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INTECoM : an integrated conceptual data modelling framework : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Information Systems at Massey University, Palmerston North, New Zealand
(Massey University, 2000) Atkins, Clare Frances
Conceptual data models, a fundamental component of information systems development, traditionally play two essential roles, as communication tools and database design blueprints. However, despite their importance to the success of information systems, and a considerable amount of research effort, no definitive method for constructing them has yet been described. Entity-Relationship (E-R) Modelling, accepted as a de facto standard for a number of years, has been increasingly criticised. A number of alternatives have been proposed and some, such as Object-Oriented modelling, have gradually been accepted by the practitioner community. Nevertheless, effective conceptual data modelling continues to be recognised as a difficult activity, both to teach and to practice. This study investigates conceptual data modelling in the context of the relational database development process. However, rather than specifying a new method or exploring the efficacy of existing ones, it focuses on the nature of the activity itself. The construction of a conceptual data model encompasses both the analysis and design stages of systems development. Some fundamental differences in modeller behaviour, required by these activities, are explored. The disparate purposes of a conceptual data model are also investigated and the effectiveness of using the same modelling method in both stages, and for both purposes, is questioned. To explore the suitability of current methods to specific development activities, the procedures inherent in the use of two conceptual data modelling approaches, E-R Modelling and the Natural Language Information Analysis Method (NIAM) are also investigated. The result of this exploration is the recognition that the methods have exclusive strengths and that it is more productive to view them as complementary rather than competing. Consequently, a database design framework, INTECoM, is constructed in which the two methods are integrated and matched to the activities for which they are most suited. The framework is supplemented by a new technique, NaLER, to facilitate communication in the design stage. The soundness and viability of this theoretical framework is examined through its use on a small development and the implications of the adoption of INTECoM on both education and practice are considered.
The effects of using problem knowledge in a neural network for image processing tasks : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Computer Science at Massey University, Palmerston North, New Zealand
(Massey University, 2001) Gunetileke, Kapila Sanjeeva
This thesis is concerned with aspects of computational intelligence. Computational intelligence is a new paradigm of artificial intelligence based on biological intelligence. Computational Intelligence explores the potential for biologically inspired intelligent adaptive machines and behavior. A relatively new and important sub discipline within the field of computational intelligence, is that of neural networks. Neural networks are networks of artificial neurons with a high degree of interconnectivity. The networks capture and accumulate knowledge as the pattern of weights in the interconnections between neurons. Neural networks are iteratively trained to perform tasks by "learning" from examples. These networks are often slow to train. One of the reasons for this is that the starting weights of the network are conventionally not related to the problem being solved. In this thesis a methodology is explored that maps problem knowledge to the starting weights of a fuzzy neural network window filter (FuNNWF). The FuNNWF architecture was developed from the combination of fuzzy logic and artificial neural networks for image processing tasks. The effects of the use of problem knowledge on FuNNWF training are investigated. The problem knowledge mapping procedure is extended from boolean rule mapping to conditional rule mapping, which allows better representation of the problems. Four real world image processing problems are investigated using the new weight initialization methodology. The experiments reported in this thesis demonstrate that the use of problem knowledge improves the robustness and convergence of the neural network. It is also shown that the use of the methodology is most effective on network training when the training data is noisy, unreliable and ambiguous.
Subset selection routing : modelling and heuristics : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Operations Research at Massey University
(Massey University, 2002) Beale, Ian R.
This theoretically practical thesis relates to the field of subset selection routing problems, in which there are a set of customers available to be serviced and decisions of which customers to service and how to carry out the service are required. We develop models for problems of this kind, particularly accounting for customer service in decision making. We consider possibilities that relate to not servicing customers, or servicing them poorly with respect to their desired service, and we model some possible implications of these decisions. We consider different constraints that may appear within these problems and exploit these within an overall model for a problem which we term the Maximum Collection Problem. We develop effective, generic solution methods for these problems and tailor specific routines to certain types of problem. We devise new methods for generating problems with specific characteristics and we use these to test the effectiveness of our methods. We extensively test our methods, identify shortcomings of existing methods and develop new methods for overcoming the identified weaknesses of the methods. We introduce a new version of subset selection routing problems, involving decision making in dynamic situations. We create models involving next day and same day service and develop fast, practical methods for obtaining effective solutions to these problems and test their effectiveness and robustness on a number of varied test problems.
The integration of task and dialogue modelling in the early stages of user interface design : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Computer Science at Massey University, Palmerston North, New Zealand
(Massey University, 2003) Scogings, Christopher John
In the early stages of the design of graphical user interfaces, models and notations are required for describing user tasks and for describing the structure of the human-computer dialogue to support these tasks. These descriptions should ideally be linked, but in practice task modelling and dialogue modelling are conducted in isolation with differing notations. The research reported in this thesis reviews both task and dialogue modelling and describes how the divide between the two can be bridged via the Lean Cuisine+ notation. Lean Cuisine+ was developed as a semi-formal graphical notation for describing the underlying behaviour of direct manipulation user interfaces (Phillips, 1995). The notation has a significant advantage over other dialogue modelling notations in that it can represent task sequences within the context of the dialogue structure and hence bring dialogue modelling and task modelling together. The research describes how Lean Cuisine+ has been analysed and modified in order to simplify it and to make it more suitable for use with a supporting software tool. There exists a significant gap between user interface design and the design of entire software applications. This is true even for the latest software engineering notation, UML, which has become the de facto industry standard. The thesis reviews UML and reveals its shortcomings regarding support for user interface design. The research suggests a solution for the problem by proposing a method for the early stages of user interface design that uses Lean Cuisine+, in order to combine both task and dialogue modelling, and is constructed to form an integral part of the overall software design process advocated by the authors of UML. The method is applied to two case studies. A prototype Software Environment for Lean Cuisine+ with UML (SELCU) has been developed to enable the construction, storage, editing and printing of Lean Cuisine+ specifications, and to partially support the method. The thesis describes the design, implementation and use of this software support environment. Finally, preliminary work by the author on the automatic generation of Lean Cuisine+ specifications is reported. This shows promise, and has been further developed recently in associated masters-level research in which extensions to SELCU have been implemented.
A process approach for understanding strategic enterprise system implementation decisions : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Information Systems at Massey University, Albany Campus, New Zealand
(Massey University, 2004) Shakir, Maha
Enterprise system (ES) implementation involves large investment of resources for a long period of time before business benefits can be realized, meaning the choice of system is one of the most critical decisions an organization makes. However, a right choice does not guarantee a successful working system because ES implementation is a complex and a dynamic process that involves a mix of technological and organizational decisions. These decisions cannot be structured and need to be revised and reformulated with the pace of implementation. As a result, the understanding of these decisions cannot be separated from the understanding of the implementation process. A review of the IS literature suggests that the dominant stream of strategic decision making (SDM) research follows a strategy formulation approach, while research into implementation of strategic IT decisions receives little attention. To fill this gap, this study takes the latter approach both to understand 15 key ES implementation decisions, and to establish a model for facilitating ES implementation that has both a theoretical and a practical significance. Using the multiple theoretical perspectives of SDM models and through two case studies of ES implementation, qualitative data on the SDM process pertaining to the 15 decisions was gathered to inductively develop a model of the ES implementation process as it unfolded over time. The SDM model reveals ES implementation as a four-phase process: (1) preparation, (2) design, (3) configuration, and (4) realization. For each phase of the model, key activities pertaining to the decision process for these 15 decisions that enabled implementation to move forward are described. Key words: Enterprise system (ES), enterprise resource planning (ERP), strategic decision-making (SDM), decisions models, process approach, case studies
Compressing DNA sequence databases with coil
(BioMed Central, 2008-05-20) White, W. Timothy J.; Hendy, Michael D.
Background: Publicly available DNA sequence databases such as GenBank are large, and are growing at an exponential rate. The sheer volume of data being dealt with presents serious storage and data communications problems. Currently, sequence data is usually kept in large "flat files," which are then compressed using standard Lempel-Ziv (gzip) compression – an approach which rarely achieves good compression ratios. While much research has been done on compressing individual DNA sequences, surprisingly little has focused on the compression of entire databases of such sequences. In this study we introduce the sequence database compression software coil. Results: We have designed and implemented a portable software package, coil, for compressing and decompressing DNA sequence databases based on the idea of edit-tree coding. coil is geared towards achieving high compression ratios at the expense of execution time and memory usage during compression – the compression time represents a "one-off investment" whose cost is quickly amortised if the resulting compressed file is transmitted many times. Decompression requires little memory and is extremely fast. We demonstrate a 5% improvement in compression ratio over state-of-the-art general-purpose compression tools for a large GenBank database file containing Expressed Sequence Tag (EST) data. Finally, coil can efficiently encode incremental additions to a sequence database. Conclusion: coil presents a compelling alternative to conventional compression of flat files for the storage and distribution of DNA sequence databases having a narrow distribution of sequence lengths, such as EST data. Increasing compression levels for databases having a wide distribution of sequence lengths is a direction for future work.
LineageSpecificSeqgen: generating sequence data with lineage-specific variation in the proportion of variable sites
(Biomed Central, 2008-11-21) Grievink, Liat Shavit; Penny, David; Hendy, Mike D; Holland, Barbara R
Background: Commonly used phylogenetic models assume a homogeneous evolutionary process throughout the tree. It is known that these homogeneous models are often too simplistic, and that with time some properties of the evolutionary process can change (due to selection or drift). In particular, as constraints on sequences evolve, the proportion of variable sites can vary between lineages. This affects the ability of phylogenetic methods to correctly estimate phylogenetic trees, especially for long timescales. To date there is no phylogenetic model that allows for change in the proportion of variable sites, and the degree to which this affects phylogenetic reconstruction is unknown. Results: We present LineageSpecificSeqgen, an extension to the seq-gen program that allows generation of sequences with both changes in the proportion of variable sites and changes in the rate at which sites switch between being variable and invariable. In contrast to seq-gen and its derivatives to date, we interpret branch lengths as the mean number of substitutions per variable site, as opposed to the mean number of substitutions per site (which is averaged over all sites, including invariable sites). This allows specification of the substitution rates of variable sites, independently of the proportion of invariable sites. Conclusion: LineageSpecificSeqgen allows simulation of DNA and amino acid sequence alignments under a lineage-specific evolutionary process. The program can be used to test current models of evolution on sequences that have undergone lineage-specific evolution. It facilitates the development of both new methods to identify such processes in real data, and means to account for such processes. The program is available at: http://awcmee.massey.ac.nz/downloads.htm.
Real-time adaptive noise cancellation for automatic speech recognition in a car environment : a thesis presented in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Computer Engineering at Massey University, School of Engineering and Advanced Technology, Auckland, New Zealand
(Massey University, 2008) Qi, Ziming
This research is mainly concerned with a robust method for improving the performance of a real-time speech enhancement and noise cancellation for Automatic Speech Recognition (ASR) in a real-time environment. Therefore, the thesis titled, “Real-time adaptive beamformer for Automatic speech Recognition in a car environment” presents an application technique of a beamforming method and Automatic Speech Recognition (ASR) method. In this thesis, a novel solution is presented to the question as below, namely: How can the driver’s voice control the car using ASR? The solution in this thesis is an ASR using a hybrid system with acoustic beamforming Voice Activity Detector (VAD) and an Adaptive Wiener Filter. The beamforming approach is based on a fundamental theory of normalized least-mean squares (NLMS) to improve Signal to Noise Ratio (SNR). The microphone has been implemented with a Voice Activity Detector (VAD) which uses time-delay estimation together with magnitude-squared coherence (MSC). An experiment clearly shows the ability of the composite system to reduce noise outside of a defined active zone. In real-time environments a speech recognition system in a car has to receive the driver’s voice only whilst suppressing background noise e.g. voice from radio. Therefore, this research presents a hybrid real-time adaptive filter which operates within a geometrical zone defined around the head of the desired speaker. Any sound outside of this zone is considered to be noise and suppressed. As this defined geometrical zone is small, it is assumed that only driver's speech is incoming from this zone. The technique uses three microphones to define a geometric based voice-activity detector (VAD) to cancel the unwanted speech coming from outside of the zone. In the case of a sole unwanted speech incoming from outside of a desired zone, this speech is muted at the output of the hybrid noise canceller. In case of an unwanted speech and a desired speech are incoming at the same time, the proposed VAD fails to identify the unwanted speech or desired speech. In such a situation an adaptive Wiener filter is switched on for noise reduction, where the SNR is improved by as much as 28dB. In order to identify the signal quality of the filtered signal from Wiener filter, a template matching speech recognition system that uses a Wiener filter is designed for testing. In this thesis, a commercial speech recognition system is also applied to test the proposed beamforming based noise cancellation and the adaptive Wiener filter.
Learning about user interface design through the use of user interface pattern languages : a thesis dissertation presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Computer Science at Massey University, New Zealand
(Massey University, 2010) Todd, Elisabeth-Ann Gynn
The focus of this research is to investigate the potential of user interface (UI) pattern languages in assisting students of Human Computer Interaction (HCI) to learn the principles of UI design. A graphical representation named a UI-pattern model was developed. It arose from the evaluation of four existing pattern languages. The UI-pattern model is an enhanced form of UI pattern list that represents a specific UI. It was recognised that the UI-pattern model has the potential to help students learn about pattern language structure. It was also realised that UI-pattern modelling can be used to incrementally improve pattern languages through the generative process proposed by Alexander (1979). A UI pattern language Maturity Model (UMM) has been developed. This model can be used by educators when selecting and/or modifying existing UI pattern languages so that they are more appropriate for student use. A method for developing detailed UI designs that utilises a UI pattern language has been developed with the aim of providing students with an ‘authentic’ real-world UI design experience, as envisaged by constructivist educational theory (Jonassen 1999). This UI design method (TUIPL) guides the students’ development of user interface conceptual models. To establish the authenticity of TUIPL three case studies were undertaken out with developers who had differing levels of UI design experience. A series of studies investigated how HCI students used TUIPL to guide the development of UI-pattern models and canonical abstract prototypes. The studies also ascertained the students’ views on using three different forms of UI pattern (illustrated, narrative and diagrammed). Data was collected by observation, questionnaires and completed exercises. The results indicate that the students developed an understanding of pattern language structure, were positive about their experience building UI-pattern models and canonical abstract prototypes, and that patterns aided communication. The learning outcomes were encouraging and students responded positively to using a UI pattern language.
CASTLE : a computer-assisted sentence stress teaching and learning environment : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Computer Science at Massey University, Manawatu, New Zealand
(Massey University, 2010) Lu, Jingli
A Computer-Assisted sentence Stress Teaching and Learning Environment (CASTLE) is proposed and developed, in order to help learners of English as a Second Language (ESL) to perceive and produce English stress correctly. Sentence stress plays an important role in English verbal communication. Incorrect stress may confuse listeners, and even break down a conversation. Stress is also challenging for ESL learners to master. It is neither easy for them to produce nor easy to perceive stress. Learners tend to transfer the stress patterns of their first language into English, which is not always appropriate. However, stress has been overlooked in English language teaching classes, due to the time limits of a class and teachers’ lack of confidence of teaching stress. Thus, CASTLE is intended to help ESL learners to use sentence stress correctly. There are three modules in CASTLE: an individualised speech learning material providing module, a perception assistance module and a production assistance module. Through conducting an investigation into which voice features (i.e. gender, pitch and speech rate) makes a teacher’s voice preferable for learners to imitate, we find that learners’ imitation preferences vary, according to many factors (e.g. English background and language proficiency). Thus, the speech material providing module of CASTLE can provide individualised speech material for different learners, based on their preferred voice features. In the perception assistance module of CASTLE, we propose a set of stress exaggeration methods that can automatically enlarge the differences between stressed and unstressed syllables in teachers’ voice. These stress exaggeration methods are implemented by the manipulation of different prosodic features (i.e. pitch, duration and intensity) of the teachers’ voice. Our experimental results show that all our proposed exaggeration methods could help ESL learners to perceive sentence stress more accurately. In the production assistance module of CASTLE, we propose a clapping-based sentence stress practice model that is intended to help ESL learners to be aware of the rhythm of English language. By analysing the limitation of conventional categorical representation of stress, we propose a fuzzy representation which is intended to better represent the subjective nature of stress. Based on the fuzzy representation of stress, we propose three feedback models in order to help the learners correct their stress errors. In addition to the development of CASTLE, we also propose an enhanced fuzzy linear regression model which can overcome the spreads increasing problem encountered by previous fuzzy linear regression models.

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