The topic of this thesis presents a digital front end (DFE) of the digital video broadcasting over terrestrial (DVB-T). The DVB-T system is similar to most of the prior digital communication system. It is roughly divided into two major parts, one for channel coding/decoding, and the other for modulation/demodulation. The thesis is mainly focused on the DVB-T digital video broadcasting demodulation part of the receiver and the integration of a complete digital front demodulation system. The major operational processor of the DFE is a 2K/8K dual-mode FFT processor, which has been implemented by the TSMC ( Taiwan Semiconductor Manu-facturing Company ) 0.35um 2P4M CMOS process technology to justify the simulation results as well as the correctness of the proposed architecture.

This thesis includes two topics. The first one is a low-power double-edge triggered flip-flop.The other is a orthogonal frequency division multiplex (OFDM) demodulator compliant with the Digital Video Broadcasting Handheld (DVB-H). Low-power double-edge triggered flip-flop (DETFF) is based on multi-Vth transistors technique. Since low threshold voltage transistors are able to generate large leakage current, they are suitable to drive big loads. By contrast, high threshold voltage transistors are more appropriate to latch data due to their low leakage. Therefore, a single latch double-edge triggered flip-flop utilizing multi-Vth transistors can be a low power and high speed design without paying the price of large area. The proposed OFDM demodulator is compliant with the DVB-H standard. The received DVB-H signal is processed by an RF front-end and the following analog-to-digital converter. Then, the digital signal is fed into the demodulator to adjust and calibrate the frequency, timing offset and channel estimation. The proposed DVB-H demodulator is mainly composed of five blocks : symbol timing synchronization block, carrier frequency offset compensation block, fast Fourier transform block, scatter pilot detection block and channel compensation block.

This thesis presents methods and a system for video search over the internet or the intranet. The objective is to design a real time and automated video clustering and search system that provides users of the search engine the most relevant videos available that are responsive to a query at a particular moment in time, and supplementary information that may also be useful. The thesis highlights methods to mitigate the effect of the semantic gap faced by current content based video search approaches. A context-sensitive video ranking scheme is used, wherein the context is generated in an automated manner.

The objective of this dissertation is to present a detection-based pattern recognition framework and demonstrate its applications in automatic speech recognition and broadcast news video story segmentation. Inspired by the studies of modern cognitive psychology and real-world pattern recognition systems, a detection-based pattern recognition framework is proposed to provide an alternative solution for some complicated pattern recognition problems. The primitive features are first detected and the task-specific knowledge hierarchy is constructed level by level; then a variety of heterogeneous information sources are combined together and the high-level context is incorporated as additional information at certain stages. A detection-based framework is a â divide-and-conquerâ design paradigm for pattern recognition problems, which will decompose a conceptually difficult problem into many elementary sub-problems that can be handled directly and reliably. Some information fusion strategies will be employed to integrate the evidence from a lower level to form the evidence at a higher level. Such a fusion procedure continues until reaching the top level. Generally, a detection-based framework has many advantages: (1) more flexibility in both detector design and fusion strategies, as these two parts can be optimized separately; (2) parallel and distributed computational components in primitive feature detection. In such a component-based framework, any primitive component can be replaced by a new one while other components remain unchanged; (3) incremental information integration; (4) high level context information as additional information sources, which can be combined with bottom-up processing at any stage. This dissertation presents the basic principles, criteria, and techniques for detector design and hypothesis verification based on the statistical detection and decision theory. In addition, evidence fusion strategies were investigated in this dissertation. Several novel detection algorithms and evidence fusion methods were proposed and their effectiveness was justified in automatic speech recognition and broadcast news video segmentation system. We believe such a detection-based framework can be employed in more applications in the future.

Over-height trucks are not only a hazard to the over-height trucks themselves, but they pose a threat to the bridges they come into contact with, and most importantly the other drivers on the road way when a collision takes place with a low clearance structure. Therefore, there is a need for an over-height detection system that is affordable yet also reliable. At this time there exist over-height detection systems using laser and infrared beam devices however, they are expensive. This high cost makes it impossible for Department of Transportations across the nation to implement these systems at all low-clearance headroom roadways. In this research a machine vision based system is proposed to detect the height of trucks and provide a warning for over-height vehicles. The height determination will be completed using line detection and blob tracking; these two methods will be overlapped where an upper point of the truck can be compared to a lower point on the ground. These 2D coordinates will then be translated into 3D world coordinates that will provide an approximation of the truck height. If the truck is over the set height then a warning will sound. The accuracy of the test proves that the method is a reliable method of height determination, achieving a 96.59% accuracy rate for measured trucks. The method does have an error rate of 3.3%. The merit of this work is the creation of an automatic image based method which can provide height determination of trucks and is a low cost alternative to the current expensive laser and infrared detection systems.

<p>Transmission of digital signals is today more frequently used than transmission of analog signals. One reason for this is that a digital signal is less sensitive to noise than an analog, another reason is that almost all signals today are handled in a digital format. This thesis describes the development of a system that receives digital video signals through FireWire. The standard for FireWire, which is a high performance serial bus, is under development. Today the standard of the bus supports transmission of data with a speed of up to 400 Mbit/s. In the future FireWire is supposed to transmit data with a speed of up to 3,2 Gbit/s. The thesis gives an introduction to the technique for FireWire and how it is implemented. It also includes a short description of digital video signals in DVCAM format.</p>

Originally presented as the author's thesis--Universität Hannover. / Includes bibliographical references.

Thesis (Ph.D)--Electrical and Computer Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Yucel Altunbasak; Committee Member: Brani Vidakovic; Committee Member: Ghassan AlRegib; Committee Member: James Hamblen; Committee Member: Russ Mersereau. Part of the SMARTech Electronic Thesis and Dissertation Collection.

This research investigates the development of digital video filmmaking in West Africa using Ghana and Burkina Faso as case studies within the context of new technologies. The key research questions that guided the study were how do the economic, social and political contexts of video filmmaking affect the development of a digital video film industry in Ghana and Burkina Faso? and how have the perceptions of digital technologies (held by filmmakers and other stakeholders) impacted upon the development of digital video film making in West Africa? Using field interviews with stakeholders in the video film industry in Ghana and Burkina Faso, as well as with the West African diaspora community in the UK, document research, textual references, and personal observation, the research discusses the challenges of new digital and video technologies, and their implications for the development of the video film industry. The research establishes that video and digital technologies are offering many people the opportunity to make films. There is however, a plethora of new digital technologies that enable the work of video film producers, which require closer examination. The research suggests that the impact of the digital revolution has been limited, and a number of factors account for this. The study offers recommendations that might contribute to discussions on finding solutions to the development of a professional, regulatory and practical video filmmaking environment. This would lead to the formulation of policies that impact positively on filmmaking in the region, and consequently increase the capacity of local productions to compete on the international film scene.

My ethnography explores the independent documentary film community in Songzhuang, an artist village in Beijing's Tongzhou District. Through participant-observation, interviews, participation in festivals, and my own filmmaking practice, I describe filmmakers and festival organizers as cultural producers endeavoring to work outside the confines of both the government and the mainstream cinema industry. To offer an analysis of the social, political, economic, and ethical conditions of this independent film community, my study also focuses on concrete practices of filmmakers and film supporters; privately-owned centers and social networks that enable the production, exhibition, and distribution of films; and the relationship between this community and government regulation. I argue that the independent documentary community constitutes a jianghu (literally, “rivers and lakes”), which, drawing from Chinese literature, I delimit as a social world of marginality and resistance against the status quo. Further, jianghu refers not only to independent filmmakers, but also to millions of “migrants” within the Chinese population who, even as they provide labor that fuels development, nonetheless subsist on the margins. This study also considers the efforts of filmmakers and scholars to elucidate a Chinese visual aesthetic, which has been called xianchang (“on the spot”) and, most recently, jingguan dianying (“quiet observational cinema”). These indigenous framings counter eurocentric notions of documentary and prevail among the majority of independent directors as an aesthetic wellsuited to represent the “cruelty of the social,” a term I introduce to describe social suffering born not only of China’s modern history of pain but also its contemporary turbulent era. I draw together the issues of distribution, social impact, and economic stability for independent documentary, as well as document the role of the state in quelling, censoring, and co-opting independent film. I conclude by exploring xianchang and my own filmmaking practice as advancing a form of knowledge that, owing to its experiential quality and its refusal to simplify and reduce phenomena into cultural data, is well-suited to represent the inherent complexity of Chinese society. Finally, a coda documents recent government oppression and festival cancellations to argue that the current moment is one of grave uncertainty for Chinese independent film. / Anthropology