Distribution of benthic diatom communities in a permanently open temperate estuary in relation to physico-chemical variables
- Dalu, Tatenda, Richoux, Nicole B, Froneman, P William
- Authors: Dalu, Tatenda , Richoux, Nicole B , Froneman, P William
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67943 , vital:29172 , https://doi.org/10.1016/j.sajb.2015.06.004
- Description: Publisher version , The spatial and temporal patterns in benthic diatom community structure in temperate permanently open estuaries are poorly understood. In this study, we used a combination of multivariate and diversity indices to elucidate environmental factors associated with diatom community structure in the Kowie Estuary, South Africa. Benthic diatom samples were collected from three sites corresponding to the upper, middle and lower reaches of the estuary on four occasions over the period early spring 2012 to winter 2013. Among the 89 benthic diatoms observed, Entomoneis paludosa (W Smith) Reimer, Nitzschia reversa W Smith, Nitzschia closterium (Ehrenberg) W Smith, Pleurosigma elongatum W Smith, P. salinarum (Grunow) Grunow, Staurosira elliptica (Schumann) DM Williams & Round, Surirella brebissonii Krammer & Lange-Bertalot, and Surirella ovalis Brébisson were the numerically dominant species. Principal component analysis demonstrated that the diatom community structure was determined by a variety of factors including nutrient (ammonia, nitrate) concentrations, hydrology (e.g., water depth and flow) and pH. Hierarchical cluster analysis revealed the absence of any distinct spatial patterns, although distinct benthic diatom communities were recorded during the different sampling periods. The species richness was highest in the middle reach, decreasing from early spring to summer in all reaches. The results of the study provide important insights into the various factors that structure benthic diatom community composition within a permanently open temperate southern African estuary.
- Full Text: false
- Date Issued: 2016
- Authors: Dalu, Tatenda , Richoux, Nicole B , Froneman, P William
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67943 , vital:29172 , https://doi.org/10.1016/j.sajb.2015.06.004
- Description: Publisher version , The spatial and temporal patterns in benthic diatom community structure in temperate permanently open estuaries are poorly understood. In this study, we used a combination of multivariate and diversity indices to elucidate environmental factors associated with diatom community structure in the Kowie Estuary, South Africa. Benthic diatom samples were collected from three sites corresponding to the upper, middle and lower reaches of the estuary on four occasions over the period early spring 2012 to winter 2013. Among the 89 benthic diatoms observed, Entomoneis paludosa (W Smith) Reimer, Nitzschia reversa W Smith, Nitzschia closterium (Ehrenberg) W Smith, Pleurosigma elongatum W Smith, P. salinarum (Grunow) Grunow, Staurosira elliptica (Schumann) DM Williams & Round, Surirella brebissonii Krammer & Lange-Bertalot, and Surirella ovalis Brébisson were the numerically dominant species. Principal component analysis demonstrated that the diatom community structure was determined by a variety of factors including nutrient (ammonia, nitrate) concentrations, hydrology (e.g., water depth and flow) and pH. Hierarchical cluster analysis revealed the absence of any distinct spatial patterns, although distinct benthic diatom communities were recorded during the different sampling periods. The species richness was highest in the middle reach, decreasing from early spring to summer in all reaches. The results of the study provide important insights into the various factors that structure benthic diatom community composition within a permanently open temperate southern African estuary.
- Full Text: false
- Date Issued: 2016
Economic evaluation of water loss saving due to the biological control of water hyacinth at New Year’s Dam, Eastern Cape province, South Africa
- Fraser, Gavin C G, Hill, Martin P, Martin, J A
- Authors: Fraser, Gavin C G , Hill, Martin P , Martin, J A
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69341 , vital:29502 , https://doi.org/10.2989/16085914.2016.1151765
- Description: Water hyacinth Eichhornia crassipes is considered the most damaging aquatic weed in the world. However, few studies have quantified the impact of this weed economically and ecologically, and even fewer studies have quantified the benefits of its control. This paper focuses on water loss saving as the benefit derived from biological control of this plant between 1990 and 2013 at New Year’s Dam, Alicedale, Eastern Cape, South Africa. Estimates of water loss due to evapotranspiration from water hyacinth vary significantly; therefore, the study used three different rates, high, medium and low. A conservative raw agriculture value of R 0.26 per m3 was used to calculate the benefits derived by the water saved. The present benefit and cost values were determined using 10% and 5% discount rates. The benefit/cost ratio at the low evapotranspiration rate was less than one, implying that biological control was not economically viable but, at the higher evapotranspiration rates, the return justified the costs of biological control. However, at the marginal value product of water, the inclusion of the costs of damage to infrastructure, or the adverse effects of water hyacinth on biodiversity, would justify the use of biological control, even at the low transpiration rate.
- Full Text: false
- Date Issued: 2016
- Authors: Fraser, Gavin C G , Hill, Martin P , Martin, J A
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69341 , vital:29502 , https://doi.org/10.2989/16085914.2016.1151765
- Description: Water hyacinth Eichhornia crassipes is considered the most damaging aquatic weed in the world. However, few studies have quantified the impact of this weed economically and ecologically, and even fewer studies have quantified the benefits of its control. This paper focuses on water loss saving as the benefit derived from biological control of this plant between 1990 and 2013 at New Year’s Dam, Alicedale, Eastern Cape, South Africa. Estimates of water loss due to evapotranspiration from water hyacinth vary significantly; therefore, the study used three different rates, high, medium and low. A conservative raw agriculture value of R 0.26 per m3 was used to calculate the benefits derived by the water saved. The present benefit and cost values were determined using 10% and 5% discount rates. The benefit/cost ratio at the low evapotranspiration rate was less than one, implying that biological control was not economically viable but, at the higher evapotranspiration rates, the return justified the costs of biological control. However, at the marginal value product of water, the inclusion of the costs of damage to infrastructure, or the adverse effects of water hyacinth on biodiversity, would justify the use of biological control, even at the low transpiration rate.
- Full Text: false
- Date Issued: 2016
Evaluating the multi-threading countermeasure
- Frieslaar, Ibrahim, Irwin, Barry V W
- Authors: Frieslaar, Ibrahim , Irwin, Barry V W
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428352 , vital:72505 , https://researchspace.csir.co.za/dspace/bitstream/handle/10204/9041/Frieslaar_2016.pdf?sequence=1andisAllowed=y
- Description: This research investigates the resistance of the multi-threaded coun-termeasure to side channel analysis (SCA) attacks. The multi-threaded countermeasure is attacked using the Correlation Power Analysis (CPA) and template attacks. Additionally, it is compared to the existing hiding countermeasure. Furthermore, additional signal processing techniques are used to increase the attack success ratio. It is demon-strated that the multi-threaded countermeasure is able to outperform the existing countermeasures by withstanding the CPA and template at-tacks. Furthermore, the multi-threaded countermeasure is unaffected by the elastic alignment and filtering techniques as opposed to the existing countermeasures. The research concludes that the multithreaded coun-termeasure is indeed a secure implementation to mitigate SCA attacks.
- Full Text:
- Date Issued: 2016
- Authors: Frieslaar, Ibrahim , Irwin, Barry V W
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428352 , vital:72505 , https://researchspace.csir.co.za/dspace/bitstream/handle/10204/9041/Frieslaar_2016.pdf?sequence=1andisAllowed=y
- Description: This research investigates the resistance of the multi-threaded coun-termeasure to side channel analysis (SCA) attacks. The multi-threaded countermeasure is attacked using the Correlation Power Analysis (CPA) and template attacks. Additionally, it is compared to the existing hiding countermeasure. Furthermore, additional signal processing techniques are used to increase the attack success ratio. It is demon-strated that the multi-threaded countermeasure is able to outperform the existing countermeasures by withstanding the CPA and template at-tacks. Furthermore, the multi-threaded countermeasure is unaffected by the elastic alignment and filtering techniques as opposed to the existing countermeasures. The research concludes that the multithreaded coun-termeasure is indeed a secure implementation to mitigate SCA attacks.
- Full Text:
- Date Issued: 2016
Parallel visions: Byron, Géricault and the Medusa
- Authors: Beard, Margot
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147792 , vital:38673 , https://doi.org/10.1080/00043389.1999.11761285
- Description: Martin Meisel has noted that Delacroix's 1841 painting A Shipwreck was recognised as uniting Gericault and Byron. for not only does the painting illustrate that moment in Don Juan when lots are drawn for the human sacrifice {2, 75) but it also invokes comparison with Gericault' s 1819 painting entitled Raft of the Medusa(Meisel1988:601).1 would like to argue in this paper that Gericault' s famous painting and Byron's shipwreck stanzas in the second canto of Don Juan have other points of comparison. Gericault used the Savigny and Correard Narrative of a Voyage to Senegal ( 1817) as the primary source of information for his treatment of the Medusa incident (Eitner 1971: 117). Byron used multiple sources when he researched material for his shipwreck stanzas but it is highly probable that the Savigny and Correard text was one of them. Thus, the cause celebre of the wreck of the Medusa is directly treated by Gericault and indirectly by Byron - two artists temperamentally and artistically attuned.
- Full Text:
- Date Issued: 2016
- Authors: Beard, Margot
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147792 , vital:38673 , https://doi.org/10.1080/00043389.1999.11761285
- Description: Martin Meisel has noted that Delacroix's 1841 painting A Shipwreck was recognised as uniting Gericault and Byron. for not only does the painting illustrate that moment in Don Juan when lots are drawn for the human sacrifice {2, 75) but it also invokes comparison with Gericault' s 1819 painting entitled Raft of the Medusa(Meisel1988:601).1 would like to argue in this paper that Gericault' s famous painting and Byron's shipwreck stanzas in the second canto of Don Juan have other points of comparison. Gericault used the Savigny and Correard Narrative of a Voyage to Senegal ( 1817) as the primary source of information for his treatment of the Medusa incident (Eitner 1971: 117). Byron used multiple sources when he researched material for his shipwreck stanzas but it is highly probable that the Savigny and Correard text was one of them. Thus, the cause celebre of the wreck of the Medusa is directly treated by Gericault and indirectly by Byron - two artists temperamentally and artistically attuned.
- Full Text:
- Date Issued: 2016
Principles of Control Protocol Design and Implementation
- Eales, Andrew, Foss, Richard
- Authors: Eales, Andrew , Foss, Richard
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426801 , vital:72392 , https://www.aes.org/e-lib/online/browse.cfm?elib=18238
- Description: Control protocols are used within audio networks to manage both audio streams and networked audio devices. A number of control protocols for audio devices have been recently developed, including the AES standards AES64-2012 and AES70-2015. Despite these developments, an ontology of control protocol design and implementation does not exist. This paper proposes design and implementation heuristics for control protocols. Different categories of control protocol design and implementation heuristics are presented and the implications of individual heuristics are discussed. These heuristics allow the features provided by different control protocols to be compared and evaluated and provide guidelines for future control protocol development.
- Full Text:
- Date Issued: 2016
- Authors: Eales, Andrew , Foss, Richard
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426801 , vital:72392 , https://www.aes.org/e-lib/online/browse.cfm?elib=18238
- Description: Control protocols are used within audio networks to manage both audio streams and networked audio devices. A number of control protocols for audio devices have been recently developed, including the AES standards AES64-2012 and AES70-2015. Despite these developments, an ontology of control protocol design and implementation does not exist. This paper proposes design and implementation heuristics for control protocols. Different categories of control protocol design and implementation heuristics are presented and the implications of individual heuristics are discussed. These heuristics allow the features provided by different control protocols to be compared and evaluated and provide guidelines for future control protocol development.
- Full Text:
- Date Issued: 2016
Quantitative analysis of time-resolved infrared stimulated luminescence in feldspars
- Pagonis, Vasilis, Ankjærgaard, Christina, Jain, Mayank, Chithambo, Makaiko L
- Authors: Pagonis, Vasilis , Ankjærgaard, Christina , Jain, Mayank , Chithambo, Makaiko L
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124616 , vital:35638 , DOI: 10.1016/j.physb.2016.06.013
- Description: Time-resolved infrared-stimulated luminescence (TR-IRSL) from feldspar samples is of importance in the field of luminescence dating, since it provides information on the luminescence mechanism in these materials. In this paper we present new analytical equations which can be used to analyze TR-IRSL signals, both during and after short infrared stimulation pulses. The equations are developed using a recently proposed kinetic model, which describes localized electronic recombination via tunneling between trapped electrons and recombination centers in luminescent materials. Recombination is assumed to take place from the excited state of the trapped electron to the nearest-neighbor center within a random distribution of luminescence recombination centers. Different possibilities are examined within the model, depending on the relative importance of electron de-excitation and recombination. The equations are applied to experimental TR-IRSL data of natural feldspars, and good agreement is found between experimental and modeling results.
- Full Text:
- Date Issued: 2016
- Authors: Pagonis, Vasilis , Ankjærgaard, Christina , Jain, Mayank , Chithambo, Makaiko L
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124616 , vital:35638 , DOI: 10.1016/j.physb.2016.06.013
- Description: Time-resolved infrared-stimulated luminescence (TR-IRSL) from feldspar samples is of importance in the field of luminescence dating, since it provides information on the luminescence mechanism in these materials. In this paper we present new analytical equations which can be used to analyze TR-IRSL signals, both during and after short infrared stimulation pulses. The equations are developed using a recently proposed kinetic model, which describes localized electronic recombination via tunneling between trapped electrons and recombination centers in luminescent materials. Recombination is assumed to take place from the excited state of the trapped electron to the nearest-neighbor center within a random distribution of luminescence recombination centers. Different possibilities are examined within the model, depending on the relative importance of electron de-excitation and recombination. The equations are applied to experimental TR-IRSL data of natural feldspars, and good agreement is found between experimental and modeling results.
- Full Text:
- Date Issued: 2016
The network society: A model for computing infrastructure in South African schools
- Siebörger, Ingrid, Terzoli, Alfredo
- Authors: Siebörger, Ingrid , Terzoli, Alfredo
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430651 , vital:72706 , 10.1109/ISTAFRICA.2016.7530673
- Description: Worldwide computers are being used in schools for, amongst other things, developing the knowledge and skills required for citizens to be able to operate within the 21st Century Information Age. Realising the potential of technology in uplifting the lives of its citizens the South Afri-can government has proposed the National Broadband Plan (SA Con-nect). However, unfortunately this plan only addresses the networking aspect of Information Communication Technologies (ICTs). In this pa-per we investigate appropriate Information Technologies for schools in the light of SA Connect, and propose a model for the computing infra-structure required in South African schools in order to support access to and adoption of technology and networks. This model is based on our multi-year experimentation in the Siyakhula Living Lab.
- Full Text:
- Date Issued: 2016
- Authors: Siebörger, Ingrid , Terzoli, Alfredo
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430651 , vital:72706 , 10.1109/ISTAFRICA.2016.7530673
- Description: Worldwide computers are being used in schools for, amongst other things, developing the knowledge and skills required for citizens to be able to operate within the 21st Century Information Age. Realising the potential of technology in uplifting the lives of its citizens the South Afri-can government has proposed the National Broadband Plan (SA Con-nect). However, unfortunately this plan only addresses the networking aspect of Information Communication Technologies (ICTs). In this pa-per we investigate appropriate Information Technologies for schools in the light of SA Connect, and propose a model for the computing infra-structure required in South African schools in order to support access to and adoption of technology and networks. This model is based on our multi-year experimentation in the Siyakhula Living Lab.
- Full Text:
- Date Issued: 2016
The pattern-richness of graphical passwords
- Vorster, Johannes, Van Heerden, Renier, Irwin, Barry V W
- Authors: Vorster, Johannes , Van Heerden, Renier , Irwin, Barry V W
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68322 , vital:29238 , https://doi.org/10.1109/ISSA.2016.7802931
- Description: Publisher version , Conventional (text-based) passwords have shown patterns such as variations on the username, or known passwords such as “password”, “admin” or “12345”. Patterns may similarly be detected in the use of Graphical passwords (GPs). The most significant such pattern - reported by many researchers - is hotspot clustering. This paper qualitatively analyses more than 200 graphical passwords for patterns other than the classically reported hotspots. The qualitative analysis finds that a significant percentage of passwords fall into a small set of patterns; patterns that can be used to form attack models against GPs. In counter action, these patterns can also be used to educate users so that future password selection is more secure. It is the hope that the outcome from this research will lead to improved behaviour and an enhancement in graphical password security.
- Full Text: false
- Date Issued: 2016
- Authors: Vorster, Johannes , Van Heerden, Renier , Irwin, Barry V W
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68322 , vital:29238 , https://doi.org/10.1109/ISSA.2016.7802931
- Description: Publisher version , Conventional (text-based) passwords have shown patterns such as variations on the username, or known passwords such as “password”, “admin” or “12345”. Patterns may similarly be detected in the use of Graphical passwords (GPs). The most significant such pattern - reported by many researchers - is hotspot clustering. This paper qualitatively analyses more than 200 graphical passwords for patterns other than the classically reported hotspots. The qualitative analysis finds that a significant percentage of passwords fall into a small set of patterns; patterns that can be used to form attack models against GPs. In counter action, these patterns can also be used to educate users so that future password selection is more secure. It is the hope that the outcome from this research will lead to improved behaviour and an enhancement in graphical password security.
- Full Text: false
- Date Issued: 2016
Thermoluminescence of kunzite: a study of kinetic processes and dosimetry characteristics
- Ogundare, F O, Alatishe, M A, Chithambo, Makaiko L, Costin, G
- Authors: Ogundare, F O , Alatishe, M A , Chithambo, Makaiko L , Costin, G
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124701 , vital:35650 , https://doi.org/10.1016/j.nimb.2016.02.059
- Description: Since the use of natural minerals for dating and dose reconstruction using luminescence techniques is well-established and always of interest, we present thermoluminescence characteristics of kunzite, a gem variety of spodumene. The chemical composition of the sample was determined using an Electron Probe MicroAnalyzer.
- Full Text: false
- Date Issued: 2016
- Authors: Ogundare, F O , Alatishe, M A , Chithambo, Makaiko L , Costin, G
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124701 , vital:35650 , https://doi.org/10.1016/j.nimb.2016.02.059
- Description: Since the use of natural minerals for dating and dose reconstruction using luminescence techniques is well-established and always of interest, we present thermoluminescence characteristics of kunzite, a gem variety of spodumene. The chemical composition of the sample was determined using an Electron Probe MicroAnalyzer.
- Full Text: false
- Date Issued: 2016
A Connection Management System to Enable the Wireless Transmission of MIDI Messages
- Authors: Shaw, Brent , Foss, Richard
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426829 , vital:72394 , https://www.aes.org/e-lib/browse.cfm?elib=18030
- Description: This paper examines the design and implementation of a wireless system for the distribution of MIDI messages for show control and studio environments. The system makes use of the MIDI and MIDINet protocols, creating wireless nodes that will enable the transmission of MIDI between devices on a wireless network with connection management capabilities through the use of embedded web servers. The paper describes the current state of the art, configuration of the system, hardware architectures, software design, and implementation.
- Full Text:
- Date Issued: 2015
- Authors: Shaw, Brent , Foss, Richard
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426829 , vital:72394 , https://www.aes.org/e-lib/browse.cfm?elib=18030
- Description: This paper examines the design and implementation of a wireless system for the distribution of MIDI messages for show control and studio environments. The system makes use of the MIDI and MIDINet protocols, creating wireless nodes that will enable the transmission of MIDI between devices on a wireless network with connection management capabilities through the use of embedded web servers. The paper describes the current state of the art, configuration of the system, hardware architectures, software design, and implementation.
- Full Text:
- Date Issued: 2015
A description of gametogenesis in the panga Pterogymnus laniarius (Pisces: Sparidae) with comments on changes in maturity patterns over the past two decades
- Booth, Anthony J, Hecht, Thomas
- Authors: Booth, Anthony J , Hecht, Thomas
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123542 , vital:35452 , https://doi.org/10.1080/02541858.1997.11448428
- Description: A description of gametogenesis in the panga Pferogymnus laniarius, a common endemic seabream species inhabiting the Agulhas Bank, South Africa, is presented. After sexual maturity, oogenesis and spermatogenesis continued throughout the year and were found to be similar to these processes in other seabream species and teleosts in general. Analysis of maturity data over the past two decades revealed a significant change in both age and size-at-maturity, a response to fishing pressure.
- Full Text:
- Date Issued: 2015
- Authors: Booth, Anthony J , Hecht, Thomas
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123542 , vital:35452 , https://doi.org/10.1080/02541858.1997.11448428
- Description: A description of gametogenesis in the panga Pferogymnus laniarius, a common endemic seabream species inhabiting the Agulhas Bank, South Africa, is presented. After sexual maturity, oogenesis and spermatogenesis continued throughout the year and were found to be similar to these processes in other seabream species and teleosts in general. Analysis of maturity data over the past two decades revealed a significant change in both age and size-at-maturity, a response to fishing pressure.
- Full Text:
- Date Issued: 2015
An exploration of the principle of Dance Movement Therapy in water resource management research practice:
- Authors: Copteros, Athina
- Date: 2015
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/142016 , vital:38024 , ISBN PECS Conference: Social-ecological dynamics in the Anthropocene, Spier Estate, Cape Town, 2-5 November , http://www.pecs-science.org/research/news/news/2015pecsconferencesocialecologicaldynamicsintheanthropocene.5.40768cbb14b32a0480b694.html
- Description: An exploration of the principle of Dance Movement Therapy in water resource management research practice
- Full Text:
- Date Issued: 2015
- Authors: Copteros, Athina
- Date: 2015
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/142016 , vital:38024 , ISBN PECS Conference: Social-ecological dynamics in the Anthropocene, Spier Estate, Cape Town, 2-5 November , http://www.pecs-science.org/research/news/news/2015pecsconferencesocialecologicaldynamicsintheanthropocene.5.40768cbb14b32a0480b694.html
- Description: An exploration of the principle of Dance Movement Therapy in water resource management research practice
- Full Text:
- Date Issued: 2015
DDoS Attack Mitigation Through Control of Inherent Charge Decay of Memory Implementations
- Herbert, Alan, Irwin, Barry V W, van Heerden, Renier P
- Authors: Herbert, Alan , Irwin, Barry V W , van Heerden, Renier P
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430339 , vital:72684 , https://www.academic-bookshop.com/ourshop/prod_3774091-ICCWS-2015-10th-International-Conference-on-Cyber-Warfare-and-Security-Kruger-National-Park-South-Africa-PRINT-ver-ISBN-978191030996.html
- Description: DDoS (Distributed Denial of Service) attacks over recent years have shown to be devastating on the target systems and services made publicly available over the Internet. Furthermore, the backscatter1 caused by DDoS attacks also affects the available bandwidth and responsiveness of many other hosts within the Internet. The unfortunate reality of these attacks is that the targeted party cannot fight back due to the presence of botnets and malware-driven hosts. These hosts that carry out the attack on a target are usually controlled remotely and the owner of the device is unaware of it; for this reason one cannot attack back directly as this will serve little more than to disable an innocent party. A proposed solution to these DDoS attacks is to identify a potential attacking address and ignore communication from that address for a set period of time through time stamping.
- Full Text:
- Date Issued: 2015
- Authors: Herbert, Alan , Irwin, Barry V W , van Heerden, Renier P
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430339 , vital:72684 , https://www.academic-bookshop.com/ourshop/prod_3774091-ICCWS-2015-10th-International-Conference-on-Cyber-Warfare-and-Security-Kruger-National-Park-South-Africa-PRINT-ver-ISBN-978191030996.html
- Description: DDoS (Distributed Denial of Service) attacks over recent years have shown to be devastating on the target systems and services made publicly available over the Internet. Furthermore, the backscatter1 caused by DDoS attacks also affects the available bandwidth and responsiveness of many other hosts within the Internet. The unfortunate reality of these attacks is that the targeted party cannot fight back due to the presence of botnets and malware-driven hosts. These hosts that carry out the attack on a target are usually controlled remotely and the owner of the device is unaware of it; for this reason one cannot attack back directly as this will serve little more than to disable an innocent party. A proposed solution to these DDoS attacks is to identify a potential attacking address and ignore communication from that address for a set period of time through time stamping.
- Full Text:
- Date Issued: 2015
Employing safe bets: reflections on attracting, developing and retaining the next generation of academics
- Authors: Hlengwa, Amanda I
- Date: 2015
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/142145 , vital:38053 , ISBN 9781869142902 , https://books.google.co.za/books?id=49o8rgEACAAJanddq=Being+at+home:+Race,+institutional+culture+and+transformation+at+South+African+higher+education+institutionandhl=enandsa=Xandved=0ahUKEwiPgsa6mpjjAhXNN8AKHbNwAtoQ6AEIKDAA
- Description: This edited work has gathered together contributions on how to transform universities in South Africa; as many are struggling to shift their institutional culture. In a South African context, transformation means to attempt to change higher education institutions such that they no longer reflect the values promoted by apartheid but rather reflect the values embodied in South Africa's 1996 Constitution. Institutional culture is the main subject for discussion in this book. In order to transform South Africa's universities, the contributors begin by analyzing the idea of what a university is, and relatedly, what its ideal aims are. A second theme is to understand what institutional culture is and how it functions. Moreover, transformation cannot occur without transforming the broader cultures of which they are a part. Related to this theme is a general concern about how contemporary moves towards the instrumentalization of higher education affect the ability to transform institutions. These institutions are being pushed to conform to goals that are outside the traditional idea of a university, such as concerns that universities are being 'bureaucratized' and becoming corporations, instead of a place of learning open to all. In conclusion it can be said that the contemporary South African academic community has an opportunity to recreate itself as the end of apartheid created space for engaging in transformative epistemic projects. The transformation of the tertiary sector entails a transformation of institutional cultures.
- Full Text:
- Date Issued: 2015
- Authors: Hlengwa, Amanda I
- Date: 2015
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/142145 , vital:38053 , ISBN 9781869142902 , https://books.google.co.za/books?id=49o8rgEACAAJanddq=Being+at+home:+Race,+institutional+culture+and+transformation+at+South+African+higher+education+institutionandhl=enandsa=Xandved=0ahUKEwiPgsa6mpjjAhXNN8AKHbNwAtoQ6AEIKDAA
- Description: This edited work has gathered together contributions on how to transform universities in South Africa; as many are struggling to shift their institutional culture. In a South African context, transformation means to attempt to change higher education institutions such that they no longer reflect the values promoted by apartheid but rather reflect the values embodied in South Africa's 1996 Constitution. Institutional culture is the main subject for discussion in this book. In order to transform South Africa's universities, the contributors begin by analyzing the idea of what a university is, and relatedly, what its ideal aims are. A second theme is to understand what institutional culture is and how it functions. Moreover, transformation cannot occur without transforming the broader cultures of which they are a part. Related to this theme is a general concern about how contemporary moves towards the instrumentalization of higher education affect the ability to transform institutions. These institutions are being pushed to conform to goals that are outside the traditional idea of a university, such as concerns that universities are being 'bureaucratized' and becoming corporations, instead of a place of learning open to all. In conclusion it can be said that the contemporary South African academic community has an opportunity to recreate itself as the end of apartheid created space for engaging in transformative epistemic projects. The transformation of the tertiary sector entails a transformation of institutional cultures.
- Full Text:
- Date Issued: 2015
Immersive audio content creation using mobile devices and ethernet avb
- Rouget, Antoine, Foss, Richard
- Authors: Rouget, Antoine , Foss, Richard
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426786 , vital:72391 , https://www.aes.org/e-lib/browse.cfm?elib=18009
- Description: The goal of immersive sound systems is to localize multiple sound sources such that listeners are enveloped in sound. This paper describes an immersive sound system that allows for the creation of immersive sound content and real time control over sound source localization. It is a client/server system where the client is a mobile device. The server receives localization control messages from the client and uses an Ethernet AVB network to distribute appropriate mix levels to speakers with in-built signal processing.
- Full Text:
- Date Issued: 2015
- Authors: Rouget, Antoine , Foss, Richard
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426786 , vital:72391 , https://www.aes.org/e-lib/browse.cfm?elib=18009
- Description: The goal of immersive sound systems is to localize multiple sound sources such that listeners are enveloped in sound. This paper describes an immersive sound system that allows for the creation of immersive sound content and real time control over sound source localization. It is a client/server system where the client is a mobile device. The server receives localization control messages from the client and uses an Ethernet AVB network to distribute appropriate mix levels to speakers with in-built signal processing.
- Full Text:
- Date Issued: 2015
Incipient genetic isolation of a temperate migratory coastal sciaenid fish (Argyrosomus inodorus) within the Benguela Cold Current system
- Henriques, Romina, Potts, Warren M, Sauer, Warwick H H, Shaw, Paul W
- Authors: Henriques, Romina , Potts, Warren M , Sauer, Warwick H H , Shaw, Paul W
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124710 , vital:35652 , https://doi.10.1080/17451000.2014.952309
- Description: The Benguela Cold Current system, located in the south-eastern Atlantic, features cold sea surface temperatures, bounded to the north and south by tropical currents (the Angola and Agulhas Currents, respectively) and a perennial upwelling cell off central Namibia that divides the region into two sub-systems with different characteristics (Shannon 1985; Hutchings et al. 2009). The colder sea surface temperatures of the Benguela Current have been considered an important biogeographic barrier, isolating tropical and warm-temperate fauna of the Atlantic and Indo-Pacific Oceans (Avise 2000; Floeter et al. 2008). However, recent studies revealed that other oceanographic features, such as the perennial upwelling cell, may also play an important role in shaping the population structure of warm temperate fish populations within the Benguela system, as complete disruption of gene flow was documented both in Lichia amia (Linnaeus, 1758) and Atractoscion aequidens (Cuvier, 1830) (Henriques et al. 2012, 2014). Little is known, however, regarding the influence of the Benguela system on genetic population connectivity of cold-water-tolerant species.
- Full Text:
- Date Issued: 2015
- Authors: Henriques, Romina , Potts, Warren M , Sauer, Warwick H H , Shaw, Paul W
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124710 , vital:35652 , https://doi.10.1080/17451000.2014.952309
- Description: The Benguela Cold Current system, located in the south-eastern Atlantic, features cold sea surface temperatures, bounded to the north and south by tropical currents (the Angola and Agulhas Currents, respectively) and a perennial upwelling cell off central Namibia that divides the region into two sub-systems with different characteristics (Shannon 1985; Hutchings et al. 2009). The colder sea surface temperatures of the Benguela Current have been considered an important biogeographic barrier, isolating tropical and warm-temperate fauna of the Atlantic and Indo-Pacific Oceans (Avise 2000; Floeter et al. 2008). However, recent studies revealed that other oceanographic features, such as the perennial upwelling cell, may also play an important role in shaping the population structure of warm temperate fish populations within the Benguela system, as complete disruption of gene flow was documented both in Lichia amia (Linnaeus, 1758) and Atractoscion aequidens (Cuvier, 1830) (Henriques et al. 2012, 2014). Little is known, however, regarding the influence of the Benguela system on genetic population connectivity of cold-water-tolerant species.
- Full Text:
- Date Issued: 2015
Introduction: the need to understand the ecological sustainability of non-timber forest products harvesting systems
- Shackleton, Charlie M, Ticktin, Tamara, Pandey, Ashok K
- Authors: Shackleton, Charlie M , Ticktin, Tamara , Pandey, Ashok K
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433683 , vital:72994 , ISBN 9781317916130 , https://www.taylorfrancis.com/chapters/edit/10.4324/9781315851587-2/introduction-charlie-shackleton-tamara-ticktin-ashok-pandey
- Description: The importance of non-timber forest products (NTFPs) in rural livelihoods in developing countries has become widely acknowledged over the last decade or so within the research and, increasingly, policy arenas, on the basis of numerous studies from around the world. Indeed, there has been a tenfold increase in the annual number of research papers published over the last 20 years (Figure 1.1). Most of these studies are from developing countries, but they do include developed countries (e.g. Kim et al. 2012, Poe et al. 2013, Sténs and Sandström 2013). Additionally, most are from rural areas, albeit with a smattering from urban settings (e.g. Kilchling et al. 2009, Poe et al. 2013, Kaoma and Shackleton 2014), although with increasing urbanization this distinction is blurred with significant markets for rural NTFPs imported into towns and cities (Lewis 2008, Padoch et al. 2008, McMullin et al. 2012). Two pertinent findings of many of these studies is that NTFPs generally contribute in many different ways to local livelihoods (see Chapter 2) and that when translated into income terms many households earn a significant proportion of their income (cash and/or non-cash) from NTFPs (Shackleton et al. 2007, Angelsen et al. 2014). In other words, they are not simply minor products of little value, but rather they are vital components of livelihoods, and in some instances, of local and regional economies. This requires that they, and the land on which they are found, are managed in a responsible manner to ensure that these livelihood benefits continue to accrue to rural, and often impoverished, people.
- Full Text:
- Date Issued: 2015
- Authors: Shackleton, Charlie M , Ticktin, Tamara , Pandey, Ashok K
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433683 , vital:72994 , ISBN 9781317916130 , https://www.taylorfrancis.com/chapters/edit/10.4324/9781315851587-2/introduction-charlie-shackleton-tamara-ticktin-ashok-pandey
- Description: The importance of non-timber forest products (NTFPs) in rural livelihoods in developing countries has become widely acknowledged over the last decade or so within the research and, increasingly, policy arenas, on the basis of numerous studies from around the world. Indeed, there has been a tenfold increase in the annual number of research papers published over the last 20 years (Figure 1.1). Most of these studies are from developing countries, but they do include developed countries (e.g. Kim et al. 2012, Poe et al. 2013, Sténs and Sandström 2013). Additionally, most are from rural areas, albeit with a smattering from urban settings (e.g. Kilchling et al. 2009, Poe et al. 2013, Kaoma and Shackleton 2014), although with increasing urbanization this distinction is blurred with significant markets for rural NTFPs imported into towns and cities (Lewis 2008, Padoch et al. 2008, McMullin et al. 2012). Two pertinent findings of many of these studies is that NTFPs generally contribute in many different ways to local livelihoods (see Chapter 2) and that when translated into income terms many households earn a significant proportion of their income (cash and/or non-cash) from NTFPs (Shackleton et al. 2007, Angelsen et al. 2014). In other words, they are not simply minor products of little value, but rather they are vital components of livelihoods, and in some instances, of local and regional economies. This requires that they, and the land on which they are found, are managed in a responsible manner to ensure that these livelihood benefits continue to accrue to rural, and often impoverished, people.
- Full Text:
- Date Issued: 2015
Multi sensor national cyber security data fusion
- Swart, Ignus, Irwin, Barry V W, Grobler, Marthie
- Authors: Swart, Ignus , Irwin, Barry V W , Grobler, Marthie
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430393 , vital:72688 , https://www.academic-bookshop.com/ourshop/prod_3774091-ICCWS-2015-10th-International-Conference-on-Cyber-Warfare-and-Security-Kruger-National-Park-South-Africa-PRINT-ver-ISBN-978191030996.html
- Description: A proliferation of cyber security strategies have recently been published around the world with as many as thirty five strategies documented since 2009. These published strategies indicate the growing need to obtain a clear view of a country’s information security posture and to improve on it. The potential attack surface of a nation is extremely large however and no single source of cyber security data provides all the required information to accurately describe the cyber security readiness of a nation. There are however a variety of specialised data sources that are rich enough in relevant cyber security information to assess the state of a nation in at least key areas such as botnets, spam servers and incorrectly configured hosts present in a country. While informative both from an offensive and defensive point of view, the data sources range in a variety of factors such as accuracy, completeness, representation, cost and data availability. These factors add complexity when attempting to present a clear view of the combined intelligence of the data.
- Full Text:
- Date Issued: 2015
- Authors: Swart, Ignus , Irwin, Barry V W , Grobler, Marthie
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430393 , vital:72688 , https://www.academic-bookshop.com/ourshop/prod_3774091-ICCWS-2015-10th-International-Conference-on-Cyber-Warfare-and-Security-Kruger-National-Park-South-Africa-PRINT-ver-ISBN-978191030996.html
- Description: A proliferation of cyber security strategies have recently been published around the world with as many as thirty five strategies documented since 2009. These published strategies indicate the growing need to obtain a clear view of a country’s information security posture and to improve on it. The potential attack surface of a nation is extremely large however and no single source of cyber security data provides all the required information to accurately describe the cyber security readiness of a nation. There are however a variety of specialised data sources that are rich enough in relevant cyber security information to assess the state of a nation in at least key areas such as botnets, spam servers and incorrectly configured hosts present in a country. While informative both from an offensive and defensive point of view, the data sources range in a variety of factors such as accuracy, completeness, representation, cost and data availability. These factors add complexity when attempting to present a clear view of the combined intelligence of the data.
- Full Text:
- Date Issued: 2015
Observed correlations of unsolicited network traffic over five distinct IPv4 netblocks
- Nkhumeleni, Thiswilondi M, Irwin, Barry V W
- Authors: Nkhumeleni, Thiswilondi M , Irwin, Barry V W
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430408 , vital:72689 , https://www.academic-bookshop.com/ourshop/prod_3774091-ICCWS-2015-10th-International-Conference-on-Cyber-Warfare-and-Security-Kruger-National-Park-South-Africa-PRINT-ver-ISBN-978191030996.html
- Description: Using network telescopes to monitor unused IP address space provides a favorable environment for researchers to study and detect malware, denial of service and scanning activities within global IPv4 address space. This research focuses on comparative and correlation analysis of traffic activity across the network of telescope sensors. Analysis is done using data collected over a 12 month period on five network telescopes each with an aperture size of/24, operated in disjoint IPv4 address space. These were considered as two distinct groupings. Time series’ representing time-based traffic activity observed on these sensors was constructed. Using the cross-and auto-correlation methods of time series analysis, moderate correlation of traffic activity was achieved between telescope sensors in each category. Weak to moderate correlation was calculated when comparing category A and category B network telescopes’ datasets. Results were significantly improved by considering TCP traffic separately. Moderate to strong correlation coefficients in each category were calculated when using TCP traffic only. UDP traffic analysis showed weaker correlation between sensors, however the uniformity of ICMP traffic showed correlation of traffic activity across all sensors. The results confirmed the visual observation of traffic relativity in telescope sensors within the same category and quantitatively analyzed the correlation of network telescopes’ traffic activity.
- Full Text:
- Date Issued: 2015
- Authors: Nkhumeleni, Thiswilondi M , Irwin, Barry V W
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430408 , vital:72689 , https://www.academic-bookshop.com/ourshop/prod_3774091-ICCWS-2015-10th-International-Conference-on-Cyber-Warfare-and-Security-Kruger-National-Park-South-Africa-PRINT-ver-ISBN-978191030996.html
- Description: Using network telescopes to monitor unused IP address space provides a favorable environment for researchers to study and detect malware, denial of service and scanning activities within global IPv4 address space. This research focuses on comparative and correlation analysis of traffic activity across the network of telescope sensors. Analysis is done using data collected over a 12 month period on five network telescopes each with an aperture size of/24, operated in disjoint IPv4 address space. These were considered as two distinct groupings. Time series’ representing time-based traffic activity observed on these sensors was constructed. Using the cross-and auto-correlation methods of time series analysis, moderate correlation of traffic activity was achieved between telescope sensors in each category. Weak to moderate correlation was calculated when comparing category A and category B network telescopes’ datasets. Results were significantly improved by considering TCP traffic separately. Moderate to strong correlation coefficients in each category were calculated when using TCP traffic only. UDP traffic analysis showed weaker correlation between sensors, however the uniformity of ICMP traffic showed correlation of traffic activity across all sensors. The results confirmed the visual observation of traffic relativity in telescope sensors within the same category and quantitatively analyzed the correlation of network telescopes’ traffic activity.
- Full Text:
- Date Issued: 2015
Photodynamic antimicrobial chemotherapy activity of (5,10,15,20-tetrakis(4-(4-carboxyphenycarbonoimidoyl)phenyl)porphyrinato) chloro gallium(III)
- Managa, Muthumuni, Amuhaya, Edith, Nyokong, Tebello
- Authors: Managa, Muthumuni , Amuhaya, Edith , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7296 , http://hdl.handle.net/10962/d1020359
- Description: (5,10,15,20-Tetrakis(4-(4-carboxyphenycarbonoimidoyl)phenyl)porphyrinato) chloro gallium(III) (complex 1) was conjugated to platinum nanoparticles (PtNPs) (represented as 1-PtNPs). The resulting conjugate showed 18 nm red shift in the Soret band when compared to 1 alone. Complex 1 and 1-PtNPs showed promising photodynamic antimicrobial chemotherapy (PACT) activity against Staphylococcus aureus, Escherichia coli and Candida albicans in solution where the log reductions obtained were 4.92, 3.76, and 3.95, respectively for 1-PtNPs. The singlet oxygen quantum yields obtained were higher at 0.56 for 1-PtNPs in DMF while that of 1 was 0.52 in the same solvent. This resulted in improved PACT activity for 1-PtNPs compared to 1 alone. , Original publication is available at http://dx.doi.org/10.1016/j.saa.2015.06.088
- Full Text: false
- Date Issued: 2015
- Authors: Managa, Muthumuni , Amuhaya, Edith , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7296 , http://hdl.handle.net/10962/d1020359
- Description: (5,10,15,20-Tetrakis(4-(4-carboxyphenycarbonoimidoyl)phenyl)porphyrinato) chloro gallium(III) (complex 1) was conjugated to platinum nanoparticles (PtNPs) (represented as 1-PtNPs). The resulting conjugate showed 18 nm red shift in the Soret band when compared to 1 alone. Complex 1 and 1-PtNPs showed promising photodynamic antimicrobial chemotherapy (PACT) activity against Staphylococcus aureus, Escherichia coli and Candida albicans in solution where the log reductions obtained were 4.92, 3.76, and 3.95, respectively for 1-PtNPs. The singlet oxygen quantum yields obtained were higher at 0.56 for 1-PtNPs in DMF while that of 1 was 0.52 in the same solvent. This resulted in improved PACT activity for 1-PtNPs compared to 1 alone. , Original publication is available at http://dx.doi.org/10.1016/j.saa.2015.06.088
- Full Text: false
- Date Issued: 2015