A bi-directional SOAP/SMS gateway service
- Authors: Halse, Guy A , Terzoli, Alfredo , Wells, George C
- Date: 2002
- Subjects: Broadband 2 SATNAC 2002
- Language: English
- Type: Conference paper
- Identifier: vital:6600 , http://hdl.handle.net/10962/d1008293
- Description: Many applications need the ability to do real-time notification when events occur. Often the people who need to be kept aware of events are in a remote location. This paper looks at a bi-directional gateway between networked computers and the GSM short message service. The gateway is implemented as a web service, and uses the Simple Object Access Protocol to facilitate data communication. The service interacts with a database in order to facilitate retrieval of sent or received messages, as well as provide accounting abilities. It is intended as a practical proof-of-concept application demonstrating some ofdemonstrating some of the capabilities of the Simple Object Access Protocol.
- Full Text:
- Date Issued: 2002
Accelerated sludge solubilisation under sulphate reducing conditions: the effect of hydrolytic enzymes on sludge floc size distribution and EPS composition
- Authors: Akhurst, P , Rose, Peter D , Whiteley, Chris G , Pletschke, Brett I
- Date: 2002
- Language: English
- Type: Conference paper
- Identifier: vital:6455 , http://hdl.handle.net/10962/d1010430
- Description: Extracellular polymeric substances (EPS) are the construction materials for microbial aggregates such as biofilms, flocs and sludge, and greatly contribute to the structural integrity of sludge flocs in wastewater treatment processes. The loss of integrity of the sewage sludge floc is believed to be due to enhanced hydrolysis of important structural components such as lignin, protein and cellulose in the sludge floc matrix. The mechanism of enhanced sludge floc fracture, due to the action of enzymes hydrolysing these structural components, remains a key element in our understanding of how the floc integrity in systems utilising a sulphate reducing system is compromised. A range of relatively non-specific exogenous enzymes (ß-glucosidase, cellulase, proteases: trypsin, pronase E and chymotrypsin) were added to a sulphidogenic bioreactor- (containing both sulphate reducing bacteria (SRB) and a methanogenic bacterial system) and a (control) methanogenic bioreactor sample, and the effect of these enzymes on sludge floc size (diameter) distribution and EPS composition was investigated. Sludge samples from the bioreactors were examined under bright field and differential interference contrast light microscopy. Proteolytic and glucohydrolytic activity of the enzymes were monitored using standard enzyme assaying techniques, and Bradford, Somogyi-Nelson, and total carbohydrate assays were performed to establish the composition of the EPS (after extraction with 3% (v/v) glutaraldehyde and Sephacryl S-400 size exclusion chromatography). Sludge flocs present in the sulphidogenic environment of the sulphidogenic bioreactor were found to have smaller diameters than their counterparts present in the methanogenic bioreactor. The addition of hydrolytic (i.e. proteolytic and glycohydrolytic) enzymes resulted in an increased rate of matrix hydrolysis, leading to increased rates of floc fracture and deflocculation. The presence of ß-glucosidase, cellulase, and proteases naturally residing within the sludge floc was confirmed. We propose that the addition of commercially available enzymes may be prohibitively costly on a large scale, and that the activity of the enzymes naturally residing within the floc matrix be optimised or enhanced. As the bulk of the EPS was shown to be composed of mainly polysaccharides, we propose that by increasing the activity of the naturally occurring ß-glucosidases residing within the floc matrix, the process of deflocculation may be enhanced. As sulphide has been shown to increase the activity of this very important key enzyme, we propose that this is one of the contributing factors why sludge solubilisation is accelerated under sulphate reducing conditions.
- Full Text:
- Date Issued: 2002
Active learning for understanding land degradation : African Catchment Game and Riskmap
- Authors: Rowntree, Kate M , Fox, Roddy C
- Date: 2006
- Language: English
- Type: Conference paper
- Identifier: vital:6669 , http://hdl.handle.net/10962/d1006793
- Description: Land degradation is the result of the intersection of a complex set of biophysical and socio-economic factors. The capacity of an individual or community to address land degradation is likewise constrained. While it is quite possible for professionals and learners to grasp the main issues around land degradation from a theoretical perspective, internalizing the reality of what it means to be the resource degrader is more difficult. We have developed two active learning methods that aim to address this problem. The first is the African Catchment Game, a role-playing game based on Graham Chapman’s Green Revolution Game, adapted for the southern Africa context and incorporating a land degradation component. In this game participants play out the complex dynamics of rural-urban-global linkages against a background of environmental hazards. The second is based on Save the Children Fund’s RiskMap computer simulation that models risk in terms of rural livelihoods for different income groups. Ethiopia is used as the example. This paper evaluates the two active learning techniques as tools for exploring the relationships between land degradation and poverty through an evaluation of participants’ experiences.
- Full Text:
- Date Issued: 2006
An appraisal of the applicability of development journalism in the context of public service broadcasting
- Authors: Banda, Fackson
- Date: 2006
- Language: English
- Type: Conference paper
- Identifier: vital:6322 , http://hdl.handle.net/10962/d1008548
- Description: The concept of ‘development journalism’ has, over time, become possessed by demons of all sorts of confusion. If we want to wrest any useful principles from the concept, it is important that we exorcise the demons it has come to be associated with, not least the demon of the postcolonial state’s blatant interference in the practice of journalism. This ‘demonisation’ of the concept is partly suggested by Shah’s observation that ‘development journalism’, central to many discussions of mass communication and development in the Third World, needs to be reconceptualised because deliberations about its validity and usefulness have been bogged down in arguments structured by Western notions of press freedom. The debate has diverted attention from important questions about how journalism can contribute to participatory democracy, security, peace, and other humanistic values (Shah 1996: 143). In this paper, therefore, I will, firstly, discuss the conceptual basis of development journalism. I will rely heavily on development communication theorising, which informs most of the discussions about development journalism. I want to demonstrate the historical ‘moments’ through which the concept has passed and, by so doing, point out the more redeemable features of the concept. Secondly, I will discuss the relevance of the development journalism paradigm to public service broadcasting. In conclusion, I will draw out some principles of development journalism and demonstrate how these can be implemented within the context of public service broadcasting.
- Full Text:
- Date Issued: 2006
An investigation into the time-saving benefits of using a computerised taxation program
- Authors: Forster, Rory , Stack, Elizabeth M
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: Conference paper
- Identifier: vital:6065 , http://hdl.handle.net/10962/d1004610
- Description: Software programs designed to calculate the tax liability of individuals and other types of tax entity are being designed and used with increasing frequency. Research done in the United States of America appears to indicate that these programs do not achieve any saving in time and, in fact, may take longer to use than to complete a tax return by hand. As the South African revenue collection system appears to be moving closer to a self-assessment system, where the calculation of tax owing will be the responsibility of the taxpayer, the research essay sets out to determine whether there is a saving in time when calculating a tax liability using a tax software program, instead of calculating it by hand. In addition, the research aims to determine how much time, on average, is saved or lost, using such a program, and whether there is any correlation between the time taken to perform a calculation by hand and that using the software program. It does so by comparing the average estimated time it would take to complete tax calculations for individuals by hand with the average time taken to complete the same tax calculations using a tax software program. The average time taken to do the calculations by hand is based on the time allocation given for questions by the authors of a published question bank for university students. The time taken using software is determined by using a stop-watch to time each question being processed. The results, subject to assumptions made in carrying out the research, show that there is a substantial saving in time using the software program. Based on the data, however, the results indicate a weak correlation between the estimated time taken to do a calculation by hand and the estimated time using the software program. Possible reasons for the weak correlation are discussed. A recommendation is also made for the standardization and certification of existing tax calculation software.
- Full Text:
- Date Issued: 2008
Bandwidth management with the Squid caching proxy server
- Authors: Halse, Guy A
- Date: 2006
- Language: English
- Type: Conference paper
- Identifier: vital:6975 , http://hdl.handle.net/10962/d1009335
- Description: Presentation on the use of the Squid caching proxy server as a tool for bandwidth management. This formed part of the International Network for the Availability of Scientific Publications' Bandwidth Management and Optimisation Open Source Tools and Solutions project, being a series of workshops conducted throughout the developing world.
- Full Text:
- Date Issued: 2006
Bioequivalence testing of topical dermatological formulations, the gap between science and legislation
- Authors: Schwarb, Fabian P , Smith, Eric W , Haigh, John M , Surber, Christian
- Date: 1998
- Language: English
- Type: Conference paper
- Identifier: vital:6341 , http://hdl.handle.net/10962/d1006608
- Description: Bioavailability concerns for topical dermatological products are complex and it is especially difficult to determine the bioequivalence of similar topical formulations. Since only small amounts of drug dispersed in an appropriate vehicle are applied to the skin, the amount of drug that actually reaches the systemic circulation is often too small to be easily quantified. Additionally, it can be argued that the relevance of any serum/plasma concentration-time curve of a topical agent is questionable, since the curve reflects the amount of drug after the active moiety has left the site of action. For some topical drugs e.g., topical corticosteroids, it is possible to perform a pharmacodynamic bioassay to obtain acceptable bioequivalence data. In this case, the intensity of the side effect of blanching (vasoconstriction) in the skin caused by topical corticosteroids can be measured. The response is directly proportional to the clinical efficacy, and the skin blanching assay has proved to be a reliable procedure for the determination of topical corticosteroid bioavailability. Recently, we had sight of the results of a topical bioequivalence study, which was conducted for the registration of a new generic corticosteroid cream formulation. In this trial the new formulation was compared to two equivalent product from the local market and bioequivalence was demonstrated by the investigators for all three products. These results were examined with interest as the respective reference products have been used repeatedly as standard formulations in our laboratory. However, one of these reference formulations has consistently shown superior bioavailability in our trials, but was not demonstrated to be superior in the study results examined. In the present publication an overview of topical bioequivalence testing in general is given and the difficulties occurring in practice, for topical corticosteroid formulations in particular, are demonstrated.
- Full Text:
- Date Issued: 1998
Chromametry: measuring precision of diurnal and local variation of human forearm skin colour
- Authors: Schwarb, Fabian P , Smith, Eric W , Haigh, John M , Surber, Christian
- Date: 1998
- Language: English
- Type: Conference paper
- Identifier: vital:6343 , http://hdl.handle.net/10962/d1006610
- Description: Chromameters are compact portable instruments used for the assessment of surface colour based on the tristimulus analysis of a reflected xenon light pulse, and have been used for the quantification of erythema in the study of irritant dermatitis, and corticosteroid-induced skin blanching in the vasoconstriction assay. The variability and the reproducibility of chromameter results were investigated since it is known that the location and application force of the measuring head on the skin and the orthostatic maneuver of the arms influence the colour measurement. Furthermore the diurnal variation and the homogeneity of forearm skin colour were investigated.
- Full Text:
- Date Issued: 1998
Classifying network attack scenarios using an ontology
- Authors: Van Heerden, Renier , Irwin, Barry V W , Burke, I D
- Date: 2012
- Language: English
- Type: Conference paper
- Identifier: vital:6606 , http://hdl.handle.net/10962/d1009326
- Description: This paper presents a methodology using network attack ontology to classify computer-based attacks. Computer network attacks differ in motivation, execution and end result. Because attacks are diverse, no standard classification exists. If an attack could be classified, it could be mitigated accordingly. A taxonomy of computer network attacks forms the basis of the ontology. Most published taxonomies present an attack from either the attacker's or defender's point of view. This taxonomy presents both views. The main taxonomy classes are: Actor, Actor Location, Aggressor, Attack Goal, Attack Mechanism, Attack Scenario, Automation Level, Effects, Motivation, Phase, Scope and Target. The "Actor" class is the entity executing the attack. The "Actor Location" class is the Actor‟s country of origin. The "Aggressor" class is the group instigating an attack. The "Attack Goal" class specifies the attacker‟s goal. The "Attack Mechanism" class defines the attack methodology. The "Automation Level" class indicates the level of human interaction. The "Effects" class describes the consequences of an attack. The "Motivation" class specifies incentives for an attack. The "Scope" class describes the size and utility of the target. The "Target" class is the physical device or entity targeted by an attack. The "Vulnerability" class describes a target vulnerability used by the attacker. The "Phase" class represents an attack model that subdivides an attack into different phases. The ontology was developed using an "Attack Scenario" class, which draws from other classes and can be used to characterize and classify computer network attacks. An "Attack Scenario" consists of phases, has a scope and is attributed to an actor and aggressor which have a goal. The "Attack Scenario" thus represents different classes of attacks. High profile computer network attacks such as Stuxnet and the Estonia attacks can now be been classified through the “Attack Scenario” class.
- Full Text:
- Date Issued: 2012
Coming to terms with the "Border War" in post-apartheid South Africa
- Authors: Baines, Gary F
- Date: 2008
- Language: English
- Type: Conference paper
- Identifier: vital:6157 , http://hdl.handle.net/10962/d1007077
- Description: If you are a white, male South African between the ages of about 35 and 60 it is very likely that you donned the nutria brown uniform of the South African Defence Force (SADF). Between 1967 and 1994 approximately 300 000 young white males were conscripted by the SADF. As far as most of these conscripts were concerned, there was no option other than heeding the call-up and performing national service or diensplig. Failure to do so meant harsh penalties. The alternatives were to object on conscientious (actually religious) grounds and face a six year jail sentence, or flee the country. And the obligation did not end with national service as conscripts were assigned to citizen force or commando units that were liable for periodical call-ups for camps that might have included deployment in the “operational areas” from 1974 or tours of duty in the black townships from 1984. Those - like myself - belonging to this national service generation were part-time soldiers for much of their adult lives. Most served willingly, some with patriotic fervour. Others did so reluctantly and with little enthusiasm.
- Full Text:
- Date Issued: 2008
Comparison of visual CR-200 and CR-300 chromameter data obtained from the corticosteroid-induced skin-blanching assay
- Authors: Schwarb, Fabian P , Smith, Eric W , Haigh, John M , Surber, Christian
- Date: 1998
- Language: English
- Type: Conference paper , text
- Identifier: vital:6344 , http://hdl.handle.net/10962/d1006611
- Description: In a recent Guidance document the American FDA recommended the use of a chromameterrather thanthe human eye for the assessment of the pharmacodynamic blanching response produced after topical application of corticosteroids. The purpose of this study was to investigate the appropriateness of the human eye and two types of chromameter for the estimation of skin blanching.
- Full Text:
- Date Issued: 1998
Creating a virtual classroom: evaluating the use of online discussion forums to increase teaching and learning activities
- Authors: Bezuidenhout, L Peta
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: Conference paper
- Identifier: vital:6070 , http://hdl.handle.net/10962/d1004635
- Description: In teaching large classes, the educationally beneficial informal interaction between students and between lecturer and students is generally reduced, while effective use of both students’ and lecturer’s time is often a challenge. During student consultations, especially over the already stressful test and examination periods, many of the questions asked by the students are the same or similar. The lecturer needs to respond to each query by providing the same detailed explanation for the problem, resulting in ineffective use of time for the lecturer, while students waste time waiting for an appointment, or more often, simply don’t bother to follow up on any queries they may have. Having a social presence is important for students’ cognitive development, but in a large class posing questions or interrogating issues during a lecture appears to be challenging for many students. It is often not easy for students to initiate discussions or establish relationships with peers or the lecturer due to feelings of vulnerability and due to the size and impersonal atmosphere of the lecture theatre. This paper deals with the introduction of online discussion forums in an introductory accounting course and the benefits and problems experienced by the students, tutors and lecturer as a result thereof. Feedback received from these participants is discussed. The introduction and use of these forums resulted in a virtual classroom being created, where significantly more teaching and learning activities took place, to the benefit of all participants. Participation could have been peripheral -in the form of simply reading discussions; or active – through posting questions, or responding to questions.
- Full Text:
- Date Issued: 2009
Creating a virtual classroom: evaluating the use of online discussion forums to increase teaching and learning activities in an introductory accounting class
- Authors: Bezuidenhout, L Peta
- Date: 2008
- Language: English
- Type: Conference paper
- Identifier: vital:6082 , http://hdl.handle.net/10962/d1008586
- Description: In teaching large classes, the educationally beneficial informal interaction between students and between lecturer and students is generally reduced, while effective use of both students' and lecturer's time is often a challenge. During student consultations, especially over the already stressful test and examination periods, many of the questions asked by the students are the same or similar. The lecturer needs to respond to each query by providing the same detailed explanation for the problem, resulting in ineffective use of time for the lecturer, while students waste time waiting for an appointment, or more often, simply don't bother to follow up on any queries they may have. Having a social presence is important for students' cognitive development, but in a large class posing questions or interrogating issues during a lecture appears to be challenging for many students. It is often not easy for students to initiate discussions or establish relationships with peers or the lecturer due to feelings of vulnerability and due to the size and impersonal atmosphere of the lecture theatre. This paper deals with the introduction of online discussion forums in an introductory accounting course and the benefits and problems experienced by the students, tutors and lecturer as a result thereof. Feedback received from these participants is discussed. The introduction and use of these forums resulted in a virtual classroom being created, where significantly more teaching and learning activities took place, to the benefit of all participants. Participation could have been peripheral - in the form of simply reading discussions; or active – through posting questions, or responding to questions.
- Full Text:
- Date Issued: 2008
Creating a virtual classroom: evaluating the use of online discussion forums to increase teaching and learning activities in an introductory accounting class
- Authors: Bezuidenhout, L Peta
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: Conference paper
- Identifier: vital:6069 , http://hdl.handle.net/10962/d1004630
- Description: In teaching large classes, the educationally beneficial informal interaction between students and between lecturer and students is generally reduced, while effective use of both students' and lecturer's time is often a challenge. During student consultations, especially over the already stressful test and examination periods, many of the questions asked by the students are the same or similar. The lecturer needs to respond to each query by providing the same detailed explanation for the problem, resulting in ineffective use of time for the lecturer, while students waste time waiting for an appointment, or more often, simply don't bother to follow up on any queries they may have. Having a social presence is important for students' cognitive development, but in a large class posing questions or interrogating issues during a lecture appears to be challenging for many students. It is often not easy for students to initiate discussions or establish relationships with peers or the lecturer due to feelings of vulnerability and due to the size and impersonal atmosphere of the lecture theatre. This paper deals with the introduction of online discussion forums in an introductory accounting course and the benefits and problems experienced by the students, tutors and lecturer as a result thereof. Feedback received from these participants is discussed. The introduction and use of these forums resulted in a virtual classroom being created, where significantly more teaching and learning activities took place, to the benefit of all participants. Participation could have been peripheral - in the form of simply reading discussions; or active – through posting questions, or responding to questions.
- Full Text:
- Date Issued: 2008
De La Rey rides (yet) again : Afrikaner identity politics and nostalgia in post-apartheid South Africa
- Authors: Baines, Gary F
- Date: 2009
- Language: English
- Type: Conference paper
- Identifier: vital:6158 , http://hdl.handle.net/10962/d1007078
- Description: In 2006 a relatively unknown South African artist with the stage name Bok van Blerk released his debut album called “De la Rey”. The album included a music video of the title track that calls upon the legendary Boer War general to save the volk (people) from the wantonly destructive strategies of the British imperial forces: the scorched earth policy and the subsequent internment of women and children in concentration camps. The British justified such extreme – some would say ‘genocidal’ – strategies so as to prevent non-combatants from supporting the irregular Boer soldiers. Although he did not believe that the war could be won on account of the overwhelming odds that the Boer forces faced, De la Rey still fought to the bitter end. Needless to say, he was on the losing side.
- Full Text:
- Date Issued: 2009
Demand-side management of internet bandwidth
- Authors: Halse, Guy A
- Date: 2008
- Language: English
- Type: Conference paper
- Identifier: vital:6607 , http://hdl.handle.net/10962/d1009463
- Description: Presentation on the demand-side management of Internet bandwidth, using Rhodes University as a case study, as presented at the DITCHE national techie event in September 2008.
- Full Text:
- Date Issued: 2008
Evaluating parts-of-speech taggers for use in a text-to-scene conversion system
- Authors: Glass, Kevin R , Bangay, Shaun D
- Date: 2005
- Language: English
- Type: Conference paper
- Identifier: vital:6603 , http://hdl.handle.net/10962/d1009323
- Description: This paper presents parts-of-speech tagging as a first step towards an autonomous text-to-scene conversion system. It categorizes some freely available taggers, according to the techniques used by each in order to automatically identify word-classes. In addition, the performance of each identified tagger is verified experimentally. The SUSANNE corpus is used for testing and reveals the complexity of working with different tagsets, resulting in substantially lower accuracies in our tests than in those reported by the developers of each tagger. The taggers are then grouped to form a voting system to attempt to raise accuracies, but in no cases do the combined results improve upon the individual accuracies. Additionally a new metric, agreement, is tentatively proposed as an indication of confidence in the output of a group of taggers where such output cannot be validated.
- Full Text:
- Date Issued: 2005
Exploring risk related to future climates through role-playing games: the African catchment game
- Authors: Rowntree, Kate M , Fraenkel, Linda A , Fox, Roddy C
- Date: 2009
- Language: English
- Type: Conference paper
- Identifier: vital:6671 , http://hdl.handle.net/10962/d1006807
- Description: Risk is the result of two interacting components: hazard and vulnerability. Climatic hazards are related to extrinsic factors such as drought or severe storms. Vul- nerability is the result of intrinsic factors that often arise from the socio-political- economic context. The interplay of risk and vulnerability is difficult to predict. Although computer models have been widely used to forecast climate related risk, albeit with con- siderable uncertainty, they can never capture sufficiently the vulnerability of human sys- tems to these hazards. Role-playing games can be used more realistically to simulate pos- sible outcomes of different climate change scenarios, and allow players to reflect on their significance. The authors have developed the African Catchment Game to simulate a wa- ter scarce African country. Risk can be modelled mechanistically by changing the nature of the annual rainfall input. Vulnerability can in part be modelled by changing the start- ing parameters (such as access to land and resources) and, secondly, through the unpredictable response of players to game dynamics. Players’ reflections demonstrate that through the game they become more aware of the concept of risk and the complex response of individuals and societies that determine their vulnerability to climatic hazards. This paper reflects on the potential for developing the game further as a tool for participatory learning around climate change, based on the authors’ experience of playing the game with participants from South Africa.
- Full Text:
- Date Issued: 2009
Firewalls at Rhodes
- Authors: Siebörger, David
- Date: 2006
- Language: English
- Type: Conference paper
- Identifier: vital:6610 , http://hdl.handle.net/10962/d1009522
- Description: A presentation on the use of Internet Firewalls at Rhodes University. This formed part of the International Network for the Availability of Scientific Publications' Bandwidth Management and Optimisation Open Source Tools and Solutions project, being a series of workshops conducted throughout the developing world.
- Full Text:
- Date Issued: 2006
From FidoNet to internet: the evolution of a national network
- Authors: Jacot-Guillarmod, Francois F
- Date: 1992
- Language: English
- Type: Conference paper
- Identifier: vital:6974 , http://hdl.handle.net/10962/101
- Description: The South African academic research network, UNINET-ZA, evolved within two years from a FidoNet mail gateway that distributed email via interactive Kermit links, to a dialup uucp network, to wide area TCP/IP, and finally to full Internet connectivity. While the majority of UNINET-ZA sites are now TCP/IP connected, elements of the original gatewaying techniques are still fulfilling useful functions - for example a TCP/IP <=> FidoNet gateway, and links into non-Unix, non-TCP/IP based systems.
- Full Text:
- Date Issued: 1992