148,643 research outputs found

    Paper-backs: a literary trend in communications.

    Full text link
    Thesis (M.S.)--Boston Universit

    Towards Tight Lower Bounds for Range Reporting on the RAM

    Full text link
    In the orthogonal range reporting problem, we are to preprocess a set of nn points with integer coordinates on a U×UU \times U grid. The goal is to support reporting all kk points inside an axis-aligned query rectangle. This is one of the most fundamental data structure problems in databases and computational geometry. Despite the importance of the problem its complexity remains unresolved in the word-RAM. On the upper bound side, three best tradeoffs exists: (1.) Query time O(lg⁥lg⁥n+k)O(\lg \lg n + k) with O(nlgΔn)O(nlg^{\varepsilon}n) words of space for any constant Δ>0\varepsilon>0. (2.) Query time O((1+k)lg⁥lg⁥n)O((1 + k) \lg \lg n) with O(nlg⁥lg⁥n)O(n \lg \lg n) words of space. (3.) Query time O((1+k)lg⁥Δn)O((1+k)\lg^{\varepsilon} n) with optimal O(n)O(n) words of space. However, the only known query time lower bound is Ω(log⁥log⁥n+k)\Omega(\log \log n +k), even for linear space data structures. All three current best upper bound tradeoffs are derived by reducing range reporting to a ball-inheritance problem. Ball-inheritance is a problem that essentially encapsulates all previous attempts at solving range reporting in the word-RAM. In this paper we make progress towards closing the gap between the upper and lower bounds for range reporting by proving cell probe lower bounds for ball-inheritance. Our lower bounds are tight for a large range of parameters, excluding any further progress for range reporting using the ball-inheritance reduction

    Relating Developers’ Concepts and Artefact Vocabulary in a Financial Software Module

    Get PDF
    Developers working on unfamiliar systems are challenged to accurately identify where and how high-level concepts are implemented in the source code. Without additional help, concept location can become a tedious, time-consuming and error-prone task. In this paper we study an industrial financial application for which we had access to the user guide, the source code, and some change requests. We compared the relative importance of the domain concepts, as understood by developers, in the user manual and in the source code. We also searched the code for the concepts occurring in change requests, to see if they could point developers to code to be modified. We varied the searches (using exact and stem matching, discarding stop-words, etc.) and present the precision and recall. We discuss the implication of our results for maintenance

    Survey of the lesser silver water beetle Hydrochara caraboides in Cheshire

    Get PDF
    This is the report on the Survey of the Lesser Silver Water Beetle Hydrochara caraboides in Cheshire 1997 by the English Nature Research Reports. The three surveyed areas were the ponds at Reaseheath, Mickle Trafford and Brookhouse Farm. The report goes through the method of survey and individual results for each location/pond, aspects of the breeding sites considered favourable to Hydrochara caraboides as depth, vegetation, predators and prey species, surrounding land. It comes with suggestions for further work and appendixes. Appendix A contains tabulated lists of plants and invertebrates found in the various ponds, Appendix B shows grid references and a brief description of ponds at Brookhouse Farm, pond diagrams are plotted in Appendix C

    A robot swarm assisting a human fire-fighter

    Get PDF
    Emergencies in industrial warehouses are a major concern for fire-fighters. The large dimensions, together with the development of dense smoke that drastically reduces visibility, represent major challenges. The GUARDIANS robot swarm is designed to assist fire-fighters in searching a large warehouse. In this paper we discuss the technology developed for a swarm of robots assisting fire-fighters. We explain the swarming algorithms that provide the functionality by which the robots react to and follow humans while no communication is required. Next we discuss the wireless communication system, which is a so-called mobile ad-hoc network. The communication network provides also the means to locate the robots and humans. Thus, the robot swarm is able to provide guidance information to the humans. Together with the fire-fighters we explored how the robot swarm should feed information back to the human fire-fighter. We have designed and experimented with interfaces for presenting swarm-based information to human beings

    Italy in the Australian news media, 2005-2012

    Get PDF
    Presents a systematic analysis of the coverage of Italian matters in the Australian news media in the period 2005-2012. Executive summary The study presents a systematic analysis of the coverage of Italian matters in the Australian news media in the period 2005-2012. As far as the authors are aware it is largest study of the representation of Italy in the news media of a foreign country ever undertaken.   The study was undertaken by the University of Canberra’s News and Media Research Centre (N&MRC) in association with the On. Marco Fedi, who commissioned research on coverage of Italian politics in selected Australian newspapers.   During the period covered by the study there was more than usual interest in Italian political developments in Australia, both because of their inherent newsworthiness and because of the newly-acquired right of direct participation of expatriate Italians in Australia in the 2006 and 2008 Italian general elections.   To obtain as wide a view of Italy in the Australian news as practicable both the press and television were included in the study.   Three well -known and respected newspapers, namely The Australian, the major national newspaper, The Sydney Morning Herald (SMH) published in Sydney and The Age published in Melbourne were selected for the study. All editorial matter in all issues of these newspapers for the years 2005-2012 was searched using ‘Factiva’– a business information and research tool owned by Dow Jones & Company. The initial search for relevant news in the press generated a very large number of items (around 10,000) which were then assessed individually for relevance and eligibility for inclusion in the analysis. This process generated a data set of 5325 news items

    Crime scripting: A systematic review

    Get PDF
    The file attached to this record is the author's final peer reviewed version.More than two decades after the publication of Cornish’s seminal work about the script-theoretic approach to crime analysis, this article examines how the concept has been applied in our community. The study provides evidence confirming that the approach is increasingly popular; and takes stock of crime scripting practices through a systematic review of over one hundred scripts published between 1994 and 2018. The results offer the first comprehensive picture of this approach, and highlights new directions for those interested in using data from cyber-systems and the Internet of Things to develop effective situational crime prevention measures

    Who Responds to Voluntary Cognitive Tests in Household Surveys? The Role of Labour Market Status, Respondent Confidence, Motivation and a Culture of Learning in South Africa

    Get PDF
    Both South Africa’s labour market and education system were directly influenced by the separate development policies of the apartheid regime. To this day, great inequalities persist in both domains. South Africa’s performance in standardized international test scores (such as TIMMS) is poor even relative to most developing countries. Furthermore, the better quality of outcomes in former white schools still leaves learners from former black schools at a disadvantage that feeds through to severe labour market inequalities. This study is the first in a series of papers that attempts to understand the role of school quality on labour market outcomes. Here we scrutinize the measurement of numeracy test scores in the National Income Dynamics Survey (NIDS) of 2008, particularly in light of potential sample selection issues. While this survey measures standard welfare and labour market indicators, it is one of the first in South Africa to also ask respondents to complete a concurrent numeracy test. Response rates on this module were particularly low, given that the test was taken on a voluntary basis. We develop a basic empirical model to understand who is likely to take the test. We postulate that discouraged workers’ low propensity to take the test is correlated with their reduced motivation to undertake job search, that the searching unemployed are highly motivated to take the test (as they wish to gauge their ability or practice assessments while embarking on the job search process), the poorest among the self-employed face severe time opportunity costs (as their low incomes are less secure than those of salaried workers) and the richest amongst the employed exhibit an income effect (in that the time opportunity costs of their high incomes reduce their willingness to respond to the numeracy test). Furthermore, locational effects suggest that those residing in geographical “points of entry” into the labour market are also more likely to take the test. The young (who are still in education) and the most educated (in the whole population) also tend to answer the test more readily. The latter observations indicate that some form of confidence in respondents’ own abilities drives their response patterns. To explain these observed features, we construct composite indices of motivation/emotional well-being and individuals’ confidence in their writing abilities using multiple correspondence analysis. While each of these psychological and behavioural factors is a strong predictor of test response, they do not entirely eliminate the independent contributions of each of the observed influences mentioned above. Coefficient magnitudes of each of the sociodemographic variables are, however, reduced, indicating that the particular behavioural influences introduced in later models tell some of the story. Additional uncaptured behavioural and motivational factors are therefore investigated. Firstly, we investigate the role of survey fatigue (by controlling for the time it took to complete the survey before the test was administered), which plays an important role in the black and coloured subpopulations. It furthermore explains why the wealthiest amongst the formally employed are less likely to complete the numeracy test. However, surprisingly, “pseudoaltruistic” effects appear amongst the (wealthier) white population, in that the longer the duration of the preceding questions, the more likely they are to care about answering the test. However, this result cannot be generalized to the whole white population, as response rates were very low among this group. Secondly, (household) peer effects are strong throughout the population, suggesting that a culture of learning is pivotal in understanding response patterns. The results of this paper suggest that broad sociodemographic and labour market features remain important determinants of test response, even after controlling for behavioural features. This suggests that subsequent labour market work must take these drivers into account to avoid the risk of sample selection bias.education, behavioural economics, survey design, voluntary assessment, numeracy, survey non-response, sample selection bias, respondent confidence, motivation, culture of learning, South Africa

    What do faculty and students really think about e-books?

    Get PDF
    Purpose - The purpose of this article is to report on a large-scale survey that was carried Out to assess academic users' awareness, perceptions and existing levels of use of e-books. The survey also seeks to find out about the purposes to which electronic books were put, and to obtain an understanding of the most effective library marketing and communication channels.Design/methodology/approach - An e-mail invitation to participate in the survey was distributed to all UCL staff and students (approximately 27,000) in November 2006, and 1,818 completions were received, an effective response rate of at least 6.7 per cent. Statistical analyses were carried out on the data using Software Package for Social Sciences (SPSS).Findings - The survey findings point to various ways in which user uptake and acceptance of e-books may be encouraged. Book discovery behaviour, a key issue for publishers and librarians in both print and electronic environments, emerges as a critical focus for service delivery and enhancement.Originality/value - The survey is part of an action research project, CIBER's SuperBook, that will further investigate the issues raised in this initial benchmarking survey using deep log analysis and qualitative methods. The paper partly fills the gap in the literature on e-books which has mainly focused on usage and not the users

    Redundant regulation? : competition and consumer choice in the residential energy markets

    Get PDF
    The UK energy regulator has recently removed price controls from about 40% of residential energy users, and plans total deregulation of the gas and electricity markets by 2002, relying instead on general competition policy to protect consumers. We examine responses to a specially commissioned survey of over one thousand consumers, to identify determinants of consumer choice between suppliers. We conclude that there are substantial switching costs which seem higher for more vulnerable groups. By assessing the savings which consumers require to switch supplier, we deduce that the incumbent retains considerable market power, suggesting that some continued regulation may be necessary
    • 

    corecore