracy of 97% and 99%, respectively, and F1 score accuracy of 0.90 and 0.81, respectively. The thesis explores several improvements to the model above. First, a method to sync JavaScript video frames to a stable Python environment. Second, reinforcement training using marine biology experts and the verification feature. Finally, a hierarchical method that allows the model to combine predictions of related concepts. On average, this method improved the F1 scores from 0.42 to 0.45 (a relative increase of 7%) and count accuracy from 58% to 69% (a relative increase of 19%) for the concepts Umbellula Lindahli and Funiculina.
202

Exploring the Time Course of Object Persistence in Apparent Motion: Studies with the Simple Apparent Motion Display and the Ternus Display

Jaffee, Samuel D. 23 July 2015 (has links)
No description available.
203

Scene-Dependent Human Intention Recognition for an Assistive Robotic System

Duncan, Kester 17 January 2014 (has links)
In order for assistive robots to collaborate effectively with humans for completing everyday tasks, they must be endowed with the ability to effectively perceive scenes and more importantly, recognize human intentions. As a result, we present in this dissertation a novel scene-dependent human-robot collaborative system capable of recognizing and learning human intentions based on scene objects, the actions that can be performed on them, and human interaction history. The aim of this system is to reduce the amount of human interactions necessary for communicating tasks to a robot. Accordingly, the system is partitioned into scene understanding and intention recognition modules. For scene understanding, the system is responsible for segmenting objects from captured RGB-D data, determining their positions and orientations in space, and acquiring their category labels. This information is fed into our intention recognition component where the most likely object and action pair that the user desires is determined. Our contributions to the state of the art are manifold. We propose an intention recognition framework that is appropriate for persons with limited physical capabilities, whereby we do not observe human physical actions for inferring intentions as is commonplace, but rather we only observe the scene. At the core of this framework is our novel probabilistic graphical model formulation entitled Object-Action Intention Networks. These networks are undirected graphical models where the nodes are comprised of object, action, and object feature variables, and the links between them indicate some form of direct probabilistic interaction. This setup, in tandem with a recursive Bayesian learning paradigm, enables our system to adapt to a user's preferences. We also propose an algorithm for the rapid estimation of position and orientation values of scene objects from single-view 3D point cloud data using a multi-scale superquadric fitting approach. Additionally, we leverage recent advances in computer vision for an RGB-D object categorization procedure that balances discrimination and generalization as well as a depth segmentation procedure that acquires candidate objects from tabletops. We demonstrate the feasibility of the collaborative system presented herein by conducting evaluations on multiple scenes comprised of objects from 11 categories, along with 7 possible actions, and 36 possible intentions. We achieve approximately 81% reduction in interactions overall after learning despite changes to scene structure.
204

Region-based face detection, segmentation and tracking. framework definition and application to other objects

Vilaplana Besler, Verónica 17 December 2010 (has links)
One of the central problems in computer vision is the automatic recognition of object classes. In particular, the detection of the class of human faces is a problem that generates special interest due to the large number of applications that require face detection as a first step. In this thesis we approach the problem of face detection as a joint detection and segmentation problem, in order to precisely localize faces with pixel accurate masks. Even though this is our primary goal, in finding a solution we have tried to create a general framework as independent as possible of the type of object being searched. For that purpose, the technique relies on a hierarchical region-based image model, the Binary Partition Tree, where objects are obtained by the union of regions in an image partition. In this work, this model is optimized for the face detection and segmentation tasks. Different merging and stopping criteria are proposed and compared through a large set of experiments. In the proposed system the intra-class variability of faces is managed within a learning framework. The face class is characterized using a set of descriptors measured on the tree nodes, and a set of one-class classifiers. The system is formed by two strong classifiers. First, a cascade of binary classifiers simplifies the search space, and afterwards, an ensemble of more complex classifiers performs the final classification of the tree nodes. The system is extensively tested on different face data sets, producing accurate segmentations and proving to be quite robust to variations in scale, position, orientation, lighting conditions and background complexity. We show that the technique proposed for faces can be easily adapted to detect other object classes. Since the construction of the image model does not depend on any object class, different objects can be detected and segmented using the appropriate object model on the same image model. New object models can be easily built by selecting and training a suitable set of descriptors and classifiers. Finally, a tracking mechanism is proposed. It combines the efficiency of the mean-shift algorithm with the use of regions to track and segment faces through a video sequence, where both the face and the camera may move. The method is extended to deal with other deformable objects, using a region-based graph-cut method for the final object segmentation at each frame. Experiments show that both mean-shift based trackers produce accurate segmentations even in difficult scenarios such as those with similar object and background colors and fast camera and object movements. Lloc i / Un dels problemes més importants en l'àrea de visió artificial és el reconeixement automàtic de classes d'objectes. En particular, la detecció de la classe de cares humanes és un problema que genera especial interès degut al gran nombre d'aplicacions que requereixen com a primer pas detectar les cares a l'escena. A aquesta tesis s'analitza el problema de detecció de cares com un problema conjunt de detecció i segmentació, per tal de localitzar de manera precisa les cares a l'escena amb màscares que arribin a precisions d'un píxel. Malgrat l'objectiu principal de la tesi és aquest, en el procés de trobar una solució s'ha intentat crear un marc de treball general i tan independent com fos possible del tipus d'objecte que s'està buscant. Amb aquest propòsit, la tècnica proposada fa ús d'un model jeràrquic d'imatge basat en regions, l'arbre binari de particions (BPT: Binary Partition Tree), en el qual els objectes s'obtenen com a unió de regions que provenen d'una partició de la imatge. En aquest treball, s'ha optimitzat el model per a les tasques de detecció i segmentació de cares. Per això, es proposen diferents criteris de fusió i de parada, els quals es comparen en un conjunt ampli d'experiments. En el sistema proposat, la variabilitat dins de la classe cara s'estudia dins d'un marc de treball d'aprenentatge automàtic. La classe cara es caracteritza fent servir un conjunt de descriptors, que es mesuren en els nodes de l'arbre, així com un conjunt de classificadors d'una única classe. El sistema està format per dos classificadors forts. Primer s'utilitza una cascada de classificadors binaris que realitzen una simplificació de l'espai de cerca i, posteriorment, s'aplica un conjunt de classificadors més complexes que produeixen la classificació final dels nodes de l'arbre. El sistema es testeja de manera exhaustiva sobre diferents bases de dades de cares, sobre les quals s'obtenen segmentacions precises provant així la robustesa del sistema en front a variacions d'escala, posició, orientació, condicions d'il·luminació i complexitat del fons de l'escena. A aquesta tesi es mostra també que la tècnica proposada per cares pot ser fàcilment adaptable a la detecció i segmentació d'altres classes d'objectes. Donat que la construcció del model d'imatge no depèn de la classe d'objecte que es pretén buscar, es pot detectar i segmentar diferents classes d'objectes fent servir, sobre el mateix model d'imatge, el model d'objecte apropiat. Nous models d'objecte poden ser fàcilment construïts mitjançant la selecció i l'entrenament d'un conjunt adient de descriptors i classificadors. Finalment, es proposa un mecanisme de seguiment. Aquest mecanisme combina l'eficiència de l'algorisme mean-shift amb l'ús de regions per fer el seguiment i segmentar les cares al llarg d'una seqüència de vídeo a la qual tant la càmera com la cara es poden moure. Aquest mètode s'estén al cas de seguiment d'altres objectes deformables, utilitzant una versió basada en regions de la tècnica de graph-cut per obtenir la segmentació final de l'objecte a cada imatge. Els experiments realitzats mostren que les dues versions del sistema de seguiment basat en l'algorisme mean-shift produeixen segmentacions acurades, fins i tot en entorns complicats com ara quan l'objecte i el fons de l'escena presenten colors similars o quan es produeix un moviment ràpid, ja sigui de la càmera o de l'objecte.
205

Moving Object Identification And Event Recognition In Video Surveillamce Systems

Orten, Burkay Birant 01 August 2005 (has links) (PDF)
This thesis is devoted to the problems of defining and developing the basic building blocks of an automated surveillance system. As its initial step, a background-modeling algorithm is described for segmenting moving objects from the background, which is capable of adapting to dynamic scene conditions, as well as determining shadows of the moving objects. After obtaining binary silhouettes for targets, object association between consecutive frames is achieved by a hypothesis-based tracking method. Both of these tasks provide basic information for higher-level processing, such as activity analysis and object identification. In order to recognize the nature of an event occurring in a scene, hidden Markov models (HMM) are utilized. For this aim, object trajectories, which are obtained through a successful track, are written as a sequence of flow vectors that capture the details of instantaneous velocity and location information. HMMs are trained with sequences obtained from usual motion patterns and abnormality is detected by measuring the distance to these models. Finally, MPEG-7 visual descriptors are utilized in a regional manner for object identification. Color structure and homogeneous texture parameters of the independently moving objects are extracted and classifiers, such as Support Vector Machine (SVM) and Bayesian plug-in (Mahalanobis distance), are utilized to test the performance of the proposed person identification mechanism. The simulation results with all the above building blocks give promising results, indicating the possibility of constructing a fully automated surveillance system for the future.
206

The audiovisual object

Connor, Andrew John Caldwell January 2017 (has links)
The ʻaudiovisual objectʼ is a fusion of sound object and visual object to create an identifiable perceptual phenomenon, which can be treated as a ʻbuilding blockʼ in the creation of audiovisual work based primarily on electroacoustic composition practice and techniques. This thesis explores how the audiovisual object can be defined and identified in existing works, and offers an examination of how it can be used as a compositional tool. The historical development of the form and the effect of the performance venue on audience immersion is also explored. The audiovisual object concept builds upon theories of electroacoustic composition and film sound design. The audiovisual object is defined in relation to existing concepts of the sound object and visual object, while synaesthesia and cross-modal perception are examined to show how the relationship between sound and vision in the audiovisual object can be strengthened. Electroacoustic composition and animation both developed through technological advances, either the manipulation of recorded sounds, or the manipulation of drawn/photographed objects. The key stages in development of techniques and theories in both disciplines are examined and compared against each other, highlighting correlations and contrasts. The physical space where the audiovisual composition is performed also has a bearing on how the work is perceived and received. Current standard performance spaces include acousmatic concert systems, which emphasize the audio aspect over the visual, and the cinema, which focuses on the visual. Spaces which afford a much higher level of envelopment in the work include hemispheric projection, while individual experience through virtual reality systems could become a key platform. The key elements of the audiovisual object, interaction between objects and their successful use in audiovisual compositions are also investigated in a series of case studies. Specific audiovisual works are examined to highlight techniques to create successful audiovisual objects and interactions. As this research degree is in creative practice, a portfolio of 4 composed works is also included, with production notes explaining the inspiration behind and symbolism within each work, along with the practical techniques employed in their creation. The basis for each work is a short electroacoustic composition which has then been developed with abstract 3D CGI animation into an audiovisual composition, demonstrating the development of my own practice as well as exploring the concept of the audiovisual object. The concept of the audiovisual object draws together existing theories concerning the sound object, visual perception, and phenomenology. The concept, the associated investigation of how audiovisual compositions have evolved over time, and the analysis and critique of case studies based on this central concept contribute both theory and creative practice principles to this form of artistic creativity. This thesis forms a basis for approaching the creative process both as a creator and critic, and opens up a research pathway for further investigation.
207

Object Segmentation, Tracking And Skeletonization In MPEG Video

Padmashree, P 07 1900 (has links) (PDF)
No description available.
208

A temporal message ordering and object tracking application

Lakshman, Kaveti January 1900 (has links)
Master of Science / Department of Computing and Information Sciences / Gurdip Singh / TinyOS is an operating system designed for wireless embedded sensor network which supports the component based development language called Nesc. Wireless sensor network are becoming increasingly popular and are being used in various applications including surveillance applications related to object tracking. Wireless sensor devices called motes can generate an event in the network whenever there is some object moving in its vicinity. This project aims to develop an application which detects the path information of object moving in the sensor field by capturing the order of events occurs in the network. This application builds a logical topology called DAG (Directed acyclic graph) between the motes in the network which is similar to the tree topology where a child can have multiple parents which are in communication range and a level closer to the root. Using a DAG, motes can communicate efficiently to order the events occurring in the sensor field. The root of the DAG is the base station which receives all the events occurred in the network and orders them based on the information it has from previous events received. Every event occurring in the network is assigned a time stamp and is identified by a tuple (mote_id, timestamp) which describes that the mote with identity id has detected the object with the timestamp, and ordering all such events based on the timestamps we get the path information. There are two time stamping algorithms written in this project. In the first time stamping algorithm, whenever any event occurs, it updates the timestamp information of the entire neighboring mote in the field and when the object enters in the detection range of neighboring mote of previous detected mote, it assigns the new timestamp. The second time stamping algorithm just send the message to the parent and it passes on to its parent until the message is received at the base station, and base station itself assigns the timestamps based the event on first come first serve basis. The application is tested by displaying the path information received and ordered at the base station.
209

Object oriented database management systems

Nassis, Antonios 11 1900 (has links)
Modern data intensive applications, such as multimedia systems require the ability to store and manipulate complex data. The classical Database Management Systems (DBMS), such as relational databases, cannot support these types of applications efficiently. This dissertation presents the salient features of Object Database Management Systems (ODBMS) and Persistent Programming Languages (PPL), which have been developed to address the data management needs of these difficult applications. An 'impedance mismatch' problem occurs in the traditional DBMS because the data and computational aspects of the application are implemented using two different systems, that of query and programming language. PPL's provide facilities to cater for both persistent and transient data within the same language, hence avoiding the impedance mismatch problem. This dissertation presents a method of implementing a PPL by extending the language C++ with pre-compiled classes. The classes are first developed and then used to implement object persistence in two simple applications. / Computing / M. Sc. (Information Systems)
210

A GUI BASED SYSTEM FOR AUTOMATIC CONSTRUCTION OF ENGINEERING MODEL SOFTWARE FOR COMMAND RESPONSE AND TELEMETRY GENERATION

Parlanti, Joe, Pinkerton, Ronnie 11 1900 (has links)
International Telemetering Conference Proceedings / November 04-07, 1991 / Riviera Hotel and Convention Center, Las Vegas, Nevada / There exists today, numerous off-the-shelf hardware solutions for the generation of simulated telemetry data streams. The ability to rapidly develop engineering models to drive the data contents of the telemetry is restricted by the lack of contemporary CASE tools. This paper presents an object-oriented Graphical User Interface (GUI) approach to generation of mathematical models in order to reduce the time required for model generation to a fraction of today’s development time, eliminate the need to write substantial amounts of software, and allow reuse of model objects in a manner consistent with the GUI cut, paste, and copy metaphors.

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