Showing items 35681 - 35700 of 63285

Siyakholwa kuThixo

- Zimbabwe mass participants, Composer not specified, Dargie, Dave

Siyakholwa kuThixo

- Zimbabwe mass participants, Composer not specified, Dargie, Dave

Siyam'bulela uThixo

- Ngaba, David, Composer Not Specified, Dargie, Dave

Siyambulel' uThixo

- Music festival participants, Hirmer, O., Composer not specified, Dargie, Dave

Siyambulel' uThixo

- Zimbabwe mass participants, Composer not specified, Dargie, Dave

Siyambulel' uThixo

- Music festival participants, Hirmer, O., Composer not specified, Dargie, Dave

Some aspects of the construction and implementation of error-correcting linear codes

- Booth, Geoffrey L

  • Authors: Booth, Geoffrey L
  • Date: 1978
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:20967 , http://hdl.handle.net/10962/5718
  • Description: From Conclusion: The study of error-correcting codes is now approximately 25 years old. The first known publication on the subject was in 1949 by M. Golay, who later did much research into the subject of perfect codes. It has been recently established that all the perfect codes are known. R.W. Hamming presented his perfect single-error correcting codes in 1950, in ~n article in the Bell System Technical Journal. These codes turned out to be a special case of the powerful Bose-Chaudhuri codes which were discovered around 1960. Various work has been done on the theory of minimal redundancy of codes for a given error-correcting performance, by Plotkin, Gilbert, Varshamov and others, between 1950 and 1960. The binary BCH codes were found to be so close to the theoretical bounds that, to date, no better codes have been discovered. Although the BCH codes are extremely efficient in terms of ratio of information to check digits, they are not easily, decoded with a minimal amount of apparatus. Petersen in 1961 described an algorithm for d e coding BCH codes, but this was cumbersome compared with the majority-logic methods of Massey and others. Thus the search began for codes which are easily decoded with comparatively simple apparatus. The finite geometry codes which were described by Rudolph in a 1964 thesis were examples of codes which are easily decoded 58 by a small number of steps of majority logic. The simplicial codes of Saltzer are even better in this respect, since they can be decoded by a single step of majority logic, but are rather inefficient . The applications of coding theory have changed over the years, as well. The first computers were huge circuits of relays, which were unreliable and prone to errors. Error correcting codes were required to minimise the possibility of incorrect results. As vacuum tubes and later transistorised circuits made computers more reliable, the need for sophisticated and powerful codes in the computer world diminished. Other used presented themselves however, for example the control systems of unmanned space craft. Because of the difficulty of sending and receiving messages in this case, · very powerful codes were required. Other uses were found in transmission lines and telephone exchanges. The codes considered in this dissertation have, for the most part, been block codes for use on the binary symmetric channel. There are, however, several other applications, such as codes for use on an erasure channel, where bits are corrupted so as to be unrecognizable, rather than changed. There are also codes for burst-error correction, where chennel noise is not randomly distributed, but occurs in "bursts" a few bits long. Certain cyclic codes are of application in these cases. The theory of error correcting codes has risen from virtual non-existence in 1950 to a major and sophisticated part of communication theory. Judging from the articles in journals, it promises to be the subject of a great deal of research for some years to come.
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  • Date Issued: 1978

Some principles of communicating effectively through press advertisements with Blacks

- Koekemoer, Ludi

Some reflections on academic freedom

- Slabbert, Frederik van Zyl, 1940-2010

  • Authors: Slabbert, Frederik van Zyl, 1940-2010
  • Date: 1978
  • Subjects: Academic Freedom -- South Africa
  • Language: English
  • Type: text
  • Identifier: http://hdl.handle.net/10962/186 , vital:19934
  • Description: The purpose of this meeting is as I see it, twofold: a reaffirmation of a commitment and a protest. We once again declare our commitment to the principle of academic freedom and we protest that a very important aspect of this freedom has been infringed upon in the University’s relationships with the Government. The nature of this infringement is enshrined in the Extension of University Education Act of 1959. Since then other statutory and legal provisions were introduced which affected traditional civil liberties such as the freedom of speech, the rule of law, freedom of association etc. which apply not only to Universities but to our society in general. How these provisions affect the academic freedom of Universities is argued very adequately in the booklet “The Open Universities and Academic Freedom in S. A. 1957- 1974” produced by the Academic Freedom Committees of the Universities of Cape Town and Witwatersrand. I am not going to use this occasion to repeat those arguments. All of them make the same central point namely: that it is not the function of the Government to prescribe who should be admitted as students to a University, who shall be appointed to teach and what shall be taught. At the outset then I want to make it clear that I subscribe to this principle and as long as the Government persists with infringing it I believe it is worthy of our objection and protest. For almost twenty years now this protest has been made annually at some of our so-called “open” Universities.
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  • Date Issued: 1978

Spatial autocorrelation and the analysis of patterns resulting from crime occurrence

- Ward, Gary J

  • Authors: Ward, Gary J
  • Date: 1978
  • Subjects: Geography -- Statistical methods , Correlation (Statistics) , Spatial analysis (Statistics) , Criminal statistics -- South Africa -- Grahamstown
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:4864 , http://hdl.handle.net/10962/d1007244
  • Description: From Introduction: In geography during the 1950's there was a definite move away from the study of unique phenomena to the study of generalized phenomena or pattern (Mather and Openshaw, 1974). At the same time interrelationships between phenomena distributed in space and time became the topic of much interest among geographers, as well as members of other disciplines. The changing emphasis initiated acceptance of certain scientific principles (Cole, 1973), and mathematical techniques became the recognized and respected means through which objective analysis of pattern, structure, and interrelationships between a really distributed phenomena could be achieved (Ackerman, 1972; Burton, 1972; Gould, 1973). Geographers, as do members of other disciplines, frequently borrow mathematical techniques developed for problems encountered in the pure sciences and apply these techniques to what are felt to be analogous situations in geography.
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  • Date Issued: 1978

Studies in ionospheric ray tracing

- Lambert, Sheridan

  • Authors: Lambert, Sheridan
  • Date: 1978 , 2013-10-21
  • Subjects: Ionosphere -- Research -- Graphic methods , Ionospheric radio wave propagation -- Research , Ionograms , Ray tracing algorithms
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:5501 , http://hdl.handle.net/10962/d1006906 , Ionosphere -- Research -- Graphic methods , Ionospheric radio wave propagation -- Research , Ionograms , Ray tracing algorithms
  • Description: The use of ray tracing in the analysis of certain daytime ionograms recorded at Grahamstown is discussed in this thesis. A computer program has been modified and used to trace rays in the frequency range 1 - 30 MHz. Vertical, short distance oblique, and long distance oblique ionograms have been synthesized from the results and compared with experimental ionograms for Grahamstown, the Alice - Grahamstown transmission path (64 km), and the SANAE - Grahamstown transmission path (4470 km) respectively. Ray paths have been calculated and related in detail to the models of the ionosphere and geomagnetic field. The main features of the vertical and short distance oblique ionograms can, in general, be reproduced using spherically stratified ionosphere models with electron density profiles derived from vertical ionograms. A suitable model for the geomagnetic field is a tilted dipole equivalent to the actual field at Grahamstown. The two-hop mode is shown to be, usually, the lowest on the long distance oblique records. The ionosphere model is the principal limiting factor in reproducing such ionograms, and the most satisfactory results have been those obtained with a model in which electron density is assumed to vary linearly with latitude between the profiles at SANAE and Grahamstown. The promising results obtained by ray tracing with normal ionospheric conditions indicate that the method has further possibilities which could usefully be explored. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
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  • Date Issued: 1978

Studies on the fermentation of molasses by Clostridium acetobutylicum

- Barber, Jennifer Mary

  • Authors: Barber, Jennifer Mary
  • Date: 1978
  • Subjects: Molasses , Clostridium acetobutylicum , Fermentation
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:4084 , http://hdl.handle.net/10962/d1007611 , Molasses , Clostridium acetobutylicum , Fermentation
  • Description: The bacterium Clostridium acetobutylicum produces acetone and n [subscript] - butanol from molasses in an industrial fermentation system. Although the bacterium has been cultured in liquid media it does not grow well on agar plates and requires high concentrations of hydrogen. Pretreatment of agar plates with bovine catalase improves growth on agar media. The bacteria produce an area of clearing (halo) on Potato agar plates due to butyric acid (the precursor of n [subscript]-butanol) and ß -amylase production. This characteristic will be used as a plate screening assay for the selection of high solvent producing mutants. A laboratory scale fermentation system was developed and detailed studies including pH, turbidity and cell morphology changes, and the details of solvent production were undertaken. The fermentation was optimized for mutant selection. The production of normal solvent yields by isolated clones is required for the mutant selection programme. Studies revealed that sporulation of the clones increased their solvent yield although solvent yields were still lower than normal. Efficient sporulation is therefore a prerequisite for clone fermentation. The origin of the phage infection during the factory outbreak was determined and resistant clones obtained. The presence of a bacteriocin-like toxin causing decreases in turbidity was identified during the final fermentation stage. The strain sensitivity, optimum conditions for stability as well as the kinetics of inactivation and lethality have been investigated. Preliminary characterization and purification studies indicate the proteinaceous nature of the toxin. , KMBT_363
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  • Date Issued: 1978

Studies on the metabolism of SKF 525 A|

- Barber, Peter John

  • Authors: Barber, Peter John
  • Date: 1978 , 2013-10-14
  • Subjects: Drugs -- Metabolism , Cytochrome P-450
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:3835 , http://hdl.handle.net/10962/d1007591 , Drugs -- Metabolism , Cytochrome P-450
  • Description: Spectrophotometric studies have been carried out to determine the pH dependence of binding of SKF 525 A, Brietal sodium and carbon monoxide to cytochrome P-450. The optimal pH for metabolic conversion of SKF 525 A has been investigated and this agent and its major metabolite, SKF 8742 A, have been metabolised in vitro by swine and rat hepatic microsomes. A suitable gas liquid chromatography assay has been developed and used to analyse metabolic production. The effects of carbon monoxide, dithiothreitol, n-octylamine and of induction of cytochrome P-450 by phenobarbital on metabolism of SKF 525 A and SKF 8742 A have been investigated. Attempts have been made to synthesise SKF 525 AN-oxide. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
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  • Date Issued: 1978

Taru Thixo

- Xhosa festival workshop participants, Meyi, M., Dargie, Dave

Thathaini izipho

- Music workshop participants, Deyi, Joseph, Dargie, Dave

Thathani izipho

- Music workshop participants, Composer not specified, Dargie, Dave

Thathani izipho

- Zulu church music workshop participants, Deyi, Jospeh, Dargie, Dave

The anatomy of the triassic theropod Syntarsus rhodesiensis (Saurischia : Podokesauridae) and a consideration of its biology

- Raath, M A

  • Authors: Raath, M A
  • Date: 1978
  • Subjects: Reptiles, Fossil Dinosaurs Paleontology -- Triassic , Dinosaurs , Fossils , Reptiles , Palaeontology , Triassic period
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:5601 , http://hdl.handle.net/10962/d1002051
  • Description: The osteology of the Upper Triassic podokesaurid Syntarsus rhodesiensis is described, based on a series of 30+ individuals representing all skeletal elements, recovered since the description of the holotype (Raath, 1969). A brief account of the geology of the finds is given, with an attempt at a reconstruction of the palaaoenvironment. The excellence of preservation of the bones has permitted an attempt at the restoration of soft tissues including the brain, cranial nerves, main cranial blood vessels and the musculature of the jaws, neck and limbs. Histological sections of limb bones have shown that the compact bone was highly vascular, and this, together with the structure of the brain, palaeoenvironmental considerations, social behaviour and group structure, leads to the conclusion that Syntarsus was an endothermic homeotherm inhabiting a hot arid region at the end of the Triassic, with a social organisation into "flocks" in which females predominated numerically. Clear evidence of sexual dimorphism is presented. Syntarsus is reconstructed as a bipedal, saltatorial predator which differs in subtle, but probably generically significant, characteristics from the closely related North American genus, Coelophysis. Its anatomy characterises it as a medium-sized agile animal with a highly kinetic skull; incipiently opposable pollex in the raptorial manus; highly cursorial hindlimb; and with features in the dentition and hallux which suggest a grooming function. It is concluded that the Triassic coelurosaurian stock provided an advanced and well adapted base from which the successful coelurosaur radiation into the later Mesozoic sprang, and that this stock was physiologically pre-adapted for the emergence of the avian (and possibly the pterosaur) lineages in the Jurassic
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  • Date Issued: 1978

The Bondelswarts Rebellion of 1922

- Lewis, Gavin, 1954-

  • Authors: Lewis, Gavin, 1954-
  • Date: 1978
  • Subjects: Bondelswarts (African people) , Namibia -- Race relations , Namibia -- History
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:2589 , http://hdl.handle.net/10962/d1006957 , Bondelswarts (African people) , Namibia -- Race relations , Namibia -- History
  • Description: The rebellion was the result of many and varied Bondelswarts grievances, accumulating into discontent. The attempted arrest of Morris and the bungling of subsequent negotiations was the last straw. Their distrust, fear and suspicion of the Government, built up from German times, made any negotiations doubly difficult. They were a proud people, proud of their history and traditions, and proud of their tribal identity. Their days of complete independence were not long gone, and only in the early 1920's was there any appreciable white settlement in their area. It was then, while they watched their lands being irrevocably divided up amongst whites, that with the increased white settlement came stricter and more burdensome laws. In some respect, the rebellion was the last stand of a people driven to frustration and poverty. It was indeed, as Freislich calls it, the last tribal war. They fought a futile battle against the inexorable advance of white technology and civilization, and in this sense their ultimate revolt was perhaps inevitable (Conclusion: p. 229-230)
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  • Date Issued: 1978

The climax of a life's work-Tretchikoff.

- Tretchikoff, Vladimir

  • Authors: Tretchikoff, Vladimir
  • Date: 1978
  • Subjects: UNCATALOGUED
  • Type: Image
  • Identifier: http://hdl.handle.net/10962/236909 , vital:50462 , DTC-119
  • Description: Clipping of Vladimir Tretchikoff's exhibition , Use of this resource is governed by the terms and conditions of the Creative Commons "Attribution-NonCommercial-ShareAlike" License (http://creativecommons.org/licenses/by-nc-sa/2.0/) (NEVER CAHNGE THIS FIELD)
  • Full Text: false
  • Date Issued: 1978
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