A convenient approach to the deterministic routing of MIDI messages
- Authors: Shaw, Brent Roy
- Date: 2018
- Subjects: MIDI (Standard) , Microcontrollers , XMOS Limited , Computer architecture , Embedded computer systems
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/63256 , vital:28387
- Description: This research investigates the design and development of a Wireless MIDI Connection Management solution in order to create a deterministic MIDI transmission system. A investigation of the MIDI protocol show it to have certain limitation that can be overcome through the use of transmission solutions. These solutions can be used to improve on the versatility of MIDI while overcoming the MIDI's notorious cable length limitation. XMOS's deterministic XS1 microcontrollers are used to enable the design of a real-time system. The MIDINet system is investigated to identify both the strengths and weaknesses of such a connection management system, while other systems for network transmission of MIDI messages are reviewed. These investigations lead to a design concept for a new network MIDI transmission system that allows for the remote management of connections. The design and subsequent implementation of both the transmission system and the connection management system are then detailed. A testing methodology is then devised to allow for the newly created connection management system to be compared to the MIDINet system. The findings show the deterministic system to have lower latency than that of the MIDINet system, while utilising more compact and power efficient hardware.
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- Date Issued: 2018
Preimages for SHA-1
- Authors: Motara, Yusuf Moosa
- Date: 2018
- Subjects: Data encryption (Computer science) , Computer security -- Software , Hashing (Computer science) , Data compression (Computer science) , Preimage , Secure Hash Algorithm 1 (SHA-1)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/57885 , vital:27004
- Description: This research explores the problem of finding a preimage — an input that, when passed through a particular function, will result in a pre-specified output — for the compression function of the SHA-1 cryptographic hash. This problem is much more difficult than the problem of finding a collision for a hash function, and preimage attacks for very few popular hash functions are known. The research begins by introducing the field and giving an overview of the existing work in the area. A thorough analysis of the compression function is made, resulting in alternative formulations for both parts of the function, and both statistical and theoretical tools to determine the difficulty of the SHA-1 preimage problem. Different representations (And- Inverter Graph, Binary Decision Diagram, Conjunctive Normal Form, Constraint Satisfaction form, and Disjunctive Normal Form) and associated tools to manipulate and/or analyse these representations are then applied and explored, and results are collected and interpreted. In conclusion, the SHA-1 preimage problem remains unsolved and insoluble for the foreseeable future. The primary issue is one of efficient representation; despite a promising theoretical difficulty, both the diffusion characteristics and the depth of the tree stand in the way of efficient search. Despite this, the research served to confirm and quantify the difficulty of the problem both theoretically, using Schaefer's Theorem, and practically, in the context of different representations.
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- Date Issued: 2018
The design and assessment of an integrated municipal waste beneficiation facility : towards improved sewage sludge management in developing countries
- Authors: Keirungi, Juliana
- Date: 2007
- Subjects: Sewage -- Purification -- South Africa -- Eastern Cape , Sewage sludge -- South Africa -- Eastern Cape -- Management , Water quality management -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4755 , http://hdl.handle.net/10962/d1007138 , Sewage -- Purification -- South Africa -- Eastern Cape , Sewage sludge -- South Africa -- Eastern Cape -- Management , Water quality management -- South Africa -- Eastern Cape
- Description: This research aimed to firstly confirm the hypothesis that the current management of sewage sludge generated during the treatment of wastewater in the Eastern Cape Province of South Africa is poor and, as such, this material poses a threat to local environmental and human health. Secondly, through a rational design approach, the current research also aimed to design and assess the suitability of a novel integrated process incorporating appropriate technologies for improved sewage sludge management. The lack of an appropriate tool for the assessment of the integrated process necessitated the development of an appropriate technology assessment (TA) methodology based on environmental, technical, social and economic criteria. A combination of informal participatory methods such as semi-structured interviews and formal research methods including questionnaires, risk assessment exercises and laboratory analyses were used. Based on the above it was estimated that 116 tons dry sludge were generated in the province per day and that the concentration of heavy metals present in the sludge was generally within the limits for reuse on agricultural land. Furthermore the sludge from all sample sewage treatment works (STWs) was found to be free of any detectable pathogens. Despite the above, a preliminary risk assessment and chemical analysis revealed that existing sludge management practices at sample STWs posed a threat to the environment, particularly to water resources and exacerbated the problems associated with the discharge of poorly treated municipal wastewater. The root causes of the poor sludge management were considered to be a lack of non-regulatory incentives and financial resources. Highly integrated ecologically engineered systems were thought to offer a solution to the dual problem of poor sludge management and municipal effluent treatment, while providing necessary economic incentives. To facilitate the design of a system appropriate to local conditions, it was necessary to first develop a rational design methodology, which incorporated a detailed TA step. The result of the design process was an Integrated Waste Beneficiation Facility (IWBF) that incorporated a number of process units comprised of appropriate technologies including composting, vermicomposting, algal ponding technology and aquaculture. A detailed TA indicated that the benefits of the proposed IWBF would, at the majority of sample sites, outweigh the potential negative impacts and it was thus recommended that investigations should continue on pilot-scale facilities. Furthermore, although the proposed TA based on four sustainability criteria categories was thought to provide a more accurate assessment of the true sustainability of a technology, the acquisition of information was problematic highlighting the need to re-think current TA methodologies and to address associated constraints allowing the tool to be used and fully comprehensive.
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- Date Issued: 2007
A preliminary investigation into the patterns of performance on a computerized adaptive test battery implications for admissions and placement
- Authors: Vorster, Marlene
- Date: 2002
- Subjects: Universities and colleges -- Admission , Advanced placement programs (Education) , Computer adaptive testing , Universities and colleges -- Entrance requirements
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:11030 , http://hdl.handle.net/10948/285 , Universities and colleges -- Admission , Advanced placement programs (Education) , Computer adaptive testing , Universities and colleges -- Entrance requirements
- Description: The fallibility of human judgment in the making of decisions requires the use of tests to enhance decision-making processes. Although testing is surrounded with issues of bias and fairness, it remains the best means of facilitating decisions over more subjective alternatives. As a country in transition, all facets of South African society are being transformed. The changes taking place within the tertiary education system to redress the legacy of Apartheid, coincide with an international trend of transforming higher education. One important area that is being transformed relates to university entrance requirements and admissions procedures. In South Africa, these were traditionally based on matriculation performance, which has been found to be a more variable predictor of academic success for historically disadvantaged students. Alternative or revised admissions procedures have been implemented at universities throughout the country, in conjunction with academic development programmes. However, it is argued in this dissertation that a paradigm shift is necessary to conceptualise admissions and placement assessment in a developmentally oriented way. Furthermore, it is motivated that it is important to keep abreast of advances in theory, such as item response theory (IRT) and technology, such as computerized adaptive testing (CAT), in test development to enhance the effectiveness of selecting and placing learners in tertiary programmes. This study focuses on investigating the use of the Accuplacer Computerized Placement Tests (CPTs), an adaptive test battery that was developed in the USA, to facilitate unbiased and fair admissions, placement and development decisions in the transforming South African context. The battery has been implemented at a university in the Eastern Cape and its usefulness was investigated for 193 participants, divided into two groups of degree programmes, depending on whether or not admission to the degree required mathematics as a matriculation subject. Mathematics based degree programme learners (n = 125) wrote three and non-mathematics based degree programme learners (n = 68) wrote two tests of the Accuplacer test battery. Correlations were computed between the Accuplacer scores and matriculation performance, and between the Accuplacer scores, matriculation performance and academic results. All yielded significant positive relationships excepting for the one subtest of the Accuplacer with academic performance for the non-mathematics based degree group. Multiple correlations for both groups indicated that the Accuplacer scores and matriculation results contribute unique information about academic performance. Cluster analysis for both groups yielded three underlying patterns of performance in the data sets. An attempt was made to validate the cluster groups internally through a MANOVA and single-factor ANOVAs. It was found that Accuplacer subtests and matriculation results do discriminate to an extent among clusters of learners in both groups of degree programmes investigated. Clusters were described in terms of demographic information and it was determined that the factors of culture and home language and how they relate to cluster group membership need further investigation. The main suggestion flowing from these findings is that an attempt be made to confirm the results with a larger sample size and for different cultural and language groups.
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- Date Issued: 2002
Ambivalence and paradox: the battered woman's interactions with the law and other helping resources
- Authors: Labe, Dana
- Date: 2001
- Subjects: Family violence -- Law and legislation , Abused women , Family violence , Wife abuse , Women -- Crimes against , Women -- Counseling of , Family violence -- Prevention
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3333 , http://hdl.handle.net/10962/d1003127 , Family violence -- Law and legislation , Abused women , Family violence , Wife abuse , Women -- Crimes against , Women -- Counseling of , Family violence -- Prevention
- Description: This thesis explores how the battered woman attachment to her abusive partner impacts on her interactions with the legal system and non-legal resources. This qualitative research project is based on in-depth interviews conducted with seven abused women who procured interdicts in terms of the Prevention of Family Violence Act 133 of 1993 to restrain their husbands from assaulting them. The research reviews the nature of abuse suffered by the participants, their psychological attachments to their husbands, and their patterns of help-seeking in relation to the law and non-legal resources. Two main theoretical frameworks, psychoanalysis and feminism inform this study. The study found that the participants retained unrealistic hopes that their husbands would reform and become loving, caring partners, and that they treated their husbands with care and sympathy despite their husbands’ often brutal behaviour towards them. The findings suggest that the women’s behaviour towards their husbands was the product of two reality distorting psychological defences, splitting and the moral defence which they used to preserve their attachments to their abusive partners. These defences intersected with rigid patriarchal prescriptions of femininity which dictate that women should be stoically caring towards their husbands, and should hold relationships together no matter what the cost to themselves. The participants interactions with the legal system and with non-legal sources of help were structured by their reliance on splitting and the moral defence, and by the dictates of patriarchal ideology. Whilst it is undoubtedly true that at one level the participants sought help to get protection from abuse, the study shows that their help-seeking was motivated by their conflicting desires to punish and reform their husbands. The participants sought help in ways which enabled them to strike a compromise between expressing their anger at their husbands, whilst simultaneously preserving their psychological attachments to them. The study concludes that the women’s interactions with the law and with other helping resource reflect their attempts to preserve their paradoxical attachments to their husbands, and to stabilise their own fragile sense of self and gender identity.
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- Date Issued: 2001
At play in the master's workshop: the experience of reading in the novels of Henry James
- Authors: Seddon, Deborah Ann
- Date: 1998
- Subjects: James, Henry, 1843-1916 -- Criticism and interpretation
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2278 , http://hdl.handle.net/10962/d1007451 , James, Henry, 1843-1916 -- Criticism and interpretation
- Description: James's belief that "it is art that makes life" is essential to his own literary technique and to the reading experience within and in relation to his novels. The thesis seeks to posit the notion of reading as a fundamental concern in Henry James's fiction. Drawing largely on the phenomenological and anthropological approaches to the reading process of Wolfgang Iser, this thesis examines the Jamesian text as a performative event involving author, reader and character in creative and interpretative narrational struggles. Iser uses "play" as an integral term to describe the dynamic between author-reader-text which produces a literary work of art. In James's fiction the doubling of the author/reader and reader/character role within the text crucially structures a narrative form which is itself an inquiry into the human use of fiction. The Iserian conception of the act of reading as an engagement with the "gaps" within the play-space of the literary text can elucidate James's structural and thematic use of such sites of indeterminacy to foreground the enlivening necessity of an indeterminate "felt life" within human narrative structures. What Maisie Knew highlights the most important rule in the game -- the necessity for the reader to create meaning from the indeterminate aspects of the text. The shared exercise for author-reader-character is the attempt to access the child's unformulated inner reality to ascertain what Maisie knows. In the section on The Portrait of a Lady Iser's notion of reading as an ideational activity aids an inquiry into the human use of mental fictive picturing to compose reality. The Ambassadors demonstrates the "anthropological" need for the particular mode of consciousness brought about by the literary text when we engage in a world as real as but different to our own. Strether is the reader's ambassador in this world and his interpretative activity mirrors the reader's quest. In The Golden Bowl the bewildering multiplicity of readings made possible by the indeterminate aspects of the literary text instigates a contest for narrative forms in which the chosen fictions of the readers/characters must be actively willed into existence.
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- Date Issued: 1998
"Rest and unrest": some rural and romantic themes in the poetry of Edward Thomas
- Authors: Lagan, Charles J
- Date: 1985-12
- Subjects: Thomas, Edward, 1878-1917 , Thomas, Edward, 1878-1917 -- Criticism and interpretation , English poetry -- 20th century
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2264 , http://hdl.handle.net/10962/d1004770 , Thomas, Edward, 1878-1917 , Thomas, Edward, 1878-1917 -- Criticism and interpretation , English poetry -- 20th century
- Description: From Preface: The scope and focus of this thesis has been determined by the fact that I have tried to present a thematic, though not exhaustive, account of the poetry of Edward Thomas. (I have analysed a representative selection of the poems.) Much has been written on his life and poetry in this past decade to coincide with the centenary of his birth which was celebrated in 1978. Edna Longley, William Cooke and more recently, Andrew Motion have thrown much light on his poetry and I am indebted to them. I acknowledge especially the work of Edna Longley; her Edward Thomas: Poems and Last Poems, though it does not include all the poems, has proved to be an invaluable source because of the many extracts from Thomas's prose incorporated into her notes on his poems. Her book is also rich in suggestive insights into Thomas's poetry. Unfortunately not all of Thomas's works are available in South Africa. On a brief visit overseas I tried without success to obtain the more important books not available here. I have had to make use of anthologies of Thomas's prose where a particular text was not available, for example, In Pursuit of Spring and The South Country. I thank Ms Yolisa Soul who through the Inter Library Loan services of the University of Fort Hare managed to obtain for me a substantial number of Thomas's prose works.
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- Date Issued: 1985-12