Improving typography and minimising computation for documents with scalable layouts

Since the 1980s, two paradigms have dominated the representation of formatted electronic documents: flowable and fixed. Flowable formats, such as HTML, EPUB, or those used by word processors, allow documents to scale to any arbitrary page size, but typographical compromises must be made since the layout is computed in real time, and is re-computed each time the document is displayed. Conversely, fixed formats such as SVG or PDF are afforded the potential for arbitrarily complex typography, but are constrained to the fixed layout that is set at the time of creation. With the recent surge in popularity of low-powered portable reading devices -- from tablets to e-readers to mobile phones -- there is an expectation that documents should scale to any size, maintain their high-quality typography, and not provide unnecessary strain on an already overloaded battery. This thesis defines a novel paradigm for electronic document representation -- the Malleable Document -- whereby documents are partially typeset at the time of creation, leaving enough flexibility that their content can be flowed to arbitrary page sizes with minimal computation. One tradeoff encountered is that of increased file size, and this is addressed with a bespoke, computationally-light compression scheme. A sample implementation is presented that transforms documents from a source format into Malleable Document format, alongside a lightweight display engine that enables the documents to be viewed and resized on a wide range of devices, mobile and otherwise. Reviews of the technical aspects and a user study to evaluate the quality of the system's rendering and layout show that the Malleable Document paradigm is a promising alternative to both fixed and flowable formats, and builds upon the best of both approaches

Improving typography and minimising computation for documents with scalable layouts

Since the 1980s, two paradigms have dominated the representation of formatted electronic documents: flowable and fixed. Flowable formats, such as HTML, EPUB, or those used by word processors, allow documents to scale to any arbitrary page size, but typographical compromises must be made since the layout is computed in real time, and is re-computed each time the document is displayed. Conversely, fixed formats such as SVG or PDF are afforded the potential for arbitrarily complex typography, but are constrained to the fixed layout that is set at the time of creation. With the recent surge in popularity of low-powered portable reading devices -- from tablets to e-readers to mobile phones -- there is an expectation that documents should scale to any size, maintain their high-quality typography, and not provide unnecessary strain on an already overloaded battery. This thesis defines a novel paradigm for electronic document representation -- the Malleable Document -- whereby documents are partially typeset at the time of creation, leaving enough flexibility that their content can be flowed to arbitrary page sizes with minimal computation. One tradeoff encountered is that of increased file size, and this is addressed with a bespoke, computationally-light compression scheme. A sample implementation is presented that transforms documents from a source format into Malleable Document format, alongside a lightweight display engine that enables the documents to be viewed and resized on a wide range of devices, mobile and otherwise. Reviews of the technical aspects and a user study to evaluate the quality of the system's rendering and layout show that the Malleable Document paradigm is a promising alternative to both fixed and flowable formats, and builds upon the best of both approaches

Integrating information seeking and information structuring: spatial hypertext as an interface to the digital library.

Information seeking is the task of finding documents that satisfy the information needs of a person or organisation. Digital Libraries are one means of providing documents to meet the information needs of their users - i.e. as a resource to support information seeking. Therefore, research into the activity of information seeking is key to the development and understanding of digital libraries. Information structuring is the activity of organising documents found in the process of information seeking. Information structuring can be seen as either part of information seeking, or as a sepárate, complementary activity. It is a task performed by the seeker themselves and targeted by them to support their understanding and the management of later seeking activity. Though information structuring is an important task, it receives sparse support in current digital library Systems. Spatial hypertexts are computer software Systems that have been specifically been developed to support information structuring. However, they seldom are connected to Systems that support information seeking. Thus to day, the two inter-related activities of information seeking and information structuring have been supported by disjoint computer Systems. However, a variety of research strongly indicates that in physical environments, information seeking and information structuring are closely inter-related activities. Given this connection, this thesis explores whether a similar relationship can be found in electronic information seeking environments. However, given the absence of a software system that supports both activities well, there is an immédiate practical problem. In this thesis, I introduce an integrated information seeking and structuring System, called Garnet, that provides a spatial hypertext interface that also supports information seeking in a digital library. The opportunity of supporting information seeking by the artefacts of information structuring is explored in the Garnet system, drawing on the benefits previously found in supporting one information seeking activity with the artefacts of another. Garnet and its use are studied in a qualitative user study that results in the comparison of user behaviour in a combined electronic environment with previous studies in physical environments. The response of participants to using Garnet is reported, particularly regarding their perceptions of the combined system and the quality of the interaction. Finally, the potential value of the artefacts of information structuring to support information seeking is also evaluated

An aesthetics of touch: investigating the language of design relating to form

How well can designers communicate qualities of touch? This paper presents evidence that they have some capability to do so, much of which appears to have been learned, but at present make limited use of such language. Interviews with graduate designer-makers suggest that they are aware of and value the importance of touch and materiality in their work, but lack a vocabulary to fully relate to their detailed explanations of other aspects such as their intent or selection of materials. We believe that more attention should be paid to the verbal dialogue that happens in the design process, particularly as other researchers show that even making-based learning also has a strong verbal element to it. However, verbal language alone does not appear to be adequate for a comprehensive language of touch. Graduate designers-makers’ descriptive practices combined non-verbal manipulation within verbal accounts. We thus argue that haptic vocabularies do not simply describe material qualities, but rather are situated competences that physically demonstrate the presence of haptic qualities. Such competencies are more important than groups of verbal vocabularies in isolation. Design support for developing and extending haptic competences must take this wide range of considerations into account to comprehensively improve designers’ capabilities

Online learning on the programmable dataplane

This thesis makes the case for managing computer networks with datadriven methods automated statistical inference and control based on measurement data and runtime observations—and argues for their tight integration with programmable dataplane hardware to make management decisions faster and from more precise data. Optimisation, defence, and measurement of networked infrastructure are each challenging tasks in their own right, which are currently dominated by the use of hand-crafted heuristic methods. These become harder to reason about and deploy as networks scale in rates and number of forwarding elements, but their design requires expert knowledge and care around unexpected protocol interactions. This makes tailored, per-deployment or -workload solutions infeasible to develop. Recent advances in machine learning offer capable function approximation and closed-loop control which suit many of these tasks. New, programmable dataplane hardware enables more agility in the network— runtime reprogrammability, precise traffic measurement, and low latency on-path processing. The synthesis of these two developments allows complex decisions to be made on previously unusable state, and made quicker by offloading inference to the network. To justify this argument, I advance the state of the art in data-driven defence of networks, novel dataplane-friendly online reinforcement learning algorithms, and in-network data reduction to allow classification of switchscale data. Each requires co-design aware of the network, and of the failure modes of systems and carried traffic. To make online learning possible in the dataplane, I use fixed-point arithmetic and modify classical (non-neural) approaches to take advantage of the SmartNIC compute model and make use of rich device local state. I show that data-driven solutions still require great care to correctly design, but with the right domain expertise they can improve on pathological cases in DDoS defence, such as protecting legitimate UDP traffic. In-network aggregation to histograms is shown to enable accurate classification from fine temporal effects, and allows hosts to scale such classification to far larger flow counts and traffic volume. Moving reinforcement learning to the dataplane is shown to offer substantial benefits to stateaction latency and online learning throughput versus host machines; allowing policies to react faster to fine-grained network events. The dataplane environment is key in making reactive online learning feasible—to port further algorithms and learnt functions, I collate and analyse the strengths of current and future hardware designs, as well as individual algorithms

Visualising software in cyberspace

The problems of maintaining software systems are well documented. The increasing size and complexity of modern software serves only to worsen matters. Software maintainers are typically confronted with very large and very complex software systems, of which they may have little or no prior knowledge. At this stage they will normally have some maintenance task to perform, though possibly little indication of where or how to start. They need to investigate and understand the software to some extent in order to begin maintenance. This understanding process is termed program comprehension. There are various theories on program comprehension, many of which put emphasis on the construction of a mental model of the software within the mind of the maintainor. These same theories hypothesise a number of techniques employed by the maintainer for the creation and revision of this mental model. Software visualisation attempts to provide tool support for generating, supplementing and verifying the maintainer’s mental model. The majority of software visualisations to date have concentrated on producing two dimensional representations and animations of various aspects of a software system. Very little work has been performed previously regarding the issues involved in visualising software within a virtual reality environment. This research represents a significant first step into this exciting field and offers insight into the problems posed by this new media. This thesis provides an identification of the possibilities afforded byU3D graphics for software visualisation and program comprehension. It begins by defining seven key areas of 3D software visualisation, followed by the definition of two terms, visualisation and representation. These two terms provide a conceptual division between a visualisation and the elements of which it is comprised. This division enables improved discussion of the properties of a 3D visualisation and particularly the idenfification of properties that are desirable for a successful visualisation. A number of such desirable properties are suggested for both visualisations and representations, providing support for the design and evaluation of a 3D software visualisation system. Also presented are a number of prototype visualisations, each providing a different approach to the visualisation of a software system. The prototypes help demonstrate the practicalities and feasibility of 3D software visualisation. Evaluation of these prototypes is performed using a variety of techniques, the results of which emphasise the fact that there is substantial potential for the application of 3D graphics and virtual reality to software visualisation

Realistic electronic books

People like books. They are convenient and can be accessed easily and enjoyably. In contrast, many view the experience of accessing and exploring electronic documents as dull, cumbersome and disorientating. This thesis claims that modelling digital documents as physical books can significantly improve reading performance. To investigate this claim, a realistic electronic book model was developed and evaluated. In this model, a range of properties associated with physical books---analogue page turning, bookmarks and annotations---are emulated. Advantage is also taken of the digital environment by supporting hyperlinks, multimedia, full-text search over terms and synonyms, automatically cross referencing documents with an online encyclopaedia, and producing a back-of-the-book index. The main technical challenge of simulating physical books is finding a suitable technique for page turning that is sufficiently realistic, yet lightweight, responsive, scalable and accessible. Several techniques were surveyed, implemented and evaluated. The chosen technique allows realistic books to be presented in the Adobe Flash Player, the most widely used browser plug-in on the Web. A series of usability studies were conducted to compare reading performance while performing various tasks with HTML, PDF, physical books, and simulated books. They revealed that participants not only preferred the new interface, but completed the tasks more efficiently, without any loss in accuracy

Open Data and Models for Energy and Environment

This Special Issue aims at providing recent advancements on open data and models. Energy and environment are the fields of application.For all the aforementioned reasons, we encourage researchers and professionals to share their original works. Topics of primary interest include, but are not limited to:Open data and models for energy sustainability;Open data science and environment applications;Open science and open governance for Sustainable Development Goals;Key performance indicators of data-aware energy modelling, planning and policy;Energy, water and sustainability database for building, district and regional systems; andBest practices and case studies

Runtime visualisation of object-oriented software

Software is a complex and invisible entity, yet one which is core to modem life. The development and maintenance of such software includes one staple task, the need to understand the software at the implementation level. This process of program comprehension is difficult and time consuming. Yet, despite its importance, there remains very limited tool support for program comprehension activities. The results of this research show the role that runtime visualisation can play in aiding the comprehension of object-oriented software by highlighting both its static and dynamic structure. Previous work in this area is discussed, both in terms of the representations used and the methods of extracting runtime information. Building on this previous work, this thesis develops new representations of object-oriented software at runtime, which are then implemented in a proof of concept tool. This tool allowed the representations to be investigated on real software systems. The representations are evaluated against two feature-based evaluation frameworks. The evaluation focuses on generic software visualisation criteria, due to the lack of any specific frameworks for visualising dynamic information. The evaluation also includes lessons learnt in the implementation of a prototype visualisation tool. The object-oriented paradigm continues to grow in popularity and provides advantages to program comprehension activities. However, it also brings a number of new challenges to program comprehension due to the discrepancies between its static definition and its runtime structure. Therefore, techniques that highlight both the static definition and the runtime behaviour of object-oriented systems offer benefits to their comprehension. Software visualisation offers an approach to aid program comprehension activities through providing a means to deal with the size and complexity of the software and its invisible nature. This thesis highlights the generic issues that software visualisation faces, before focusing on how the visualisation of runtime information affects these issues. Many of the issues are compounded by the dynamic nature of the information to be visualised and the explosive growth in the volume of information that this dynamism can bring. Wider results of this research have allowed the proposal of the necessary concepts that should be considered in the design and evaluation of runtime visualisations. Software visualisation at runtime is still a relatively unexplored area and there remains many research challenges within it. This thesis aims to act as a first step to addressing these challenges and aims to promote interest and future development within this area