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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Flexible Packaging Methodologies for Rapid Deployment of Customisable Component-based Digital Libraries

Mhlongo, Siyabonga 01 June 2006 (has links)
Software engineering is a discipline concerned with manufacturing or developing software. Software plays a pivotal role in everyday life, an absence of which will be devastating to a number of governmental, recreational and financial activities, amongst many others. One of the latest branches of software engineering, component-based software engineering, is concerned with the development of software systems using already existing components which speculatively will ensure rapid and inexpensive software development processes. Parallel with the advances in software engineering, the field of digital libraries — a field dealing with Web-based access to and management of structured digital content — has adopted this development model from software engineering to shift focus from developing and using traditionally monolithic software systems to developing and using more flexible component-oriented software systems. Since componentised development approaches are relatively recent, other areas such as packaging and managing component-based software systems still remain unattended to. This dissertation presents research on techniques and methodologies for packaging customisable component-based digital libraries such that deployment is rapid and flexibility is not compromised. Although the reference point of this research was that of component-based digital library systems, it is believed that this research can be generalised across the family of Web-based component-based software systems. An outcome of this research was a prototype packaging system consisting of a pair of tools: a package builder tool and a package installer tool. This packaging system was developed to model the ideas and methodologies that were identified as important to the processes of packaging and installing component-based digital library systems. These tools consequently underwent a user evaluation study whereby they were evaluated for understandability, usability and usefulness to the processes of packaging and installing component-based digital libraries. A key contribution of this research was identifying requirements for a generic component packaging framework. For a component to be seen as ”fit-to-package”, it must posses the following at the very least: the component must be configurable automatically; the component must have a formal description of its dependency software; there must be formal descriptions that describe individual components as well as systems composed of components; and there must be a way whereby installation questions are formally encoded such that components are able to correctly receive configuration information. In totality, this research has shown that component-oriented software development approaches can benefit from an infrastructure which allows for component-based software systems to be composed, distributed and installed effortlessly.
2

Universal Web Application Server

Nyirenda, Mayumbo 01 May 2008 (has links)
The growth of the World Wide Web has in large part been made possible by the technologies that power it. These are the Web servers and Web browsers that many take for granted. Each has evolved to support the changing needs of users of the WWW from simple static text to highly interactive and dynamic multimedia. The Web servers, in particular, have evolved into a spectrum of different technologies to support what are now known as Web applications. These are usually installed and accessed through a Web server. Security is a problem in Web server environments and therefore the Web servers are usually run as an un-privileged user. Performance is another problem as some of these technologies require re-initialization of the execution environment with every subsequent request. These security and performance shortcomings have been dealt with by numerous Web application technologies. Most of these technologies are language-centric and seek solutions to the security and performance shortcomings independently of each other. The universal Web application server is proposed as an alternative solution addressing the security, language dependence and performance shortcomings of existing technologies. It has support for multiple authors in a secure environment with support for multiple implementation technologies (languages) using persistent interpreters to enhance performance. Test results from the performance evaluation show that the introduction of the layers of processing contributes a small percentage to the total request processing time and that the universal Web application server can perform comparably to other Web application servers. Tests with twenty users also showed that packaging and deploying Web applications in the universal Web application server is an easy and viable approach. Moreover, the installation of PhpBB2 in the universal Web application server demonstrates that it can be used with realistic Web applications. A universal Web application server that provides an efficient, secure and language independent environment has been developed and thoroughly evaluated demonstrating that a Web application server that addresses the shortcomings of existing technologies is feasible.
3

Investigating the Efficacy of XML and Stylesheets to Render Electronic Courseware for Multiple Learning Styles

du Toit, Masha 01 June 2007 (has links)
The objective of this project was to test the efficacy of using Extensible Markup Language (XML) - in particular the DocBook 5.0b5 schema - and Extensible Stylesheet Language Transformation (XSLT) to render electronic courseware that can be dynamically re-formatted according to a student’s individual learning style. The text of a typical lesson was marked up in XML according to the DocBook schema, and several XSLT stylesheets were created to transform the XML document into different versions, each according to particular learning needs. These learning needs were drawn from the Felder-Silverman learning style model. The notes had links to trigger JavaScript functions that allowed the student to reformat the notes to produce different views of the lesson. The dynamic notes were tested on twelve users who filled out a feedback questionnaire. Feedback was largely positive. It suggested that users were able to navigate according to their learning style. There were some usability issues caused by lack of compatibility of the program with some browsers. However, the user test is not the most critical part of the evaluation. It served to confirm that the notes were usable, but the analysis of the use of XSLT and DocBook is the key aspect of this project. It was found that XML, and in particular the DocBook schema, was a useful tool in these circumstances, being easy to learn, well supported and having the appropriate structure for a project of this type. The use of XSLT on the other hand was not so straightforward. Learning a declarative language was a challenge, as was using XSLT to transform the notes as necessary for this project. A particular problem was the need to move content from one area of the document to another - to hide it in some cases and reveal it in others. The solution was not straightforward to achieve using XSLT, and does not take proper advantage of the strengths of this technology. The fact that the XSLT processor uses the DOM API, which necessitates the loading of the entire XML document into memory, is particularly problematic in this instance where the document is constantly transformed and re-transformed. The manner in which stylesheets are assigned, as well as the need to use DOM objects to edit the source tree, necessitated the use of JavaScript to create the necessary usability. These mechanisms introduced a limitation in terms of compatibility with browsers and caused the program to freeze on older machines. The problems with browser compatibility and the synchronous loading of data are not insurmountable, and can be overcome with the appropriate use of JavaScript and the use of asynchronous data retrieval as is made possible by the use of AJAX.
4

Individual Document Management Techniques: an Explorative Study

Sello, Mpho Constance 01 June 2007 (has links)
Individuals are generating, storing and accessing more information than ever before. The information comes from a variety of sources such as the World Wide Web, email and books. Storage media is becoming larger and cheaper. This makes accumulation of information easy. When information is kept in large volumes, retrieving it becomes a problem unless there is a system in place for managing this. This study examined the techniques that users have devised to make retrieval of their documents easy and timely. A survey of user document management techniques was done through interviews. The uncovered techniques were then used to build an expert system that provides assistance with document management decision-making. The system provides recommendations on file naming and organization, document backup and archiving as well as suitable storage media. The system poses a series of questions to the user and offers recommendations on the basis of the responses given. The system was evaluated by two categories of users: those who had been interviewed during data collection and those who had not been interviewed. Both categories of users found the recommendations made by the system to be reasonable and indicated that the system was easy to use. Some users thought the system could be of great benefit to people new to computers.
5

A lightweight interface to local Grid scheduling systems

Parker, Christopher P 01 May 2009 (has links)
Many complex research problems require an immense amount of computational power to solve. In order to solve such problems, the concept of the computational Grid was conceived. Although Grid technology is hailed as the next great enabling technology in Computer Science, the last being the inception of the World Wide Web, some concerns have to be addressed if this technology is going to be successful. The main difference between the Web and the Grid in terms of adoption is usability. The Web was designed with both functionality and end-users in mind, whereas the Grid has been designed solely with functionality in mind. Although large Grid installations are operational around the globe, their use is restricted to those who have an in-depth knowledge of its complex architecture and functionality. Such technology is therefore out of reach for the very scientists who need these resources because of its sheer complexity. The Grid is likely to succeed as a tool for some large-scale problem solving as there is no alternative on a similar scale. However, in order to integrate such systems into our daily lives, just as the Web has been, such systems need to be accessible to ``novice'' users. Without such accessibility, the use and growth of such systems will remain constrained. This dissertation details one possible way of making the Grid more accessible, by providing high-level access to the scheduling systems on which Grids rely. Since ``the Grid'' is a mechanism of transferring control of user submitted jobs to third-party scheduling systems, high-level access to the schedulers themselves was deemed to be a natural place to begin usability enhancing efforts. In order to design a highly usable and intuitive interface to a Grid scheduling system, a series of interviews with scientists were conducted in order to gain insight into the way in which supercomputing systems are utilised. Once this data was gathered, a paper-based prototype system was developed. This prototype was then evaluated by a group of test subjects who set out to criticise the interface and make suggestions as to where it could be improved. Based on this new data, the final prototype was developed firstly on paper and then implemented in software. The implementation makes use of lightweight Web 2.0 technologies. Designing lightweight software allows one to make use of the dynamic properties of Web technologies and thereby create more usable interfaces that are also visually appealing. Finally, the system was once again evaluated by another group of test subjects. In addition to user evaluations, performance experiments and real-world case studies were carried out on the interface. This research concluded that a dynamic Web 2.0-inspired interface appeals to a large group of users and allows for greater flexibility in the way in which data, in this case technical data, is presented. In terms of usability- the focal point of this research- it was found that it is possible to build an interface to a Grid scheduling system that can be used by users with no technical Grid knowledge. This is a significant outcome, as users were able to submit jobs to a Grid without fully comprehending the complexities involved with such actions, yet understanding the task they were required to perform. Finally, it was found that the use of a lightweight approach in terms of bandwidth usage and response time is superior to the traditional HTML-only approach. In this particular implementation of the interface, the benefits of using a lightweight approach are realised approximately halfway through a typical Grid job submission cycle.
6

Large Image Support in Digital Repositories

Nel, Marius Francois 01 January 2011 (has links)
Many universities, libraries, government organisations and companies are implementing digital repositories to collect, preserve, administer and distribute their collections via the World Wide Web. In the process of building these digital archives and collections, images such as maps are often are captured in an uncompressed, high-resolution format to preserve as much detail as possible. This process, of high-resolution archiving gives rise to the problem of providing the end-user with access to these large (high-resolution) images, such as maps. This dissertation investigates methods of storing and delivering large images over the Internet while limiting the amount of data being transferred; and also documents efforts to incorporate large image support within the DSpace platform. An end-user usability study of various large image support solutions was conducted to establish how current digital repository large image solutions compared to commercial large image solutions. The study showed that the commercial large image solutions were superior to current digital repository solutions. A prototype large image solution was developed with a specific aim to provide DSpace with mechanisms to import and deliver large images in a bandwidth-conscious manner. It was found that by implementing and extending currently available open source large image processing software, large image support could be provided to the DSpace platform with minimal or no modification to the DSpace source code. An end user evaluation study was conducted to establish the usability and effectiveness of the prototype large image support solution. It was found that the prototype system provided an easy to use solution that provides DSpace with an effective large image archiving and delivery mechanism.
7

Telecommuting in the Developing World: A Case of the Day-Labour Market

Chepken, Christopher 01 January 2013 (has links)
Information and Communication Technologies (ICTs) in general, and mobile phones in particular, have demonstrated positive outcomes in the various social transformation and human development dimensions. As a result, many researchers have focused on ICTs innovations targeting the poor. Among the poor are the low-skilled day-labourers who belong to the Day-labour Market (DLM), which is also made up of employers, job-brokers and intermediary organisations. The DLMs’ main activities involve a great deal of travelling in search of jobs by workers and a search for workers by employers. These travels place heavy economic pressure on the day-labourers, hence reducing their net earnings while they struggle with extreme poverty. The first objective of our study was to find out how and which ICT interventions can be used to alleviate the challenges faced by the DLM stakeholders. The nature of our problem resembled studies that use ICTs to reduce travel distance. Such studies fall under subjects such as teleactivities and teleworking/telecommuting, and advocate for prospects of working anywhere anytime. These studies have not received much research attention in the developing world. They have mainly been done in the developed world, and mostly on white-collar workers and organisations. This brought about our second objective: to find out whether the ICT interventions for the DLM could be studied under teleworking/telecommuting and whether the telecommuting benefits can be realised for the blue-collar workers. Our research methodology was Action Research applying three case studies. We used participant observation and both structured and unstructured interviews for qualitative data collection and questionnaires to collect quantitative data. Contextual inquiry, prototyping and technology probe was applied as our design technique. The prototypes were evaluated in-situ to assess usability and uncover user experience. We mainly employed qualitative data analysis, but where appropriate, triangulated with quantitative data analysis. The research outcomes were divided into three categories: (1) the knowledge on the DLM characteristics which depicted different forms of the DLM and shaped our design process, (2) the DLM software designs tested as prototype applications and software artefacts deployed for use by the DLM and (3) the meaning and the state of telecommuting/teleworking before and after our experiments in the DLM. In the first category, appreciating the challenges faced by our primary target users, the day-labourers, helped shape our designs and our inquiry to include intermediation. With regard to the prototype applications, they included the remote mobile applications and the web-based server side software systems. Although most of these applications where meant for proof of concept, some of them ended up being implemented as fully functional systems. Finally, in the third finding, travel reduction using ICTs (mainly the mobile phones) had been practised by some of the DLM stakeholders even before the commencement of our study. After our intervention, we discovered that implementing telecommuting/teleworking within the DLM may be possible, but with a raft of redefinitions and changes in technology innovations. We therefore identified factors to consider when thinking of implementing telecommuting among blue-collar employees, organisations and employers.
8

Investigating the Impact of Organised Technology-driven Orchestration on Teaching

Phiri, Lighton 01 October 2018 (has links)
Orchestration of learning involves the real-time management of activities performed by educators in learning environments, with a particular focus on the effective use of technology. While different educational settings present unique problems, the common challenges have been noted to primarily be as a result of multiple heterogeneous activities and their associated intrinsic and extrinsic constraints. In addition to these challenges, this thesis argues that the complexities of orchestration are further amplified due to the ad hoc nature of the approaches and techniques used to orchestrate learning activities. The thesis proposes a streamlined approach to technology-driven orchestration of learning, in order to address these challenges and complexities. Specifically, the thesis proposes an organised approach that focuses on three core aspects of orchestration: activity management, resource management and sequencing of learning activities. Orchestration was comprehensively explored in order to identify the core aspects essential for streamlining technology-driven orchestration. Proof-of-concept orchestration toolkits, based on the proposed orchestration approach, were implemented and evaluated in order to assess the feasibility of the approach, its effectiveness and its potential impact on the teaching experience. Comparative analysis and guided orchestration controlled studies were conducted to compare the effectiveness of ad hoc orchestration with streamlined orchestration and to measure the orchestration load, respectively. In addition, a case study of a course that employed a flipped classroom strategy was conducted to assess the feasibility of the proposed approach. The feasibility was further assessed by integrating a workflow, based on the proposed approach, that facilitates the sharing of reusable orchestration packages. The results from the studies suggest that the streamlined approach is more effective when compared to ad hoc orchestration and has a potential to provide a positive user experience. The results also indicate that the approach imposes acceptable orchestration load during scripting of learning activities. Case studies conducted in authentic educational settings suggest that the approach is feasible, and potentially applicable to useful practical usage scenarios. The long-term implications are that streamlining of technology-driven orchestration could potentially improve the effectiveness of educators when orchestrating learning activities.
9

Transcription of the Bleek and Lloyd Collection using the Bossa Volunteer Thinking Framework

Munyaradzi, Ngoni 01 November 2013 (has links)
The digital Bleek and Lloyd Collection is a rare collection that contains artwork, notebooks and dictionaries of the earliest habitants of Southern Africa. Previous attempts have been made to recognize the complex text in the notebooks using machine learning techniques, but due to the complexity of the manuscripts the recognition accuracy was low. In this research, a crowdsourcing based method is proposed to transcribe the historical handwritten manuscripts, where volunteers transcribe the notebooks online. An online crowdsourcing transcription tool was developed and deployed. Experiments were conducted to determine the quality of transcriptions and accuracy of the volunteers compared with a gold standard. The results show that volunteers are able to produce reliable transcriptions of high quality. The inter-transcriber agreement is 80% for |Xam text and 95% for English text. When the |Xam text transcriptions produced by the volunteers are compared with the gold standard, the volunteers achieve an average accuracy of 69.69%. Findings show that there exists a positive linear correlation between the inter-transcriber agreement and the accuracy of transcriptions. The user survey revealed that volunteers found the transcription process enjoyable, though it was difficult. Results indicate that volunteer thinking can be used to crowdsource intellectually-intensive tasks in digital libraries like transcription of handwritten manuscripts. Volunteer thinking outperforms machine learning techniques at the task of transcribing notebooks from the Bleek and Lloyd Collection.

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