A testing framework was developed to address system spatial and temporal performance characteristics in a two-dimensional (2D) human motion analysis system using commercially available digital video capture. The first testing protocol involved developing a method to evaluate system spatial performance characteristics with respect to accuracy, precision, and resolution. A physical model comprising a calibration frame was constructed with phantom postures selected to represent joint angles and off-plane movement typical of the activities of interest. This provided reference angles to which angles measured from digitally captured images were compared using the Bland and Altman method. Validation experiments confirmed that the principal sources of error were due to off-plane motion and pixel resolution in the video capture and analysis systems. In these analyses, it was verified that simulated experimental conditions could be corrected using the direct linear transform (DLT); however, the removal of parallax still resulted in 2 degrees of error in measured joint angles. The main source of error was resolution of the data acquisition system verified through Monte Carlo simulations. The second testing protocol involved developing a simple method to determine the temporal accuracy of motion analysis systems incorporating digital video cameras and a pendulum. A planar column pendulum with a natural frequency of 0.872 Hz was used to analyse five systems incorporating commercially available cameras and a single codec. The frame rate for each camera was measured to be within 3% of the US National Television Systems Committee (NTSC) broadcasting digital video standard of 29.97 fps.; however some cameras produced a frame duplication artefact. Least squares curve-fitting using a sinusoidal function revealed RMS differences between 3-5% for angular position and 5-15% for angular speed compared to the captured motion data. It was shown that some digital-video cameras and computer playback software contain data compression technology that may produce substantial temporal frame inaccuracies in recovered video sequences and that temporal accuracy should be evaluated in digital-based human motion analysis systems prior to their use in experimentation. / Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2009-08-14 10:54:58.685

The rapid growth of wireless systems has shown little sign of ceasing, due to increased consumer demand for reliable interactive services. A key component of the development has centered on satellite networks, which allows provision of services in scenarios where terrestrial systems are not viable. The Digital Video Broadcasting-Satellite Second Generation (DVB-S2) standard was developed for use in satellite broadcast applications, the foremost being video broadcasting. Inherent to DVB-S2 is a powerful forward error correction (FEC) module, present in both the Physical and Data Link Layer. Improving the error correcting capability of the FEC is a natural advent in improving the quality of service of the protocol. This is more crucial in real time satellite video broadcast where retransmission of data is not viable, due to high latency. The Physical Layer error correcting capability is implemented in the form of a concatenated BCH-LDPC code. The DVB-S2 standard does not define the decoding structure for the receiver system however many powerful decoding systems have been presented in the literature; the Belief Propagation-Chase concatenated decoder being chief amongst them. The decoder utilizes the concept of soft information transfer between the Chase and Belief Propagation (BP) decoders to provide improved error correcting capability above that of the component decoders. The following dissertation is motivated by the physical layer (PL) FEC scheme, focused on the concatenated Chase-BP decoder. The aim is to generate results based on the BP-Chase decoder in a satellite channel as well as improve the error correcting capability. The BP-Chase decoder has shown to be very powerful however the current literature provides performance results only in AWGN channels. The AWGN channel however is not an accurate representation of a land-mobile satellite (LMS) channel; it does not consider the effect of shadowing, which is prevalent in satellite systems. The development of Markov chain models have allowed for better description of the characteristics of the LMS channel. The outcome being the selection of a Ku band LMS channel model. The selected LMS channel model is composed of 3 states, each generating a different degree of shadowing. The PL system has been simulated using the LMS channel and BP-Chase receiver to provide a more accurate representation of performance of a DVB-S2 network. The effect of shadowing has shown to reduce coding performance by approximately 4dB, measured over several code lengths and decoders, when compared with AWGN performance results. The second body of work aims to improve the error correcting capability of the BP-Chase decoder, concentrating on improving the LDPC decoding module performance. The LDPC system is the basis for the powerful error correcting ability of the concatenated scheme. In attempting to improve the LDPC decoder a reciprocal improvement is expected in the overall decoding performance of the concatenated decoder. There have been several schemes presented which improve BP performance. The BP-Ordered statistics decoder (OSD) was selected through a process of literary review; a novel decoding structure is presented incorporating the BP-OSD decoder into the BP-Chase structure. The result of which is the BP-OSD-Chase decoder. The decoder contains two stages of concatenation; the first stage implements the BPOSD algorithm which decodes the LDPC code and the second stage decodes the BCH code using the Chase algorithm. Simulation results of the novel decoder implementation in the DVBS2 PL show a coding gain of 0.45dB and 0.15dB versus the BP and BP-Chase decoders respectively, across both the AWGN and LMS channel. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2012.

In this thesis, we propose a new method for content-aware resizing of videos in real- time. Our approach consists of two steps. First, we compute a set of non-salient pixels in linear time which, when being removed or duplicated, do not alter the general appearance of the video. This is an extension of Avidan and Shamir's [3] greedy seam-carving approach to video. Second, we generate a new representation of the video, so called multi-view videos that allow us to resize the video in real-time, i.e. while being watched. This representation can be computed very effciently, the complexity is linear in the number of frames and linear in the number of pixels in a video. Our technique works on a broad variety of videos and is computationally inexpensive enough to be executed by a vast range of devices. We compare our technique to our own implementation of a current state-of-the-art approach and show several convincing results obtained by our technique.

The aim of this investigation was to examine the role of visual elements in second language listening comprehension when digital video was used as a mode of presentation. Despite the widespread use of video in listening instruction, little is known at present about how learners attend to dual-coded media and, in particular, how visual elements may influence comprehension processes. (For complete abstract open document)

Thesis (Ph.D.)--University of Melbourne, Dept. of Linguistics and Applied Linguistics, 1999. / Typescript (photocopy). Includes bibliographical references (p. 287-305).

Thesis (Ph.D.)--Australian Defence Force Academy, School of Electrical Engineering, 2003. / "October 2002 (Revised May 2003)"--T.p. Includes bibliographical references (leaves 256-264).

Thesis (Ph.D.)--University of Wollongong, 2005. / Typescript. Includes bibliographical references: leaf 223-249.

Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2008. / Includes bibliographical references (leaves 57-62). Also available in electronic version.

Thesis (Ph.D.)--Hong Kong University of Science and Technology, 2008. / Includes bibliographical references (leaves 140-149). Also available in electronic version.

Thesis (Ph.D.) - Simon Fraser University, 2005. / Theses (School of Computing Science) / Simon Fraser University.