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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.
41

Proximal anthropomorphised interfaces for networked multimedia services

Parker, L. M. January 2000 (has links)
Computers are becoming an ever increasing part of our daily lives both at work and at home. This has led researchers to investigate humanised interfaces as an attempt to provide naive users access to information technology. A natural aspect of humanised interfaces is the incorporation of anthropomorphised entities that can act as agents (personae) on behalf of users. Although considerable work has been carried out on many aspects of computer generated personae research tools in this area are scarce and there have been few attempts to approach the concept of an anthropomorphised interface as a whole rather than as a persona addition to standard work packages. This thesis analyses past work and identifies key requirements for future personae interfaces. It then goes on to present a novel approach to producing a unified persona interface that incorporates many of the disparate capabilities of earlier approaches. This novel approach is then tested objectively and subjectively before being used to undertake a series of experiments both on site in the University of Edinburgh and at sites across Europe in order to identify constraints and bounds for personae interfaces. The results from these experiments are statistically analysed and conclusions are drawn that form a kernel set of constraints for persona interaction. A method for automating the application of this kernel set of constraints is provided and an initial foray into intelligent persona dialogue control is presented. Final conclusions from this work are presented and relevant future work is described.
42

Electronic Nose Optimisation

Scott, Simon Michael January 2005 (has links)
No description available.
43

Dynamism of networks : a case study of the peer-to-peer Gnutella network

Khanna, Ashutosh Prabhat Kumar January 2007 (has links)
No description available.
44

The integration of architectural design and energy modelling software

Hetherington, Robina January 2013 (has links)
Intelligent and integrated architectural design can substantially reduce carbon dioxide emissions from energy used in buildings. However, architects need new tools to help them to design enjoyable, comfortable, attractive and yet technically rigorous, low energy buildings. This thesis investigates, by means of a Research Through Design approach, how architectural software could be better designed to fulfil this need by the integration of design, energy simulation and decision support systems. The problem domain of the design of buildings with very low energy requirements was analysed. Two case studies were employed to investigate the limitations with current software. User and domain software requirements were recorded and analysed. Conflicting requirements were noted, in particular, dichotomous views of the building model. An investigation was carried out into the different interoperable standards that result in these views and rules on how to compose the building model as a series of Intelligent Spaces proposed. The Intelligent Spaces would be abstract volumes, enclosed by zero thickness surfaces, which have data and rules attached. Early prototyping of integrated software was carried out by means of a series of sketches and diagrammatic examples. The novel feature of the proposal is that it maintains both an abstract and detailed version of the building model through all stages of the building design and use. Key features of the proposed software are: 1) the ability to move iteratively between sketch to detailed design to explore different approaches to the building form and construction, 2) the setting and monitoring of relevant energy targets throughout the different building design stages and 3) the integration of an advisory system linked to energy targets to support decision making. This space based approach to the software has the potential to provide a ‘designerly’ front to the sophisticated processes of a Building Information Modelling environment.
45

Hardware Acceleration of Network Intrusion Detection System Using FPGA

Hashmi, Adeel January 2011 (has links)
No description available.
46

The development of three-dimensional Computer Aided Design (CAD) modelling strategies and an investigation into their impact on novice users

Allsop, Clare January 2009 (has links)
Computer Aided Design (CAD) is a tremendously powerful tool within the design industry, yet when used inappropriately, can be a hindrance to product designers. Employing ineffective CAD modelling strategies (CMS) can lead to increased project costs as a result of an unnecessary amount of time being spent making design changes to the product. However, when CMS are implemented effectively, it has been shown that novice CAD users can not only create an accurate three-dimensional (3D) representation of a product, but are able to make key design changes quickly and effectively (a skill often associated with practiced CAD users). The submission detailed herein documents the development of 3D CAD modelling strategies and the investigation into their impact on novice users. The submission has been split into eleven chapters. The subject is introduced in Chapter One, where the background and structure of the research is considered, as well as the implications of lack of CAD experience for novice CAD users. Some initial research aims were generated, which are examined in the Exploratory Study detailed in Chapter Two. This includes an exploratory review of literature together with details of the initial studies involving CAD users, where it was found that there were potential benefits of communicating CMS to novice CAD users. Having examined the prior art in the field, a theme emerges regarding the benefits of communicating CMS to product designers and focused research aims are presented. The research methodology is considered in Chapter Three, which outlines the databases built to manage the periodic review of literature, to ensure that methodologies were in place to draw meaningful results from the data, both qualitative and quantitative. The pilot study, used to understand how designers implemented strategies when modelling on CAD is discussed in Chapter Four, which lead to the definition of the content of the CAD Modelling Strategies Support (CMSS) material in Chapter Five. Following this, a systematic review of literature on the subject of teaching and learning is discussed in Chapter Six, including pedagogical issues such as the Experiential Learning Theory and visualisation, where a blended learning approach was identified as being the most appropriate method with which to present the CMSS material. The CMSS material was then piloted a number of times within the Pilot Study Two phase detailed in Chapter Seven. The final CMSS material is then outlined in Chapter Eight, which was later evaluated against the emergent theme, as documented in Chapter Nine. The discussion continues in Chapter Ten where it was found that the participants exposed to the CMSS material had used a more effective strategy to model a product on CAD than those who did not use the material (the Control Group). This resulted in them being able to make key design changes to their models in approximately half the time of the Control Group. It was found that the CMSS material produced competent CAD users who could easily make design changes to their models, which inferred implications on the teaching and learning of CAD. Overall conclusions and recommendations relating to the research are drawn in Chapter Eleven that, again, bear direct relevance to how product designers learn to use CAD.
47

Studies of some feedback control mechanisms in operating systems

Alderson, Albert January 1974 (has links)
The possibility of enhancing the effectiveness of an operating system by the introduction of appropriate feedback controls is explored by examining some resource allocation problems. The allocation of and I/O processors in a multiprogramming core, CPU demand paging environment is studied in terms of feedback control. A major part of this study is devoted to the application of feedback control concepts to core allocation to prevent thrashing and develop algorithms of practical value. To aid this study a simulator is developed which uses probability distributions to represent program behaviour. Successful algorithms are developed employing a two stage page replacement function which selects a process from which a page is then chosen to be replaced. Improving the performance of these algorithms by using a 'drain process' to aid the dynamic determination of the current locality of a process is also discussed. The complexity of the overall resource allocation problem is dealt with by employing a hierarchy of individual resource allocation policies. These control scheduling, core allocation and dispatching. By considering the levels of the hierarchy as separate feedback control systems the restrictions which must be placed upon the individual levels are derived. The extension of these results to further levels is also discussed.
48

Computer representation of graphical information with applications

Harrison, E. S. January 1971 (has links)
The research work contained in this thesls lies mainly in the field of computer graphics. The initial chapters are concerned with methods of representing three dimensional solids in two dimensions. Chapter 2 describes a method by which points in three dimensions can be projected onto a two dimensional plane of This is an essential requirement in the projection. This is an essential requirement in the representation of three dimensional solids. Chapter 3 describes a method by which convex polyhedra can be represented by computer. Both the hidden polyhedra and visible face of the polyhedron can be represented by computer. Having tackled this problem, the more difficult problem of representing the non convex polyhedron has been attempted and the results of this work are presented in Chapter 4. Line drawings of the various polyhedra, produced on a graph plotter, are given as examples at the end of Chapters 2, 3 and 4. The problem of how to connect a given line drawing such that the distance travelled by the pen of some computer display is kept to a minimum is discussed in Chapter 5 and various definitions of the concepts involved are given. Theory associated with this 'Pen-Up Problem' has been developed and is explained in detail in the early part of Chapter 6. A method of obtaining an optimal solution to the problem is presented in the latter part of this chapter in addition to various enumerative schemes which have been developed to obtain good feasible solutions to the pen up problems under various conditions Extensive C.P.U. timing experiments have been carried out in Chapter 7 on the various enumerative schemes in Chapter 6 and it has introduced been possible to reach conclusions on the applicability of the various methods. Several topics of interest which have arisen during the main research work are presented as appendices. The programs which have been coded during the period of research are also inc1udeu as appendices.
49

Performance measurement and analysis of large filestores

Jones, David Alan January 1978 (has links)
Performance measurements of two large time-sharing computer systems are presented, with emphasis on their disk filestores. Similarities of process behaviour are found in the measured systems and another system reported in the literature. Individual processes make i/o requests in sequences, or bursts. Burst lengths have a mean of two with a large variance; within a burst, file i/o requests are spatially sequential in intent and are temporally related. Characterizations of these behaviour patterns form the basis of a methodology for filestore evaluation and design. Descriptions of spatial and temporal load are abstracted from software traces without loss of any performance factor; these descriptions are inputs to a statistical model of the processes in the environment of the filestore. The filestore is represented by a simulation queuing model. The method specifies the inputs to the composite model and describes the calibration of outputs to match observable outputs. A model is built by this method, and validated for different loads. The model is used for three evaluation experiments. Disk request scheduling is not statistically significant; filestore layout and disk capacity are highly significant; disks with fast-access areas are shown to improve performance by taking advantage of spatial accessing patterns. The limits of performance of a novel filestore equipped with a cache store are explored to determine guidelines for this new design. Modest improvements resulting from this design are shown to produce a considerable improvement in overall system performance.
50

Congestion problems in computing systems

Mitrani, I. January 1972 (has links)
The subject of this dissertation is the modeling and analysis of multiprogramming computing systems. Several cyclic queuing models are studied. The systems which they apl)roximate have one central processor and one or more peripheral processors; queues are served in order of arrival or accordlng to priority disciplines. Except in the simplont case of 'one central and one peripheral processor, FIFO queuing and exponential service times at both processors t, all models are e.nalysed in the steady-state. Expressions for the central processor utilisation factor, the rate of departures from the system, the average reSidence time and, in the case mentioned above, the Laplace tranf:1forms of the interarrival interval and of the resldence time are obtained.

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