ETD Collection

Permanent URI for this collectionhttps://wiredspace.wits.ac.za/handle/10539/104


Please note: Digitised content is made available at the best possible quality range, taking into consideration file size and the condition of the original item. These restrictions may sometimes affect the quality of the final published item. For queries regarding content of ETD collection please contact IR specialists by email : IR specialists or Tel : 011 717 4652 / 1954

Follow the link below for important information about Electronic Theses and Dissertations (ETD)

Library Guide about ETD

Browse

Filters

2008 - 20102

Settings

Subject: search.filters.subject.Sampling

Search Results

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Sound art in Johannesburg: a critical review 2005-2009
    (2010-06-28T09:55:38Z) Engelbrecht, B.J.
    ABSTRACT In this dissertation I offer a critical review of ‘sound art’ in Johannesburg between 2005 and 2009. The term ‘sound art’ was coined by Dan Lander in 1989. According to Christoph Cox, Dan Lander’s lament that sound art lacked “any substantial discourse” in 1989 still applied in 2007. My intention in this research is to start such a critical discourse for sound art in Johannesburg. I argue that sound art is a distinctive practice in the city, involving the body politic and underground, surface and edge as characterised by Achille Mbembe and Sarah Nuttall in their recent major work on Johannesburg. First I briefly consider the history of sound art, referring to Brandon Labelle’s view that this history parallels that of site-specific art. I then suggest that the popularity of sound art under review became popular for a number of reasons; what Walter Ong’s termed “a shift in the sensorium”, the immediacy and inexpensiveness of working with sound, and the rise of the home computer. I also locate the sonic practices constituting sound art in audio culture as a whole, focussing on the structure, materiality, recording, playback and transmission of the sonic event in the sonic landscape. Sound, silence, noise and music are all part of this focus. I finally examine sound in terms of space, time, body and network in the work of Frances Goodman, Siobhan McCusker, The Trinity Session, Teamuncool, Gerhard Marx and my own sound work involving sampling, Happy Station (2008) and Slice Me Nice (2009).
  • No Thumbnail Available
    Item
    Assessing the usefulness of sample survey designs and census data with respect to poverty mapping in Ethiopia
    (2008-06-27T11:40:27Z) Gebretsadik, Alemayehu
    We investigated the effect of different probability sampling designs (simple random sampling, stratified, cluster and systematic sampling designs) on estimates of age, gender proportions, and proportions of the population with different education levels, and access to water. To investigate the effect of the sample designs we used as a sampling frame the census 1994 data obtained from Central Statistical Agency of Ethiopia (CSA). In order to compare results obtained from different sampling designs, estimates of population means and proportions for selected variables at household levels using 1, 5 and 10% sample size is considered. The performance of these sampling techniques is observed on the following dimensions: relative accuracy, standard error, confidence intervals, precision and also we compared the effect of the different methods of calculating variances like Taylor series and jack-knife, the comparison of this two methods is done by drawing 100 different samples of 1% for stratified and cluster sampling. It was found that in general the relative accuracy for the selected variable obtained from the stratified sampling design is better than other estimates. We also find evidence that the 95% confidence interval constructed for each method contains the true population value, but the confidence interval for cluster sample is wider than the others that indicate less precision than others. The result of the comparison of the different methods of estimating the variance from the simulated population variance indicates that, for cluster sampling, both of the Taylor linearization and jack-knife methods tend to overestimate the population variance, whereas for stratified sampling the population standard error is in between of the standard error of the both methods indicating when one underestimates the other overestimates. Design effects were also compared, and it was found that the design effect for cluster sampling was larger that for the other methods, as expected. Survey cost information is needed to further inform discussion of the usefulness of the different methods. We assessed the extent of poverty by calculating the poverty index for the Tigray region. To calculate the poverty index we used the method proposed by the United Nations Development Programme (UNDP). Using the Welfare/Poverty Monitoring Survey year 2000 (WMS2000) data obtained from CSA, we found that the region is highly affected by each of the dimensions investigated. Further questions need to be added to questionnaires in order to allow use of the census data in calculating poverty maps.