Visualisation of PF firewall logs using open source
- Authors: Coetzee, Dirk
- Date: 2015
- Subjects: Open source software -- South Africa , Firewalls (Computer security) -- South Africa , Data logging -- South Africa , Data integrity -- South Africa , Data protection -- South Africa , Computer crimes -- South Africa , Hacktivism
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4719 , http://hdl.handle.net/10962/d1018552
- Description: If you cannot measure, you cannot manage. This is an age old saying, but still very true, especially within the current South African cybercrime scene and the ever-growing Internet footprint. Due to the significant increase in cybercrime across the globe, information security specialists are starting to see the intrinsic value of logs that can ‘tell a story’. Logs do not only tell a story, but also provide a tool to measure a normally dark force within an organisation. The collection of current logs from installed systems, operating systems and devices is imperative in the event of a hacking attempt, data leak or even data theft, whether the attempt is successful or unsuccessful. No logs mean no evidence, and in many cases not even the opportunity to find the mistake or fault in the organisation’s defence systems. Historically, it remains difficult to choose what logs are required by your organization. A number of questions should be considered: should a centralised or decentralised approach for collecting these logs be followed or a combination of both? How many events will be collected, how much additional bandwidth will be required and will the log collection be near real time? How long must the logs be saved and what if any hashing and encryption (integrity of data) should be used? Lastly, what system must be used to correlate, analyse, and make alerts and reports available? This thesis will address these myriad questions, examining the current lack of log analysis, practical implementations in modern organisation, and also how a need for the latter can be fulfilled by means of a basic approach. South African organizations must use technology that is at hand in order to know what electronic data are sent in and out of their organizations network. Concentrating only on FreeBSD PF firewall logs, it is demonstrated within this thesis the excellent results are possible when logs are collected to obtain a visual display of what data is traversing the corporate network and which parts of this data are posing a threat to the corporate network. This threat is easily determined via a visual interpretation of statistical outliers. This thesis aims to show that in the field of corporate data protection, if you can measure, you can manage.
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- Date Issued: 2015
A study of spherical solutions in chameleon scalar-tensor theories
- Authors: Mohapi, Neo
- Date: 2014
- Subjects: Scalar field theory , Equivalence principle (Physics) , General relativity (Physics) , Bosons , Dark energy (Astronomy) , Galactic dynamics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5428 , http://hdl.handle.net/10962/d1013315
- Description: The equivalence principle has proven to be central to theories of gravity, with General Relativity being the simplest and most elegant theory to embody the principle. Most alternative theories of gravity struggle to satisfy the principle and still be distinct from GR. Extensions of cosmological and quantum theories question the irrefutably of the equivalence at every scale. The possibility of an equivalence principle violation at galactic scales would be an exciting prospect. In this thesis, we will carefully examine the equivalence principle through the study of chameleon scalar-tensor theories, this will include solutions for hypothetical stars known as boson stars. Such theories find varied application, especially in cosmology, where they model dark energy and inflation. The AWE hypothesis, is an instance of this. It is a nonuniversally coupled model in which violations of the equivalence principle on galactic scales may be apparent. We investigate spherically symmetric and static solutions within the framework of this theory. The constraints obtained from galactic rotation curves results in values of the couplings that show no significant violation of the equivalence principle or values consistent with a theory of dark energy
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- Date Issued: 2014
In silico characterisation of the four canonical plasmodium falciparum 70 kDa heat shock proteins
- Authors: Hatherley, Rowan
- Date: 2012
- Subjects: Heat shock proteins -- Research , Plasmodium falciparum -- Research , Plasmodium -- Research , Endoplasmic reticulum , Cytosol , Mitochondria -- Formation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4026 , http://hdl.handle.net/10962/d1004086 , Heat shock proteins -- Research , Plasmodium falciparum -- Research , Plasmodium -- Research , Endoplasmic reticulum , Cytosol , Mitochondria -- Formation
- Description: The 70 kDa heat shock proteins expressed by Plasmodium falciparum (PfHsp70s) are believed to be essential to both the survival and virulence of the malaria parasite. A total of six Hsp70 genes have been identified in the genome of P. falciparum. However, only four of these encode canonical Hsp70s, which are believed to localise predominantly in the cytosol (PfHsp70-1 and PfHsp70-x), the endoplasmic reticulum (PfHsp70-2) and mitochondria (PfHsp70-3) of the parasite. These proteins bind and release peptide substrates in an ATP-dependent manner, with the aid of a J-domain protein cochaperone and a nucleotide exchange factor (NEF). The aim of this study was to identify the residues involved in the interaction of these PfHsp70s with their peptide substrates, their J-domain cochaperones and potential NEFs. These residues were then mapped to three-dimensional (3D) structures of the proteins, modelled in three different conformations; each representing a different stage in the ATPase cycle. Additionally, these proteins were compared to different types of Hsp70s from a variety of different organisms and sequence features found to be specific to each PfHsp70 were mapped to their 3D structures. Finally, a novel modelling method was suggested, in which the structures of templates were remodelled to improve their quality before they were used in the homology modelling process. Based on the analysis of residues involved in interactions with other proteins, it was revealed that each PfHsp70 displayed features that were specific to its cellular localisation and each type of Hsp70 was predicted to interact with a different set of NEFs. The study of conserved features in each PfHsp70 revealed that PfHsp70-x displayed various sequence features atypical of both Plasmodium cytosolic Hsp70s and cytosolic Hsp70s in general. Additionally, residues conserved specifically in Hsp70s of Apicomplexa, Plasmodium and P. falciparum were identified and mapped to the each PfHsp70 model. Although these residues were too numerous to reveal any information of specific value, these models may be useful for the purposes of aiding the design of drug compounds against each PfHsp70. Finally, the novel modelling approach did show some promise. Half of the models produced using the modified templates were of a higher quality than their counterparts modelled using the original templates. This approach does still require a lot of validation work and statistical evaluation. It is hoped that it could prove to be a useful approach to homology modelling when the only templates available are poor quality structures.
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- Date Issued: 2012
a pH-metric speciation and anti-diabetic study of oxovanadium (IV) amino acid derivatives
- Authors: Gundhla, Isaac Zvikomborero
- Date: 2011 , 2011-03-15
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4399 , http://hdl.handle.net/10962/d1006691
- Description: Novel oxovanadium(IV) complexes of glycine, ʟ-alanine, 1-methylimidazole-2-carboxylic acid, imidazole-2-caboxylic acid and imidazole-4-carboxylic acid were synthesized and isolated in the solid state. The ligands and complexes were characterized by elemental analysis, melting point, NMR, IR and UV-vis spectroscopy. The IR studies showed that glycine and ʟ-alanine coordinate monodentately through the amine nitrogen whilst the imidazole-carboxylic acid derivatives assume a bidentate chelation. The electronic spectroscopic studies indicate distorted octahedral geometry for the oxovanadium complexes of amino acids and a square pyramidal geometry for oxovanadium(IV) complexes of imidazole carboxylic acid derivatives. The reaction of vanadyl (VO2+) with glycine, ʟ-alanine, imidazole-2-cabrboxylic acid, imidazole-4-carboxylic acid and 1-methylimidazole-2-carboxylic acid was studied in aqueous solution by pH-potentiometry under oxygen and carbon dioxide-free conditions. The data obtained from these titrations were used to calculate the protonation and stability constants. The results showed that all ligands are suitable for bidentate coordination in the formation of monomeric species although the solid state studies of the oxovanadium(IV) complexes of amino acids showed a monodentate coordination. The overall stability constants for the (VIVO)-ʟ-alanine system (log β120 = 18.27(6)), (VIVO)-glycine system (β120 = 17.22(6)), (VIVO)-imidazole-4-carboxyic acid (β120 = 11.38(8)), (VIVO)-imidazole-2-carboxylic acid (β120 = 11.62(6)) and (VIVO)-1-methylimidazole-2-carboxylic acid (β120 = 15.49(9)) were obtained. The calculations for the species distribution in the experimental pH range showed that the neutral bis-coordinated complexes are dominant over the biological pH range. The glucose uptake effect of oxovanadium(IV) complex of ʟ-alanine, imidazole-4-carboxylic acid, imidazole-2-carboxylic acid and 1-methylimidazole-2-carboxylic acid was investigated using 3T3-L1 adipocytes, Chang liver and C2C12 muscle cells at various concentrations. The compounds had significant glucose uptake on Chang liver cells only at a concentration of 0.1-10 μM whilst in the C2C12 muscle and 3T3-L1 cells the compounds showed little to no activity probably due to the lower concentrations employed as a result of the cytotoxicity of these compounds on these two cell lines.
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- Date Issued: 2011
An analysis of bank risk management and its relevance for the non-bank corporate sector
- Authors: Dietrich, David Roland
- Date: 2007
- Subjects: Bank management , Risk management , Corporations -- Finance , Financial institutions , Banks and banking
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:949 , http://hdl.handle.net/10962/d1002683 , Bank management , Risk management , Corporations -- Finance , Financial institutions , Banks and banking
- Description: This thesis, entitled “An analysis of bank risk management and its relevance for the non-bank corporate sector”, investigates the extent to which financial risk management by the banking sector can be applied to the non-bank corporate sector. As banks’ risk management techniques are more sophisticated than those of the non-bank corporate sector we have endeavoured to ascertain the applicability of these established risk management methods to the non-bank corporate sector. The main objectives of this study were to analyse the banking sectors’ risks and management thereof, and compare them to the risks faced by the nonbank corporate sector. This analysis was then used to present a theoretical financial risk management model for the corporate sector. This analysis was conducted using qualitative research. The thesis engaged in an in-depth investigation of financial risk management through a documentary, literature and media analysis. It was elucidated that not all companies face the same financial risks and therefore each company requires its own unique financial risk management model. Furthermore, it was established that there are several risks that both banks and non-bank corporates are subjected to. However, the management of these risks is not necessarily the same for these two types of institutes. This thesis concludes by putting forward a financial risk management model which presents all the possible financial risks that non-bank corporates may face.
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- Date Issued: 2007
The establishment of normative data on Xhosa-speaking high school learners using the ImPACT 3.0 programme
- Authors: Salman-Godlo, Noluthando Cikizwa
- Date: 2006
- Subjects: Brain -- Concussion -- South Africa , Sports -- Psychological aspects -- South Africa , Sports injuries -- Psychological spects , Neuropsychological tests , ImPACT 3.0
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3048 , http://hdl.handle.net/10962/d1002557 , Brain -- Concussion -- South Africa , Sports -- Psychological aspects -- South Africa , Sports injuries -- Psychological spects , Neuropsychological tests , ImPACT 3.0
- Description: Concussion is a common form of brain injury, especially amongst sports players of all age groups. ImPACT is a valid and reliable measure of a variety of cognitive functions commonly affected by such injuries, which allows for objective return-to-play decision making (Iverson, Lovell, & Collins, 2003). However, studies show that the transfer of such tests from one ethnic group to another without appropriate standardization is highly problematic (Ardila, 1995). Thus, the relative absence of South African normative data for the ImPACT 3.0 programme is an issue for concern. Consequently, this study aimed to establish norms for semi-rural Xhosa-speaking schoolboys with an advantaged education (ages 14, 16 and 18) for the ImPACT 3.0 programme as administered in English. Administrative and linguistic difficulties that were experienced by individuals during completion of the battery were also identified. Finally, the study included a comparison of the percentile scores of this sample to the USA norms for boys of a similar age group. Subtests scores were generated for 70 schoolboys and the data were then subjected to statistical analysis. A significant difference between English proficiency of the Grade 8 and Grade 12 boys was found. This indicates the importance of including an English proficiency test with the ImPACT battery when assessing such populations. No other significant differences were found between these age group samples. Although this requires further investigation, the comparison of the USA and SA percentiles suggests the use of local norms for this population. South African boys in this study consistently scored lower than the USA sample. Finally, it is recommended that symptom selfreports should be verbally investigated with each boy after testing, given indications of comprehension problems. In closing, limitations and future possible studies are discussed.
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- Date Issued: 2006
Growth, feeding and sex change in the sequential protandric shrimp Nauticaris marionis Bate 1888 at the Prince Edward Islands (Southern Ocean)
- Authors: Vumazonke, Lukhanyiso Unam
- Date: 2005
- Subjects: Shrimps -- Prince Edward Islands , Shrimps -- Feeding and feeds , Shrimps -- Nutrition , Shrimps -- Growth
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5704 , http://hdl.handle.net/10962/d1005390 , Shrimps -- Prince Edward Islands , Shrimps -- Feeding and feeds , Shrimps -- Nutrition , Shrimps -- Growth
- Description: Demographic parameters and the general biology of the subantarctic shrimp Nauticaris marionis from the Prince Edward Islands were investigated. The carapace length is the most accurate indicator of body size and it was confirmed that N. marionis is a partially protandric hermaphrodite. Gravid females of N. marionis observed mainly in March with negligible hatching persisting until April/May. The majority of juveniles develop into males. Juveniles are characterised by an appendage on the endopodite of the first pleopod called the appendix interna or a.i.1. Juveniles that develop into males do so by growing a further appendage on the endopodite of the second pleopod. This appendage characterises males and is called the appendix masculina (or a.m.). Juveniles may develop directly into primary females through the development of an ovary and the loss of the a.i.1. The sequence differs among individuals, with some developing the ovary before losing the a.i.1 and others losing the a.i.1 first. Loss of the a.i.1 appears to be by shedding during a single moult, rather than by atrophy. Females can also develop by an alternative route as secondary females. Such animals first become males with an a.m. and then develop an ovary, thus forming an intermediate form called a tertium quid, or “third thing”. Again, there are two forms of tertium quid. Tertia quae a have the a.m. as well as the a.i.1. Tertia quae b have the a.m. in combination with an ovary but no a.i.1. Either form of tertium quid can develop into a secondary female through loss of the a.m., and in the case of the tertium quid a, loss of the a.i.1. It is unclear whether sexual differentiation occurs in the plankton or just after N. marionis settles on the benthos. The results of gut content analysis suggest that N. marionis is an opportunistic feeder, preying on a variety of prey with a preference for detritus, benthic amphipods and gastropods. Cannibalism of conspecific pleopods by large individuals of N. marionis occurred mostly in females, particularly in incubation containers. Cannibalism also occurs in males, and its occurrence depends on individual size, not gender. No diel patterns were observed in the feeding activity of N. marionis. In situ daily rations of males (carapace length <7mm) and females (>7mm) were equivalent to ≈10% and ≈5% of body dry weight, respectively. The von Bertalanffy growth curve parameters were empirically identified, by cohort analysis of data collected during 4 years, as K = 0.22239/year, L[subscript]∞ = 14.05789mm, t₀ = -0.05174, L₀ = 0.16083mm. N. marionis can survive up to seven years under natural conditions.
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- Date Issued: 2005
Static analysis of functional languages
- Authors: Mountjoy, Jon-Dean
- Date: 1994 , 2012-10-10
- Subjects: Functional programming languages
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4669 , http://hdl.handle.net/10962/d1006690 , Functional programming languages
- Description: Static analysis is the name given to a number of compile time analysis techniques used to automatically generate information which can lead to improvements in the execution performance of function languages. This thesis provides an introduction to these techniques and their implementation. The abstract interpretation framework is an example of a technique used to extract information from a program by providing the program with an alternate semantics and evaluating this program over a non-standard domain. The elements of this domain represent certain properties of interest. This framework is examined in detail, as well as various extensions and variants of it. The use of binary logical relations and program logics as alternative formulations of the framework , and partial equivalence relations as an extension to it, are also looked at. The projection analysis framework determines how much of a sub-expression can be evaluated by examining the context in which the expression is to be evaluated, and provides an elegant method for finding particular types of information from data structures. This is also examined. The most costly operation in implementing an analysis is the computation of fixed points. Methods developed to make this process more efficient are looked at. This leads to the final chapter which highlights the dependencies and relationships between the different frameworks and their mathematical disciplines. , KMBT_223
- Full Text:
- Date Issued: 1994
Explanation of the geological map of the country east of Kariba
- Authors: Broderick, T J
- Date: 1977
- Subjects: Geology -- Kariba, Lake (Zambia and Zimbabwe) -- Maps , Geology -- Kariba, Lake (Zambia and Zimbabwe)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5075 , http://hdl.handle.net/10962/d1014650
- Description: The area covers part of the western end of the Zambezi Metamorphic Belt as it is known in Rhodesia. Most of the rocks are paragneisses of various ages that have suffered a long and complex history which has taken them into the highest facies of metamorphism and into the realm of granitization. Only the Karoo sediments of the Zambezi Valley are unaffected by these metamorphic events. From the scanty geochronological results obtainable from the north of Rhodesia, the history of this area started more than 2 500 million years ago. In the east and south-east of the mapped area are a group of highly migmatized granitic gneisses which represent a continuation westwards of similar rocks found in the area described in Bulletin 51 by Wiles (1961}. These Urungwe Paragneisses are regarded as forrning the basement on which all other rocks in the area lie, although their relationship with the Basement Complex is unknown. Climatically Kariba is hot and humid. Mean summer temperatures average 30°C (86°F), with temperatures in October that often exceed 40°C (100°F). Away from the Lake the humidity decreases and the increased altitudes above the Escarpment have a cooling effect. The township's mean annual rainfall is 665 millimetres (26,2 inches), most of which falls in the months between November and February. Basically. the area is well timbered but population pressures in the tribal areas, and depredation by elephants elsewhere, have made serious inroads upon the natural vegetation. The gneissic terrain above the Escarpment is characterized by mufuti trees (Brachystegia boehmiz). The baobab (Adansonia digitata) is common in the larger river valleys and in the low-lying area surrounding the lake shore where it occurs together with mopane (Colophospermum mopane) and thick jessie bush. In the river valleys, trees typical of the Zambezi Valley are common and include the tamarind (Tamarindus indica), mumvey (Kigelia africana) and Steculia species. Buffalo beans (Mucuma coriacea) are not uncommon in grassy river-beds. Physiographically, the area can be subdivided into three distinct regions, all of which have a marked geological control. They are- (1) The fault-lined Gwembe trough which has subsequently been inundated by the waters of Lake Kariba to an average altitude of 487 metres (1 600 feet) above sea level since the completion of the dam across the upstream entrance to the Kariba Gorge in 1960. The fiat land that now forms part of the lake shore is underlain by sediments of Karoo age and these, in the mapped area, occupy the Charara and Gachegache Basins, that lie to the north and south respectively of the Msango Range. These fiat-lying areas give way sharply to the gneissic terrain of the Zambezi Metamorphic Belt along the fault-lined Zambezi Escarpment. (2) The northern boundary of the area and the Msango Range are underlain by metasediments of the Makuti Group. The relief is strongly influenced by the regional geological structure of these complexly folded rocks with resistant meta-arkose and quartzite forming the sharp ridges and metapelites occupying the valleys. The ridges and valleys trend eastwards in the Msango Range, but along the northern boundary they trend north-westwards. (3) The linear topographic features of the Makuti Group terrain give way southwards to the older gneisses along an abrupt scarp edge, the base of which is marked by the Tsororo River. This terrain of gneisses is very rugged and highly dissected above the Zambezi Escarpment until it flattens out, at about 900 metres (2 950 feet) above sea level, into the Urungwe Tribal Trust Lands. In the rugged country above the Escarpment, granulites of the Piriwiri Group stand out above the gneisses as steep-sided conical bills. The country rises in a series of fault-lined steps to its highest point, at Nyamangwe trigonometrical beacon, which stands at 1 336 metres (4 382 feet) above sea level.
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- Date Issued: 1977
An investigation of the radio emission by the planet Jupiter on 18 Mc/s & 22 Mc/s
- Authors: Gruber, Georg Maria
- Date: 1963
- Subjects: Radio astronomy , Jupiter (Planet) -- Observations , Radio sources (Astronomy)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5524 , http://hdl.handle.net/10962/d1012113 , Radio astronomy , Jupiter (Planet) -- Observations , Radio sources (Astronomy)
- Description: This thesis describes the investigation carried out of the radio noise emitted by the planet Jupiter on 18 Mc/s and 22 Mc/s. Chapter I gives a brief introduction and outlines radioastronomical as well as astronomical ideas concerning Jupiter. A detailed survey of the research done to date including some of the hypotheses formulated by previous workers is presented in Chapter II . Chapter III deals with the apparatus used in this research. Two similar sets of apparatus were used. The aerials were folded dipoles. The signals were fed to the receiver, an R 206 , via a 300 ohm impedance line. To increase the gain an extra I -F. stage was included. This gave a gain of better than a 120 dB. To match the signals into the recorder a cathode follower was used. The operating procedure appears in the fourth chapter. The results obtained are discussed and tabulated at the end of the chapter. They agree with the findings made by previous workers, within the experimental limit. Histograms of the occurrence probability versus the revised System III coordinates are presented for each frequency and compared to previous ones. The final chapter contains the author ' s interpretation of the observed effects. A model based on a radiation analogous to the Cerenkov effect is found to be not inconsistent with the available data . Ending the chapter suggestions for further research are made.
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- Date Issued: 1963