Field testing the Alvarion BreezeMAX as a last mile access technology
- Authors: Siebörger, Ingrid , Terzoli, Alfredo
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428520 , vital:72517 , https://www.researchgate.net/profile/Ingrid-Sieboerger/publication/255048217_Field_testing_the_Alvarion_BreezeMAX_as_a_last_mile_access_technology/links/53ff2f290cf21edafd15bfad/Field-testing-the-Alvarion-BreezeMAX-as-a-last-mile-access-technology.pdf
- Description: With an alarmingly low teledensity of approximately 12% in South Afri-ca, and not much hope of further wired infrastructure at the local loop level–as the costs incurred are high compared to potential revenue–wireless connectivity could be a great asset and service in South Africa. This paper looks at how WiMAX technologies, and specifically the Al-varion BreezeMAX, could be used in providing much needed telecom-munications infrastructure to both rural and urban areas in South Africa, providing broadband data throughput rates together with excellent net-work reliability and low latency.
- Full Text:
- Date Issued: 2007
Computer Networks: CSC 323
- Authors: Sibanda, K , Vogts, D
- Date: 2011-01
- Language: English
- Type: Examination paper
- Identifier: vital:17757 , http://hdl.handle.net/10353/d1010290
- Description: Computer Networks: CSC 323, Supplementary examination January/February 2011.
- Full Text: false
- Date Issued: 2011-01
Using an RTSP Proxy to implement the IPTV Media Function via a streaming server
- Authors: Shibeshi, Zelalem S , Terzoli, Alfredo , Bradshaw, Karen L
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429120 , vital:72561 , https://ieeexplore.ieee.org/abstract/document/5676629
- Description: Multimedia in IMS, including IPTV, is handled by a separate unit, the Media Function (MF), which is made up of Media Control and Media Delivery Functions (MCF and MDF). According to the different specifications of an IMS based IPTV architecture, the User Equipment (UE) is expected to use the RTSP protocol as a media control protocol to interact with the MCF, and gets delivery of media from the MDF using the RTP protocol. This generally means that the streaming session is initiated from the media controller on behalf of the user but the delivery of media is sent to the UE from the media deliverer (media server). Due to lack of free and open source Media Servers and on the contrary, the availability of free and open source Streaming Servers, the ideal choice for the delivery of media in multimedia services, including IPTV, by the research community are Streaming Servers. Nevertheless, because of denial of service attack and other issues, most streaming servers do not allow different locations for the session setup request and the delivery of media of the streaming session. This makes it difficult to have a separate media control unit for IPTV service in IMS, if one wants to use a streaming server as an MDF unit. For this purpose we propose another component (an RTSP proxy and relay unit) to be part of the IPTV Media Function (MF). The unit will be used to mediate between the MFC and MDF and will properly relay media control (RTSP) commands from the UE and MFC to the MDF and RTP packets from the MDF to the UE. This, we believe, will facilitate the development of an IPTV service using readily available open source streaming servers. In this paper we show how this RTSP proxy and relay unit can be integrated into the Media Function of the IPTV architecture to ease the media delivery process of IMS based IPTV service.
- Full Text:
- Date Issued: 2010
Hybrid Sensor Simulation within an ICS Testbed
- Authors: Shaw, Brent , Irwin, Barry V W
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427713 , vital:72457 , https://www.researchgate.net/profile/Barry-Ir-win/publication/327624204_Hybrid_Sensor_Simulation_within_an_ICS_Testbed/links/5b9a50d8299bf14ad4d79587/Hybrid-Sensor-Simulation-within-an-ICS-Testbed.pdf
- Description: Industrial Control Systems (ICS) are responsible for managing factories, power-grids and water treatment facilities, and play a key role in running and controlling national Critical Information Infrastructure (CII). The integrity and availability of these systems are paramount, and the threat of cyberphysical attacks on these systems warrant thorough research into ensuring their security. The increasing interconnectivity seen in both the domestic and industrial sectors exposes numerous devices and systems to the Internet. These devices are exposed to malware and advanced persistent threats, that can affect CII through the attack of ICS. While simulations provide insights into how systems might react to certain changes, they generally lack the ability to be integrated into existing hardware systems. Hybrid testbeds could provide a platform for testing hardware and software components, enabling researchers to examine the interactions between various different networking through exploratory research and investigation in a controlled environment. This work presents an approach to traffic generation for use within ICS/IoT testbeds, through the production of Docker-based simulation nodes that are constructed based on the configuration of the system.
- Full Text:
- Date Issued: 2018
Making the Invisible Visible: Ameliorating Poverty through Natural Resource Commercialisation
- Authors: Shackleton, Sheona E
- Date: 2009
- Language: English
- Type: text
- Identifier: vital:6618 , http://hdl.handle.net/10962/d1016226
- Description: [From Introduction] The majority of households in South Africa, especially those in the rural communal areas, live in abject poverty. Some 70% of rural households can be classified as poor, while 18-24% fall into the chronically poor category. Unlike many other developing nations, South Africa's rural communal areas are characterised by relatively poor availability of agricultural land, with only about 40% of rural households involved in field cropping. This results in high levels of integration and dependence on the cash economy. Unemployment levels are amongst the highest in the world at about 30%. Unemployment amongst women tends to be greater than amongst men resulting in a poverty rate amongst rural female-headed households of over 60%; double that of male-headed households. The scourge of HIV/AIDS is devastating already poor households' ability to cope. More than half of HIV/AIDS affected households have insufficient food (UNDP 2003). Impacts of the pandemic include not only the loss of income, but also increased expenditure particularly on medical care and funerals. The need to care for ill household members or orphaned children also limits the choices of occupation that other household members can pursue, and may restrict labour availability for food production. Household assets are often sold for cash eroding the few safety nets people have. HIV/AIDS is expected to contribute to a chronic impoverishment of 26-33% more households than would be the case in its absence (Aliber 2003). , Endnote: This policy brief is based on the original brief made available for a workshop in August 2006. It is derived, amongst other sources, from the findings of nine case studies of local natural resource commercialisation undertaken as part of a project funded by the South Africa-Netherlands Programme on Alternatives in Development (SANPAD), BP South Africa and the National Research Foundation (NRF). Case studies on woodcraft, furniture production, weaving, broom production and the sale of wild foods and traditional marula beer were completed by Zwoitwa Makhado (UWC), Sibongile Mavimbela (Rhodes), Taryn Pereira (Rhodes), Sheona Shackleton (Rhodes) and Jabulile Sithole (WSU). CIFOR with support from SIDA, provided the funding to share these findings with key stakeholders. The opinions expressed in these policy briefs are those of the author and research team and should not necessarily be attributed to funders and partner institutions.
- Full Text:
- Date Issued: 2009
Ameliorating poverty in South Africa through natural resource commercialisation
- Authors: Shackleton, Sheona E
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6651 , http://hdl.handle.net/10962/d1007062
- Description: This short policy brief advocates for more attention to be paid to the potential of natural resource commercialisation as a means to livelihood security and poverty alleviation in rural South Africa. It is one of a set of four policy briefs based on the findings of several case studies across the country.
- Full Text:
- Date Issued: 2006
Street trees contribute to urban sustainability in South African towns
- Authors: Shackleton, Charlie M , Gwedla, Nanamhla
- Date: 2017
- Subjects: City planning -- Environmental aspects Sustainable urban development Community development -- Environmental aspects -- South Africa
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/54269 , vital:26440
- Description: Urban green spaces and trees are increasingly recognised as crucial elements in the quest for urban sustainability internationally, and for the promotion of urban liveability and quality of life in cities. So much so that many countries now have guidelines or regulations regarding either the amount of urban greenery that must be provided per capita, or the maximum distance that any dwelling can be from green spaces of stipulated sizes. For example, the European Union recently more than doubled its recommendation of 9 m2 of public green per person to 20 m2 per person.
- Full Text:
- Date Issued: 2017
Promoting indigenous vegetables in urban agriculture & livelihoods : policy lessons from Sub-Saharan Africa
- Authors: Shackleton, Charlie M , Pasquini, Margaret W , Ambrose-Oji, Bianca , Drescher, Axel W
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6619 , http://hdl.handle.net/10962/d1016227
- Description: [From Introduction] Globally, the growth of urbanised areas continues at an exponential rate, and most spectacularly in the developing world. The global urban population will increase from 2.9 billion in 2000 to 5.0 billion by 2030. The mean rate of urban growth in non-OECD countries between 2000 and 2005 was just under 3% per annum, compared to 0.5 % for rural regions of the same countries (UN-Habitat 2006). Although the proportion of Africans currently living in urban areas is the lowest in the world (+ 40%), because of this low base it is not unsurprising that the rates of urbanisation are among the highest at approximately 4.3% per annum. Projections vary, but sometime in the mid- 2020s over 50% of Africa's population will be living in urban areas, as compared to just 15% in 1950 and 34% in 1994. As urbanisation takes place another important trend is revealed, namely the locus of poverty in Africa is slowly shifting from rural to urban areas. For example, it is estimated that more than 56% of the world's absolute or chronic poor will be concentrated in urban areas (WRI 1996). Since as much as 60-80% of the income of the urban poor is spent on the purchase of food (Maxwell et al. 2000), the issue of food supply, both its quantity and quality, is increasingly a central issue in poverty reduction debates and strategies. In rural areas, a common strategy to alleviate poverty is to call for measures to boost small-holder food production. Surprisingly, this is less common in urban poverty alleviation programmes, despite the widespread promise of urban and household agriculture in contributing to improved food security.
- Full Text:
- Date Issued: 2009
Academic Practices and Reasoning: APR 111
- Authors: Scott,R , Blatchford, M
- Date: 2012-06
- Language: English
- Type: Examination paper
- Identifier: vital:18270 , http://hdl.handle.net/10353/d1011266
- Description: Academic Practices and Reasoning: APR 111, special examination June 2012.
- Full Text: false
- Date Issued: 2012-06
Academic Practices and Reasoning: APR 122
- Authors: Scott, R , Blatchford, M
- Date: 2010-01
- Language: English
- Type: Examination paper
- Identifier: vital:18236 , http://hdl.handle.net/10353/d1011228
- Description: Academic Practices and Reasoning: APR 122, Jan/Feb supplementary examination 2010.
- Full Text: false
- Date Issued: 2010-01
Academic Practices and Reasoning: APR 122
- Authors: Scott, R , Blatchford, M
- Date: 2009-11
- Language: English
- Type: Examination paper
- Identifier: vital:18273 , http://hdl.handle.net/10353/d1011269
- Description: Academic Practices and Reasoning: APR 122, examination November 2009.
- Full Text: false
- Date Issued: 2009-11
Academic Practices & Reasoning: APR 122
- Authors: Scott, R , Blatchford, M
- Date: 2011-01
- Language: English
- Type: Examination paper
- Identifier: vital:18248 , http://hdl.handle.net/10353/d1011242
- Description: Academic Practices and Reasoning: APR 122, supplementary examination Jan/Feb 2012.
- Full Text: false
- Date Issued: 2011-01
Communication and Life Skills: CLS 111F
- Authors: Scott, R , Formson, C
- Date: 2011-06
- Language: English
- Type: Examination paper
- Identifier: vital:18316 , http://hdl.handle.net/10353/d1011440
- Description: Communication and Life Skills: CLS 111F, examination June 2011.
- Full Text: false
- Date Issued: 2011-06
Academic Practices and Reasoning: APR 122
- Authors: Scott, R , Blatchford, M
- Date: 2012-01
- Language: English
- Type: Examination paper
- Identifier: vital:18252 , http://hdl.handle.net/10353/d1011246
- Description: Academic Practices and Reasoning: APR 122, supplementary examination January 2012.
- Full Text: false
- Date Issued: 2012-01
Data Structures and Algorithms: CSC 223
- Authors: Scott, M S , Sibanda, K
- Date: 2012-01
- Language: English
- Type: Examination paper
- Identifier: vital:17761 , http://hdl.handle.net/10353/d1010294
- Description: Data Structures and Algorithms: CSC 223, degree examinations January 2012.
- Full Text: false
- Date Issued: 2012-01
Spermatophore dimorphism in the chokka squid Loligo reynaudii associated with alternative mating tactics
- Authors: Sato, Noriyosi , Iwata, Yoko , Shaw, Paul W , Sauer, Warwick H H
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/127070 , vital:35952 , https://doi.10.1093/mollus/eyy002
- Description: Chokka squid (Loligo reynaudii) have characteristic alternative mating tactics: ‘consort’ males temporarily pair with and guard a female and transfer spermatophores onto her oviduct opening inside the mantle cavity, whereas ‘sneaker’ males rush towards a mating pair and transfer spermatophores onto the female’s buccal membrane near her sperm storage organ. Differences in mating behaviours and their related sperm-storage sites clearly constrain the fertilization process and can drive dimorphism between consort and sneaker males. The presence and character of male dimorphism has not yet been fully examined in this species, but consort males are commonly much larger than sneaker males. We observed clear dimorphism in spermatangia (the sperm mass ejaculated from the spermatophore), consistently associated with the two alternative sperm storage sites on the female’s body. Observations of spermatophores stored in the Needham’s sac of mature males confirmed that small males produce ‘sneaker-type’ spermatangia whereas larger males produce ‘consort-type’ spermatangia, and no individuals possessed both types. Therefore, by association, the mating tactic adopted (including the sperm deposition site used) by individual males can be determined from observation of their spermatangial type, without requiring direct behavioural observation of mating. This ability to infer information about mating tactic will improve our understanding of the reproductive system and mating dynamics in this species.
- Full Text:
- Date Issued: 2018
Psychopathology and Counselling Psychology: PSY 311
- Authors: Sandlana, N S , Marais, R , Young, C
- Date: 2012-01
- Language: English
- Type: Examination paper
- Identifier: vital:18016 , http://hdl.handle.net/10353/d1010593
- Description: Psychopathology and Counselling Psychology: PSY 311, special examination January 2012.
- Full Text: false
- Date Issued: 2012-01
Analysis of the calling songs of Platypleura hirtipennis (Germar, 1834) and P. plumosa (Germar, 1834) (Hemiptera: Cicadidae)
- Authors: Sanborn, Allen F , Phillips, P K , Villet, Martin H
- Date: 2003
- Language: English
- Type: text , Article
- Identifier: vital:6896 , http://hdl.handle.net/10962/d1011656
- Description: [From the introduction]: Most male cicadas produce a calling song in order to attract conspecific females. These songs have been shown to differ in closely related species (e.g. Alexander & Moore 1962; Villet 1988, 1989; Boulard 1995; Marshall & Cooley 2000; Sanborn & Phillips 2001) and in species which share habitats (e.g. Sueur 2002). The former is an inevitable part of the divergence of recognition signals that characterizes the speciation process in animals using acoustic signals (Villet 1995), while the latter would be expected from a signal that acts as a reproductive isolating mechanism (Claridge 1985; Marshall & Cooley 2000). Calling songs are therefore of value in resolving taxonomic problems in the cicadas.
- Full Text:
- Date Issued: 2003
Research Methodology: IPS 515
- Authors: Samuel, M O , Berry, D M
- Date: 2011-08
- Subjects: Research -- Methodology
- Language: English
- Type: Examination paper
- Identifier: vital:17483 , http://hdl.handle.net/10353/d1010449
- Description: Research Methodology: IPS 515, examination August 2011.
- Full Text: false
- Date Issued: 2011-08
SADTU draft input on WHITE PAPER No. 5 on early childhood development
- Authors: SADTU
- Date: 2001
- Subjects: SADTU
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/176156 , vital:42665
- Description: SADTU welcomes the release of White Paper No. 5 on Early Childhood Development. We thank the Ministry and Department of Education for affording us this opportunity to make an input. We are however concerned that the process during its development excluded stakeholder participation.
- Full Text:
- Date Issued: 2001