Joseph Reddington

Automatically generating stories from sensor data

Recent research in Augmented and Alternative Communication (AAC) has begun to make use of Natural Language Generation (NLG) techniques. This creates an opportunity for constructing stories from sensor data, akin to existing work in life-logging. This paper examines the potential of using NLG to merge the AAC and life-logging domains. It proposes a four stage hierarchy that categorises levels of complexity of output text. It formulates a key subproblem of clustering sensor data into narrative events and describes three potential approaches for resolving this subproblem.

Looking at clouds from both sides: The advantages and disadvantages of placing personal narratives in the cloud

This article explores the nature of cloud computing in the context of processing sensitive personal data as part of a personal narrative. In so doing, it identifies general security concerns about cloud computing and presents examples of cloud technologies used to process such data. The use of personal narratives in electronic patient records and in voice output communication aids is compared and contrasted and the implications of the advent of cloud computing for these two scenarios are considered.

Algorithms for generating convex sets in acyclic digraphs

A set X of vertices of an acyclic digraph D is convex if X ? ? and there is no directed path between vertices of X which contains a vertex not in X. A set X is connected if X ? ? and the underlying undirected graph of the subgraph of D induced by X is connected. Connected convex sets and convex sets of acyclic digraphs are of interest in the area of modern embedded processor technology. We construct an algorithm A for enumeration of all connected convex sets of an acyclic digraph D of order n. The time complexity of A is O ( n ? cc ( D ) ) , where cc ( D ) is the number of connected convex sets in D. We also give an optimal algorithm for enumeration of all (not just connected) convex sets of an acyclic digraph D of order n. In computational experiments we demonstrate that our algorithms outperform the best algorithms in the literature.

Better Than Optimal: Fast Identification of Custom Instruction Candidates

Asymptotically optimal algorithms do not always yield the fastest practical algorithm on realistic cases. We examine Gutin etal.s recently published optimal algorithm for enumerating the set of convex subgraphs under input/output constraints with application to custom instruction identification. We show that (i) suppressing some of the machinery in their algorithm results in a sub-optimal algorithm which is significantly faster in practice on real-world examples and that (ii) the constants of proportionality in the running time for both optimal and sub-optimal versions can be significantly improved by using additional output set filtering constraints.

Complexity of Computing Convex Subgraphs in Custom Instruction Synthesis

Synthesis of custom instruction processors from high-level application descriptions involves automated evaluation of data-flow subgraphs as custom instruction candidates. A subgraph <i>S</i> of a graph <i>D</i> , is convex if no two vertices of <i>S</i> are connected by a path in <i>D</i> that is not also in <i>S</i>. An algorithm for enumerating all convex subgraphs of a directed acyclic graph (DAG) under input, output, and forbidden vertex constraints was given by Pozzi, Atasu, and Ienne. We show that this algorithm makes no more than <i>O</i>(|<i>V</i>(<i>D</i>)|<i>N</i>_in+<i>N</i>_out+1) recursive calls, where |<i>V</i>(<i>D</i>)| is the number of vertices in <i>D</i>, and <i>N</i>_in and <i>N</i>_out are input and output constraints, respectively. Therefore, when <i>N</i>_in and <i>N</i>_out are constants, the algorithm is of polynomial complexity. Furthermore, a convex subgraph <i>S</i> is a maximal convex subgraph if it is not a proper subgraph of some other convex subgraph, assuming that both are valid under forbidden vertex constraints. The largest maximal convex subgraph is called the maximum convex subgraph. There exist popular algorithms that enumerate maximal convex subgraphs, which all have exponential worst-case time complexity. This work shows that although no polynomial-time maximal convex subgraph enumeration algorithm can exist, the related maximum convex subgraph problem can be solved in polynomial time.

An Algorithm for Finding Input-Output Constrained Convex Sets in an Acyclic Digraph

A set X of vertices of an acyclic graph is convex if any vertex on a directed path between elements of X is itself in X . We construct an algorithm for generating all input-output constrained convex (IOCC) sets in an acyclic digraph, which uses several novel ideas. We show that our algorithm is more efficient than algorithms described in the literature in both the worst case and computational experiments. IOCC sets of acyclic digraphs are of interest in the area of modern embedded processor technology.

Computational Properties of Fiction Writing and Collaborative Work

From the earliest days of computing, there have been tools to help shape narrative. Spell-checking, word counts, and readability analysis, give todays novelists tools that Dickens, Austen, and Shakespeare could only have dreamt of. However, such tools have focused on the word, or phrase levels. In the last decade, research focus has shifted to support for collaborative editing of documents. This work considers more sophisticated attempts to visualise the semantics, pace and rhythm within a narrative through data mining. We describe real life applications in two related domains.

The Domesday dataset: Linked open data in disability studies

Augmentative and alternative communication (AAC) devices provide the ability for many people with disabilities to make themselves understood. For the large proportion of users with an intellectual disability, these devices may be their only means of communication. Estimates of the number of AAC devices in use are vague and lack transparency. This prevents researchers from answering key questions like ‘How many people per 1000 are using electronic AAC?’ and ‘On average, how much money would fund a person’s AAC use for 12 months?’. This work presents the ‘Domesday dataset’, which allows researchers to answer research, policy, and prevalence questions on the landscape of AAC use within the United Kingdom. This dataset was constructed by making several hundred Freedom of Information requests. These requests asked public bodies who purchase AAC devices in the United Kingdom to supply details of every AAC purchase since 2006 including make, model, and year of purchase.

An algorithm for finding input-output constrained convex sets in an acyclic digraph

A set X of vertices of an acyclic graph is convex if any vertex on a directed walk between elements of X is itself in X. We construct an algorithm for generating all input-output constrained convex (IOCC) sets in an acyclic digraph, which uses several novel ideas. We show that the time complexity of our algorithm significantly improves the best one known from the literature. IOCC sets of acyclic digraphs are of interest in the area of modern embedded processor technology.