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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

Effective Run-Time Management of Parallelism in a Functional Programming Context

Dermoudy, J January 2002 (has links) (PDF)
This thesis considers how to speed up the execution of functional programs using parallel execution, load distribution, and speculative evaluation. This is an important challenge given the increasing complexity of software systems, the decreasing cost of individual processors, and the appropriateness of the functional paradigm for parallelisation. Processor speeds are continuing to climb — but the magnitudes of increase are overridden by both the increasing complexity of software and the escalating expectation of users. Future gains in speed are likely to occur through the combination of today’s conventional uni-processors to form loosely-coupled multicomputers. Parallel program execution can theoretically provide linear speed-ups, but for this theoretical benefit to be realised two main hurdles must be overcome. The first of these is the identification and extraction of parallelism within the program to be executed. The second hurdle is the runtime management and scheduling of the parallel components to achieve the speed-up without slowing the execution of the program. Clearly a lot of work can be done by the programmer to ‘parallelise’ the algorithm. There is often, however, much parallelism available without significant effort on the part of the programmer. Functional programming languages and compilers have received much attention in the last decade for the contributions possible in parallel executions. Since the semantics of languages from the functional programming paradigm manifest the Church-Rosser property (that the order of evaluation of sub-expressions does not affect the result), sub-expressions may be executed in parallel. The absence of side-effects and the lack of state facilitate the availability of expressions suitable for concurrent evaluation. Unfortunately, such expressions may involve varying amounts of computation or require high amounts of data — both of which complicate the management of parallel execution. If the future of computation is through the formation of multicomputers, we are faced with the high probability that the number of available processing units will quickly outweigh the known parallelism of an algorithm at any given moment during execution. Intuitively this spare processing power should be utilised if possible. The premise of speculative evaluation is that it employs otherwise idle tasks on work that may prove beneficial. The more program components available for execution the greater the opportunity for speculation and potentially the quicker the program’s result may be obtained. The second impediment for the parallel execution of programs is the scheduling of program components for evaluation. Multicomputer execution of a program involves the allocation of program components among the available tasks to maximise throughput. We present a decentralised, speculation-cognate, load distribution algorithm that allocates and manages the distribution of program components among the tasks with the co-aim of minimising the impact on tasks executing program components known to be required. In this dissertation we present our implementation of minimal-impact speculative evaluation in the context of the functional programming language Haskell augmented with a number of primitives for the indication of useful parallelism. We expound four (two quantitative and two qualitative) novel schemes for expressing the initial speculative contribution of program components and provide a translation mechanism to illustrate the equivalence of the four. The implementation is based on the Glasgow Haskell Compiler (GHC) version 0•29 — the de facto standard for parallel functional programming research — and strives to minimise the runtime overhead of managing speculative evaluation. We have augmented the Graph reduction for a Unified Machine model (GUM) runtime system with our load distribution algorithm and speculative evaluation sub-system. Both are motivated by the need to facilitate speculative evaluation without adversely impacting on program components directly influencing the program’s result. Experiments have been undertaken using common benchmark programs. These programs have been executed under sequential, conservative parallel, and speculative parallel evaluation to study the overheads of the runtime system and to show the benefits of speculation. The results of the experiments conducted using an emulated multicomputer add evidence of the usefulness of speculative evaluation in general and effective speculative evaluation in particular.
2

A Peer to Peer Supply Chain Network

Goldsmith, B January 2004 (has links) (PDF)
Many papers have speculated on the possibility of applying peer-to-peer networking concepts to networks that exist in the physical world such as financial markets, business or personal communication and ad hoc networking. One such application that has been discussed in the literature has been the application of peer-to-peer to corporate supply chains to provide a flexible communication medium that may overcome some classical problems in supply chain management. This thesis presents the design, development and evaluation of a system which implements a peer-to-peer supply chain system. A general, flexible peer-to-peer network was developed which serves as a foundation to build peer-to-peer data swapping applications on top of. It provides simple network management, searching and data swapping services which form the basis of many peer-to-peer systems. Using the developed framework, a supply chain focussed application was built to test the feasibility of applying peer-to-peer networking to supply chain management. Results and discussion are presented of a scenario analysis which yielded positive results. Several future directions for research in this area are also discussed.
3

How do they understand? Practitioner perceptions of an object-oriented program : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Education (Computer Science) at Massey University, Palmerston North, New Zealand

Thompson, Errol Lindsay January 2008 (has links)
In the computer science community, there is considerable debate about the appropriate sequence for introducing object-oriented concepts to novice programmers. Research into novice programming has struggled to identify the critical aspects that would provide a consistently successful approach to teaching introductory object-oriented programming. Starting from the premise that the conceptions of a task determine the type of output from the task, assisting novice programmers to become aware of what the required output should be, may lay a foundation for improving learning. This study adopted a phenomenographic approach. Thirty one practitioners were interviewed about the ways in which they experience object-oriented programming and categories of description and critical aspects were identified. These critical aspects were then used to examine the spaces of learning provided in twenty introductory textbooks. The study uncovered critical aspects that related to the way that practitioners expressed their understanding of an object-oriented program and the influences on their approach to designing programs. The study of the textbooks revealed a large variability in the cover of these critical aspects.
4

The agile methods : an analytical comparison of five agile methods and an investigation of their target environment : a thesis presented in partial fulfillment of the requirements for the degree of Master of Information Sciences in Information Systems at Massey University, Palmerston North, New Zealand

Strode, Diane Elizabeth Unknown Date (has links)
This study defines the systems development methodologies named agile methods and investigates the environmental conditions where agile methods are most suitable. A definition of agile methods was developed using an analytical comparativeframework to investigate five of the earliest published agile methods; Dynamic SystemsDevelopment Method, Extreme Programming, Scrum, Adaptive Software Development,and Crystal Methods. The framework decomposed each method into its componentparts; philosophy, models, techniques, tools, scope, outputs, practice, and the extent towhich the method may be adapted to a situation. Based on this analysis and a literaturereview, a theoretical model of the target environment for agile methods was developed.This theoretical model is a proposed set of organisation, people, project, technology,and domain factors that relate to the successful use of an agile method.A mixed method research methodology was used. A qualitative design, consisting ofpositivist case studies, was used to test the theoretical model. Data was gathered fromnine software development projects, both agile and non-agile, using questionnaires andinterviews of project leaders. Then cross-case analysis was carried out on each projectfactor in the theoretical model. The relationship between environmental factors andagile method usage was investigated using non-parametric quantitative data analysis.This led to a revised model of the target environment for agile methods. The empiricaldata showed that specific organisational culture factors correlate with effective use of anagile method. These include the organisational characteristics of feedback and learning,teamwork, empowerment of people, collaboration, leadership, loyalty, and a resultsorientedculture that values entrepreneurship, innovation and risk taking.This research is significant for method users, those carrying out empirical research into agile methods, and those carrying out studies of systems development methodologies.
5

A reusable peer-to-peer conversation tool for online second language learning : a thesis presented in partial fulfilment of the requirements for the degree of Master of Information Science in Computer Science at Massey University, Palmerston North, New Zealand

Ye, Jun January 2008 (has links)
To support extramural learning, Johnson (2005) has proposed the Learning Computer concept, which aims to provide a learning appliance that can be used for studying university courses at any time, from anywhere, and by anybody who might have only basic software and hardware, dial-up Internet connection, and little computer literacy. Lonely extramural students need extra support for interactions and collaboration in learning, especially in second language learning that requires intensive oral language practice between the students and the tutor. This research project was a trial to extend IMMEDIATE (the prototype of the Learning Computer) to a second language extramural course. To meet the requirements of long distance conversation in such a course, a synchronous/asynchronous bimodal approach was conceptualised based on a review of e-learning, communication, and VoIP technologies. It was proposed that the prototype should automatically adapt to either synchronous mode or asynchronous mode according to different levels of Internet connection speed. An asynchronous conversation mode similar to Push-to-Talk (PTT) was also proposed. A VoIP SDK was investigated and used in the prototype for fast development. IMMEDIATE messaging protocols have been extended in the prototype to control call procedures and the asynchronous conversation mode. An evaluation of the prototype which was conducted to assess its usability, functionality and integrity of the prototype demonstrated that users can conduct telephone-like synchronous conversation efficiently at high connection speed. Although the PTT-like asynchronous mode has a time lag problem, especially when two users are both at low connection speed, it is a still a good way for novices to practise second language oral skills. The evaluation has given strongly support to the feasibility and effectiveness of the bimodal approach for applying IMMEDIATE in second language extramural learning.
6

Intelligent medical device integration with real time operating system : a thesis submitted to the School of Engineering in partial fulfilment of the requirements for the degree of Master of Engineering, Department of Electronics and Computer Syetem [i.e. Systems] Engineering at Massey University, [Albany], New Zealand

Jan, Zaid January 2009 (has links)
Many commercial devices now being produced have the ability to be remotely monitored and controlled. This thesis aims to develop a generic platform that can easily be extended to interface with many different kinds of devices for remote monitoring and control via a TCP/IP connection. The deployment will be concentrated on Medical devices but can be extended to all serial device interfaces. The hardware to be used in the development of this platform is an ARM Cortex M3 based Micro-Controller board which has to be designed to meet the requirement set by the Precept Health the founder of this platform. The design was conducted at Massey University in collaboration with senior engineer from the company. The main task in achieving the aim was the development of the necessary software layers to implement remote monitoring and control. The eCosCentric real-time embedded operating system was used to form a generic base for developing applications to monitor and control specific devices. The majority of the work involved in this project was the deployment of the operating system to the Micro-Controller. During the development process, several hardware issues were discovered with the Ethernet interface and were corrected. Using the generic platform, an application was developed to allow the reading of Bi-Directional pass through a communication protocol from 4 isolated serial input channels, to an Ethernet channel using TCP protocol.
7

A reusable peer-to-peer conversation tool for online second language learning : a thesis presented in partial fulfilment of the requirements for the degree of Master of Information Science in Computer Science at Massey University, Palmerston North, New Zealand

Ye, Jun January 2008 (has links)
To support extramural learning, Johnson (2005) has proposed the Learning Computer concept, which aims to provide a learning appliance that can be used for studying university courses at any time, from anywhere, and by anybody who might have only basic software and hardware, dial-up Internet connection, and little computer literacy. Lonely extramural students need extra support for interactions and collaboration in learning, especially in second language learning that requires intensive oral language practice between the students and the tutor. This research project was a trial to extend IMMEDIATE (the prototype of the Learning Computer) to a second language extramural course. To meet the requirements of long distance conversation in such a course, a synchronous/asynchronous bimodal approach was conceptualised based on a review of e-learning, communication, and VoIP technologies. It was proposed that the prototype should automatically adapt to either synchronous mode or asynchronous mode according to different levels of Internet connection speed. An asynchronous conversation mode similar to Push-to-Talk (PTT) was also proposed. A VoIP SDK was investigated and used in the prototype for fast development. IMMEDIATE messaging protocols have been extended in the prototype to control call procedures and the asynchronous conversation mode. An evaluation of the prototype which was conducted to assess its usability, functionality and integrity of the prototype demonstrated that users can conduct telephone-like synchronous conversation efficiently at high connection speed. Although the PTT-like asynchronous mode has a time lag problem, especially when two users are both at low connection speed, it is a still a good way for novices to practise second language oral skills. The evaluation has given strongly support to the feasibility and effectiveness of the bimodal approach for applying IMMEDIATE in second language extramural learning.
8

Efficient web-based application development tools on XML-enabled databases : a thesis presented in partial fulfilment of the requirements for the degree of Master of Information Sciences

Chen, Yi January 2008 (has links)
No abstract provided
9

Novel technologies for the manipulation of meshes on the CPU and GPU : a thesis presented in partial fulfilment of the requirements for the degree of Masters of Science in Computer Science at Massey University, Palmerston North, New Zealand

Rountree, Richard John January 2007 (has links)
This thesis relates to research and development in the field of 3D mesh data for computer graphics. A review of existing storage and manipulation techniques for mesh data is given followed by a framework for mesh editing. The proposed framework combines complex mesh editing techniques, automatic level of detail generation and mesh compression for storage. These methods work coherently due to the underlying data structure. The problem of storing and manipulating data for 3D models is a highly researched field. Models are usually represented by sparse mesh data which consists of vertex position information, the connectivity information to generate faces from those vertices, surface normal data and texture coordinate information. This sparse data is sent to the graphics hardware for rendering but must be manipulated on the CPU. The proposed framework is based upon geometry images and is designed to store and manipulate the mesh data entirely on the graphics hardware. By utilizing the highly parallel nature of current graphics hardware and new hardware features, new levels of interactivity with large meshes can be gained. Automatic level of detail rendering can be used to allow models upwards of 2 million polygons to be manipulated in real time while viewing a lower level of detail. Through the use of pixels shaders the high detail is preserved in the surface normals while geometric detail is reduced. A compression scheme is then introduced which utilizes the regular structure of the geometry image to compress the floating point data. A number of existing compression schemes are compared as well as custom bit packing. This is a TIF funded project which is partnered with Unlimited Realities, a Palmerston North software development company. The project was to design a system to create, manipulate and store 3D meshes in a compressed and easy to manipulate manner. The goal is to create the underlying technologies to allow for a 3D modelling system to become integrated into the Umajin engine, not to create a user interface/stand alone modelling program. The Umajin engine is a 3D engine created by Unlimited Realities which has a strong focus on multimedia. More information on the Umajin engine can be found at www.umajin.com. In this project we propose a method which gives the user the ability to model with the high level of detail found in packages aimed at creating offline renders but create models which are designed for real time rendering.
10

Designing CBL systems for complex domains using problem transformation and fuzzy logic : a thesis presented in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Computer Science at Massey University, Palmerston North, New Zealand

Mohanarajah, Selvarajah January 2007 (has links)
Some disciplines are inherently complex and challenging to learn. This research attempts to design an instructional strategy for CBL systems to simplify learning certain complex domains. Firstly, problem transformation, a constructionist instructional technique, is used to promote active learning by encouraging students to construct more complex artefacts based on less complex ones. Scaffolding is used at the initial learning stages to alleviate the difficulty associated with complex transformation processes. The proposed instructional strategy brings various techniques together to enhance the learning experience. A functional prototype is implemented with Object-Z as the exemplar subject. Both objective and subjective evaluations using the prototype indicate that the proposed CBL system has a statistically significant impact on learning a complex domain. CBL systems include Learner models to provide adaptable support tailored to individual learners. Bayesian theory is used in general to manage uncertainty in Learner models. In this research, a fuzzy logic based locally intelligent Learner model is utilized. The fuzzy model is simple to design and implement, and easy to understand and explain, as well as efficient. Bayesian theory is used to complement the fuzzy model. Evaluation shows that the accuracy of the proposed Learner model is statistically significant. Further, opening Learner model reduces uncertainty, and the fuzzy rules are simple and resemble human reasoning processes. Therefore, it is argued that opening a fuzzy Learner model is both easy and effective. Scaffolding requires formative assessments. In this research, a confidence based multiple test marking scheme is proposed as traditional schemes are not suitable for measuring partial knowledge. Subjective evaluation confirms that the proposed schema is effective. Finally, a step-by-step methodology to transform simple UML class diagrams to Object-Z schemas is designed in order to implement problem transformation. This methodology could be extended to implement a semi-automated translation system for UML to Object Models.

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