7,481 research outputs found

    An Abstract Formal Basis for Digital Crowds

    Get PDF
    Crowdsourcing, together with its related approaches, has become very popular in recent years. All crowdsourcing processes involve the participation of a digital crowd, a large number of people that access a single Internet platform or shared service. In this paper we explore the possibility of applying formal methods, typically used for the verification of software and hardware systems, in analysing the behaviour of a digital crowd. More precisely, we provide a formal description language for specifying digital crowds. We represent digital crowds in which the agents do not directly communicate with each other. We further show how this specification can provide the basis for sophisticated formal methods, in particular formal verification.Comment: 32 pages, 4 figure

    An agent-based approach to assess drivers’ interaction with pre-trip information systems.

    Get PDF
    This article reports on the practical use of a multi-agent microsimulation framework to address the issue of assessing drivers’ responses to pretrip information systems. The population of drivers is represented as a community of autonomous agents, and travel demand results from the decision-making deliberation performed by each individual of the population as regards route and departure time. A simple simulation scenario was devised, where pretrip information was made available to users on an individual basis so that its effects at the aggregate level could be observed. The simulation results show that the overall performance of the system is very likely affected by exogenous information, and these results are ascribed to demand formation and network topology. The expressiveness offered by cognitive approaches based on predicate logics, such as the one used in this research, appears to be a promising approximation to fostering more complex behavior modelling, allowing us to represent many of the mental aspects involved in the deliberation process

    Shipping markets and freight rates: an analysis of the Baltic Dry Index

    Get PDF
    Shipping, although a crucial component of the transportation of commodities worldwide, is hardly present in the finance literature at this point. The first and foremost goal of this paper is to describe and explain from an economic perspective the key features of shipping markets; the second one is to analyze the behavior of freight rates, which define the final cost of an imported commodity. We focus on the major index, the BDI (Baltic Dry Index) and propose some diffusion models able to capture the unique features of its trajectories, namely large swings and continuity. Their performance is exhibited on a database covering the period 1988-2010. Such spot models should facilitate the growth of the market of freight rates options, a safe hedging instrument for farmers and cooperatives that ship their grains to distant destinations

    Social Mental Shaping: Modelling the Impact of Sociality on Autonomous Agents' Mental States

    No full text
    This paper presents a framework that captures how the social nature of agents that are situated in a multi-agent environment impacts upon their individual mental states. Roles and relationships provide an abstraction upon which we develop the notion of social mental shaping. This allows us to extend the standard Belief-Desire-Intention model to account for how common social phenomena (e.g. cooperation, collaborative problem-solving and negotiation) can be integrated into a unified theoretical perspective that reflects a fully explicated model of the autonomous agent's mental state

    The Trouble with the MDGs: Confronting Expectations of Aid and Development Success

    Get PDF
    The Millennium Development Goals (MDGs) are unlikely to be met by 2015, even if huge increases in development assistance materialize. The MDGs are a set of quantitative, time-bound targets for indicators such as poverty, education and mortality in developing countries adopted unanimously by the UN in 2000. However, the rates of progress required by many of the goals are at the edges of or beyond historical precedent. At the same time, there appear to be limits to the degree to which aid can contribute to development outcomes. Estimates of the ‘cost’ of reaching the MDGs are nevertheless frequently misinterpreted to mean that a certain quantity of aid—such as the oft-cited $50 billion—could cause the Goals to be met. Despite many benefits of the MDGs, there has been little discussion so far of potential costs of the specific form taken by these goals, especially the creation of unreasonable expectations about what is achievable in a short time frame and about the role of aid in the development process. Many countries making extraordinarily rapid progress on MDG indicators, due in large part to aid, will nonetheless not reach the MDGs. Unrealistic targets thus may turn successes into perceptions of failure, serving to undermine future constituencies for aid (in donors) and reform (in recipients). This would be unfortunate given the vital role of aid and reform in the development process and the need for long-term, sustained aid commitments. Though goal-setting can be useful, these particular goals might be better viewed not as practical targets but instead as valuable reminders of the stark contrast between the world we have and the world we want, and as a call to redouble our search for interventions to close the gap more rapidly.Millennium Development Goals (MDGs), development assistance

    Use of recurrence quantification analysis to examine associations between changes in text structure across an expressive writing intervention and reductions in distress symptoms in women wth breast cancer

    No full text
    The current study presents an exploratory analysis of using Recurrence Quantification Analysis (RQA) to analyze text data from an Expressive Writing Intervention (EWI) for Danish women treated for Breast Cancer. The analyses are based on the analysis of essays from a subsample with the average age 54.6 years (SD = 9.0), who completed questionnaires for cancer-related distress (IES) and depression symptoms (BDI-SF). The results show a significant association between an increase in recurrent patterns of text structure from first to last writing session and a decrease in cancer-related distress at 3 months post-intervention. Furthermore, the change in structure from first to last essay displayed a moderate, but significant correlation with change in cancer-related distress from baseline to 9 months post-intervention. The results suggest that changes in recurrence patterns of text structure might be an indicator of cognitive restructuring that leads to amelioration of cancer-specific distress

    The Trouble with the MDGs: Confronting Expectations of Aid and Development Success

    Get PDF
    Growing concern that the Millennium Development Goals (MDGs) will not be achieved by 2015 should not obscure the bigger picture that development progress has been occurring at unprecedented levels over the past thirty or more years. At the same time, the MDGs may perhaps create an unnecessary pessimism toward aid by labeling many development successes as failures. The first MDG of halving the number of people living in poverty will probably be met globally, but for most developing countries to achieve this at the national level, the growth rates required are at the bounds of historical precedent. Additionally, there appears to be only a weak relationship between aid and rapid economic growth. A similar problem holds for many of the other education and health goals. For many countries, the rates of progress required to meet the MDGs by 2015 are extremely high compared to historical experience and there is only a tenuous relationship between expenditure and outcomes. Nevertheless, estimates that an additional $50 billion in aid per year is necessary to meet the MDGs are frequently misinterpreted to suggest that it is also sufficient. Most of the goals are unlikely to be reached, but this will probably not be due primarily to shortfalls in aid. This is in part because development is a long-term and complex process dependent on relieving more than a supply-side constraint on resources. Aid remains vital and contributes to development progress, but even considerable increases in aid are unlikely to buy these particular goals. Goal setting is also useful, but continuing to suggest that the MDGs can be met may undermine future constituencies for aid (in donors) and reform (in recipients). The MDGs might be better viewed not as realistic targets but as reminders of the stark contrast between the world we want and the world we have, and a call to redouble our search for interventions to close the gap.Millennium Development Goals poverty economic growth

    Hermeneutic single case efficacy design: A systematic review of published research and current standards

    Get PDF
    open4siThis article systematically reviews the methodological characteristics of Hermeneutic Single Case Efficacy Design (HSCED) studies published in peer-reviewed journals. HSCED provides researchers with a flexible and viable alternative to both between-groups and within-subject experimental designs. This article includes a description of the evolution of the methodology distinctive to HSCED; a discussion of results of HSCED studies considered within a framework of contemporary standards and guidelines for systematic case study research; a presentation of recommendations for key characteristics (e.g., diagnosis, hermeneutic analysis, adjudication procedure). Overall, the aim is provide researchers and reviewers with a resource for conducting and evaluating HSCED research. The results of a systematic review of 13 studies suggests that published HSCED research meets contemporary criteria for systematic case study research. Hermeneutic analysis and adjudication emerged as areas of HSCED practice characterized by a diversity of procedures. Although consensus exists along key dimensions of HSCED, there remains a need for further evaluation of adjudication procedures and reporting standards.openBenelli, Enrico; De Carlo, Alessandro; Biffi, Diana; Mcleod, JohnBenelli, Enrico; De Carlo, Alessandro; Biffi, Diana; Mcleod, Joh

    Early in-session predictors of response to trauma-focused cognitive therapy

    Get PDF
    Volume 1 of this thesis examines the predictors of response to trauma-focused treatment for posttraumatic stress disorder (PTSD). It is presented in three parts. Part 1 is a literature review of research evaluating the impact of trauma-focused therapy for PTSD on comorbid symptoms of depression. The Downs and Black (1998) checklist was used to assess study quality. Results indicated that both trauma-focused CBT and EMDR treatments were effective in reducing comorbid depression symptoms. However, as interventions varied widely and some studies were affected by significant methodological problems, the generalisability of these results may be limited, and thus areas for further research are also suggested. Part 2 is an empirical study exploring early in-session client and therapist factors that predict later response to treatment. Audio and video recordings of the first or second therapy session of 54 known treatment responders or non-responders were blind-rated for client perseverative thinking, therapist adherence and therapeutic alliance. Results revealed that more perseverative thinking was observed for non-responders than responders to treatment. No group differences were found in regards to therapist adherence or therapeutic alliance. Exploratory analyses revealed that across the sample as a whole, perseverative thinking was associated with reduced therapist adherence to the treatment manual and poorer therapeutic alliance. As this study is one of the first of its kind in this area, recommendations were made for future research opportunities to explore these findings further. Part 3 is a critical appraisal of the empirical study. This elaborates on the main findings of this project and discusses the methodological challenges involved in undertaking this type of research, particularly developing and applying a novel coding frame

    The role of tropical forests in supporting biodiversity and hydrological integrity: a synoptic overview

    Get PDF
    Conservation of high-biodiversity tropical forests is sometimes justified on the basis of assumed hydrological benefits - in particular, the reduction of flooding hazards for downstream floodplain populations. However, the"far-field"link between deforestation and distant flooding has been difficult to demonstrate empirically. This simulation study assesses the relationship between forest cover and hydrology for all river basins intersecting the world's tropical forest biomes. The study develops a consistent set of pan-tropical land cover maps gridded at one-half degree latitude and longitude. It integrates these data with existing global biogeophysical data. The study applies the Water Balance Model - a coarse-scale process-based hydrological model - to assess the impact of land cover changes on runoff. It quantifies the impacts of forest conversion on biodiversity and hydrology for two scenarios - historical forest conversion and the potential future conversion of the most threatened remaining tropical forests. A worst-case scenario of complete conversion of the most threatened of the remaining forested areas would mean the loss of another three million km2 of tropical forests. Increased annual yield from the conversion of threatened tropical forests would be less than 5 percent of contemporary yield in aggregate. However, about 100 million people - 80 million of them in floodplains - would experience increases of more than 25 percent in annual water flows. This might be associated with commensurate increases in peak flows, though further analysis would be necessary to gauge the impact on flooding. The study highlights basins in Southeast Asia, southern China, and Latin America that warrant further study.Wetlands,Forestry,Climate Change,Drylands&Desertification,Earth Sciences&GIS
    corecore