Browsing by Author "Du Plessis, Andre"

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    Adapting a historical dictionary for the modern online user : the case of the dictionary of South African English on historical principles's presentation and navigation features
    (Bureau of the WAT, 2016) Du Plessis, Andre; Van Niekerk, Tim
    A collaboration between the Dictionary Unit for South African English (DSAE) and Stellenbosch University (SU) was initiated in 2016 to address the structure, layout and functionality of the online Dictionary of South African English on Historical Principles (DSAEHist). This article focuses on work undertaken during the initial stages of the DSAE-SU collaboration and presents current work in adapting a print historical dictionary for the digital age. As with other print dictionaries that enter the electronic medium, the pilot version of the online DSAEHist still felt and looked like a print dictionary, albeit with a somewhat more user-friendly access structure. Another difficulty that the DSAEHist faces is the need for a dictionary based on historical principles to showcase large diachronic datasets. This requires that the article and microstructure, as well as the access structure, be adapted. Apart from this, the general layout of the dictionary is also being re-evaluated and redesigned to make it more usable on online platforms. To accommodate new users and to bring the DSAEHist into the digital era (with regard to standard web and mobile practices) stylistic, navigational and functional changes are being made. This article presents these changes to show how a valuable cultural and language resource is being brought into the digital era.
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    On two combinatorial optimisation problems involving lotteries
    (Stellenbosch : University of Stellenbosch, 2010-03) Du Plessis, Andre; Van Vuuren, J. H.; Burger, A. P.; University of Stellenbosch. Faculty of Economic and Management Sciences. Dept. of Logistics.
    ENGLISH ABSTRACT: Suppose a lottery draw consists of forming a winning ticket by randomly choosing t m distinct numbers from a universal set Um = f1; : : : ;mg. Each lottery participant forms a set of tickets prior to the draw, each ticket consisting of n m distinct numbers from Um, and is awarded a prize if k minfn; tg or more numbers in at least one of his/her tickets matches those of the winning ticket. A lottery of this form is denoted by the quadruple hm; n; t; ki, and the prize is known as a k-prize. The participant's set of tickets is also known as a playing set. The participant may wish to form a playing set in such a way that the probability of winning a k-prize is at least 0 < 1. Naturally, the participant will want to minimise the cost of forming such a playing set, which means that the cardinality of the playing set should be as small as possible. This combinatorial minimisation problem is known as the incomplete lottery problem and was introduced by Gr undlingh [16], who also formulated a related problem called the resource utilisation problem. In this problem one attempts to select a playing set of pre-speci ed cardinality ` in such a way that the probability of winning a k-prize is maximised. Gr undlingh [16] studied the incomplete lottery problem and the resource utilisation problem in the special case where n = t. In this thesis both problems are considered in the general case where n 6= t. Exact and approximate solution methods are presented and compared to each other in terms of solution quality achieved, execution time and practical feasibility. The rst solution method involves a mathematical programming formulation of both problems. Using this solution method, both problems are solved for small lottery instances. An exhaustive enumeration solution method, which uses the concept of overlapping playing set structures [5, 16], is reviewed and used to solve both combinatorial optimisation problems for the same small lottery instances. The concept of an overlapping playing set structure is further explored and incorporated in an attempt to solve both combinatorial optimisation problems approximately by means of various metaheuristic solution approaches, including a simulated annealing algorithm, a tabu search and a genetic algorithm. The focus of the thesis nally shifts to a di erent problem involving lotteries. An investigation is conducted into the probability, P(N; ), of participants sharing a k-prize if a total of N tickets are purchased by participants of the lottery hm; n; t; ki. Special attention is a orded in this problem to the jackpot prize of the South African national lottery, Lotto, represented by the quadruple h49; 6; 6; 6i and how the value of P(N; ) is a ected by the way that participants select their playing sets.
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    Towards linking user interface translation needs to lexicographic theory
    (Bureau of the WAT, 2015) Du Plessis, Andre; Swart, Marius
    In a time of proliferating electronic devices such as smartphones, translators of user interfaces are faced with new challenges, such as the use of existing words in new contexts or in their obtaining new meanings. In this article, three lexicographic reference works available to translators in this field are compared: the Kuberwoordeboek/Cyber Dictionary (Viljoen 2006), the Pharos Afrikaans–Engels/English–Afrikaans Dictionary (Du Plessis et al. 2010) and the Microsoft Language Portal (www.microsoft.com/Language 2015). A list of selected examples (in English) is used to determine the extent to which each of these three works fulfils the needs of the user in terms of meaning discrimination for translating into Afrikaans. After determining this, an attempt is made to indicate whether the use of meaning discriminators such as part-of-speech markers, punctuation, paraphrases of meaning, and contextual and co-textual guidance (as indicated by Beyer 2009: 11) may have contributed to the success or failure of the given reference work, in order to arrive at a conclusion about the link between lexicographic theory and usability.