483 resultados para digital audio production
Resumo:
In 1993 the Australian Broadcasting Corporation was contracted by the Australian Government to assist in the reshaping of the South African Broadcasting Corporation from a state-run broadcaster to a respected and trusted national broadcaster for all people in the newly democratic South Africa. Broadcast journalism training was identified by ABC consultant Bob Wurth as possibly the greatest need for SABC Radio. This thesis examines the ABC's role in South Africa and the effectiveness of its radio journalism training project considering the organisational, structural, cultural and political constraints of the SABC. This thesis will show through interviews and participant observation the difficulties in achieving the production of Western Liberal journalism values at the SABC within the time constraints set by the project funded by the Australian Government and the particular South African morays.
Resumo:
This thesis investigates aspects of encoding the speech spectrum at low bit rates, with extensions to the effect of such coding on automatic speaker identification. Vector quantization (VQ) is a technique for jointly quantizing a block of samples at once, in order to reduce the bit rate of a coding system. The major drawback in using VQ is the complexity of the encoder. Recent research has indicated the potential applicability of the VQ method to speech when product code vector quantization (PCVQ) techniques are utilized. The focus of this research is the efficient representation, calculation and utilization of the speech model as stored in the PCVQ codebook. In this thesis, several VQ approaches are evaluated, and the efficacy of two training algorithms is compared experimentally. It is then shown that these productcode vector quantization algorithms may be augmented with lossless compression algorithms, thus yielding an improved overall compression rate. An approach using a statistical model for the vector codebook indices for subsequent lossless compression is introduced. This coupling of lossy compression and lossless compression enables further compression gain. It is demonstrated that this approach is able to reduce the bit rate requirement from the current 24 bits per 20 millisecond frame to below 20, using a standard spectral distortion metric for comparison. Several fast-search VQ methods for use in speech spectrum coding have been evaluated. The usefulness of fast-search algorithms is highly dependent upon the source characteristics and, although previous research has been undertaken for coding of images using VQ codebooks trained with the source samples directly, the product-code structured codebooks for speech spectrum quantization place new constraints on the search methodology. The second major focus of the research is an investigation of the effect of lowrate spectral compression methods on the task of automatic speaker identification. The motivation for this aspect of the research arose from a need to simultaneously preserve the speech quality and intelligibility and to provide for machine-based automatic speaker recognition using the compressed speech. This is important because there are several emerging applications of speaker identification where compressed speech is involved. Examples include mobile communications where the speech has been highly compressed, or where a database of speech material has been assembled and stored in compressed form. Although these two application areas have the same objective - that of maximizing the identification rate - the starting points are quite different. On the one hand, the speech material used for training the identification algorithm may or may not be available in compressed form. On the other hand, the new test material on which identification is to be based may only be available in compressed form. Using the spectral parameters which have been stored in compressed form, two main classes of speaker identification algorithm are examined. Some studies have been conducted in the past on bandwidth-limited speaker identification, but the use of short-term spectral compression deserves separate investigation. Combining the major aspects of the research, some important design guidelines for the construction of an identification model when based on the use of compressed speech are put forward.
Resumo:
This dissertation develops the model of a prototype system for the digital lodgement of spatial data sets with statutory bodies responsible for the registration and approval of land related actions under the Torrens Title system. Spatial data pertain to the location of geographical entities together with their spatial dimensions and are classified as point, line, area or surface. This dissertation deals with a sub-set of spatial data, land boundary data that result from the activities performed by surveying and mapping organisations for the development of land parcels. The prototype system has been developed, utilising an event-driven paradigm for the user-interface, to exploit the potential of digital spatial data being generated from the utilisation of electronic techniques. The system provides for the creation of a digital model of the cadastral network and dependent data sets for an area of interest from hard copy records. This initial model is calibrated on registered control and updated by field survey to produce an amended model. The field-calibrated model then is electronically validated to ensure it complies with standards of format and content. The prototype system was designed specifically to create a database of land boundary data for subsequent retrieval by land professionals for surveying, mapping and related activities. Data extracted from this database are utilised for subsequent field survey operations without the need to create an initial digital model of an area of interest. Statistical reporting of differences resulting when subsequent initial and calibrated models are compared, replaces the traditional checking operations of spatial data performed by a land registry office. Digital lodgement of survey data is fundamental to the creation of the database of accurate land boundary data. This creation of the database is fundamental also to the efficient integration of accurate spatial data about land being generated by modem technology such as global positioning systems, and remote sensing and imaging, with land boundary information and other information held in Government databases. The prototype system developed provides for the delivery of accurate, digital land boundary data for the land registration process to ensure the continued maintenance of the integrity of the cadastre. Such data should meet also the more general and encompassing requirements of, and prove to be of tangible, longer term benefit to the developing, electronic land information industry.
Resumo:
This work is a digital version of a dissertation that was first submitted in partial fulfillment of the Degree of Doctor of Philosophy at the Queensland University of Technology (QUT) in March 1994. The work was concerned with problems of self-organisation and organisation ranging from local to global levels of hierarchy. It considers organisations as living entities from local to global things that a living entity – more particularly, an individual, a body corporate or a body politic - must know and do to maintain an existence – that is to remain viable – or to be sustainable. The term ‘land management’ as used in 1994 was later subsumed into a more general concept of ‘natural resource management’ and then merged with ideas about sustainable socioeconomic and sustainable ecological development. The cybernetic approach contains many cognitive elements of human observation, language and learning that combine into production processes. The approach tends to highlight instances where systems (or organisations) can fail because they have very little chance of succeeding. Thus there are logical necessities as well as technical possibilities in designing, constructing, operating and maintaining production systems that function reliably over extended periods. Chapter numbers and titles to the original thesis are as follows: 1. Land management as a problem of coping with complexity 2. Background theory in systems theory and cybernetic principles 3. Operationalisation of cybernetic principles in Beer’s Viable System Model 4. Issues in the design of viable cadastral surveying and mapping organisation 5. An analysis of the tendency for fragmentation in surveying and mapping organisation 6. Perambulating the boundaries of Sydney – a problem of social control under poor standards of literacy 7. Cybernetic principles in the process of legislation 8. Closer settlement policy and viability in agricultural production 9. Rate of return in leasing Crown lands