Trust based collaborative filtering

k-nearest neighbour (kNN) collaborative filtering (CF), the widely successful algorithm supporting recommender systems, attempts to relieve the problem of information overload by generating predicted ratings for items users have not expressed their opinions about; to do so, each predicted rating is computed based on ratings given by like-minded individuals. Like-mindedness, or similarity-based recommendation, is the cause of a variety of problems that plague recommender systems. An alternative view of the problem, based on trust, offers the potential to address many of the previous limiations in CF. In this work we present a varation of kNN, the trusted k-nearest recommenders (or kNR) algorithm, which allows users to learn who and how much to trust one another by evaluating the utility of the rating information they receive. This method redefines the way CF is performed, and while avoiding some of the pitfalls that similarity-based CF is prone to, outperforms the basic similarity-based methods in terms of prediction accuracy

A global-scale analysis of the sharing economy model – an AirBnB case study

Abstract: The sharing economy model has changed the way in which people engage in a variety of activities, including travelling, trading, working, and lending/borrowing money. Several studies exist that aim to understand, quantify and model such phenomenon, but most such studies are geographically focused on countries in the Western World. Knowledge about the penetration and adoption of this novel market model in non-Western countries is much more limited, and almost completely lacking when it comes to emerging markets, where it was touted to bring the biggest benefits and be a game changer to uplift people economically. To close the gap, we chose Airbnb as an example of sharing economy model with worldwide market penetration, and performed a large-scale quantitative study of its penetration and adoption in seven cities in Asia, five cities in Latin America. We compared findings against seven cities in the Western World, and observed patterns to be similar across all locales, with two notable exceptions: the geographic penetration of such services, and the experience that guests travelling to such destinations shared in their reviews

The Impact of Simple Institutions in Experimental Economies with Poverty Traps

We introduce an experimental approach to study the effect of institutions on economic growth. In each period, agents produce and trade output in a market, and allocate it to consumption and investment. Productivity is higher if total capital stock is above a threshold. The threshold externality generates two steady states – a suboptimal poverty trap and an optimal steady state. In a baseline treatment, the economies converge to the poverty trap. However, the ability to make public announcements or to vote on competing and binding policies, increases output, welfare and capital stock. Combining these two simple institutions guarantees that the economies escape the poverty trap

It's Good to Talk: A Comparison of Using Voice Versus Screen-Based Interactions for Agent-Assisted Tasks

Voice assistants have become hugely popular in the home as domestic and entertainment devices. Recently, there has been a move towards developing them for work settings. For example, Alexa for Business and IBM Watson for Business were designed to improve productivity, by assisting with various tasks, such as scheduling meetings and taking minutes. However, this kind of assistance is largely limited to planning and managing user's work. How might they be developed to do more by way of empowering people at work? Our research is concerned with achieving this by developing an agent with the role of a facilitator that assists users during an ongoing task. Specifically, we were interested in whether the modality in which the agent interacts with users makes a difference: How does a voice versus screen-based agent interaction affect user behavior? We hypothesized that voice would be more immediate and emotive, resulting in more fluid conversations and interactions. Here, we describe a user study that compared the benefits of using voice versus screen-based interactions when interacting with a system incorporating an agent, involving pairs of participants doing an exploratory data analysis task that required them to make sense of a series of data visualizations. The findings from the study show marked differences between the two conditions, with voice resulting in more turn-taking in discussions, questions asked, more interactions with the system and a tendency towards more immediate, faster-paced discussions following agent prompts. We discuss the possible reasons for why talking and being prompted by a voice assistant may be preferable and more effective at mediating human-human conversations and we translate some of the key insights of this research into design implications

Drug addicted mothers and their empathic reactivity to painful cues.

Introduction: Mother-infant relationship is crucial for offspring\u2019s development. Substance-abuse has been shown to affect adults\u2019 ability to care for their children, in particular in the affective- relational aspects of parenting, such as the attachment bond and the ability to provide protection. Surprisingly, no previous study has explored neural responses associated with empathy towards children\u2019s pain in mothers with such history. Empathy is a more general construct than parenting and deficits in neural empathic responses may better explain failures in caring of addicted mothers. Aims of the study: This study was aimed at investigating the empathic response to pain inflicted by a dangerous tool to hands of kids when compared to neutral situations in a sample of mothers with history of drug-abuse. We used Event-Related Potentials (ERPs) technique to explore the time-course of neural empathic responses to pain by virtue of its excellent time resolution. In particular, we asked whether empathic responses to pain of children would differ in drug-addicted mothers compared to control group, during a relatively automatic early stage of processing or during a more controlled delayed one involving mentalizing. Material and methods: Event-related potentials (ERPs) have been recorded from drug-addicted mothers (i.e., clinical) and control groups to track neural activity in a pain decision task. Stimuli were pictures showing one infant hand in painful (harmful object applied to the hand) and neutral situations (harmful object located close to the hand). Results: Neural empathic responses towards children in pain differed between the two groups such that ERPs diverged between the painful and neutral stimulation at delayed stages of processing only for the clinical group. Conclusions: We interpreted these results as indicating that the control group implicitly judged also the neutral situations involving children as potentially painful supporting a lack of mentalizing abilities in the clinical group when compared with controls

Engaging without over-powering: A case study of a FLOSS project

This is the post-print version of the published chapter. The original publication is available at the link below. Copyright @ 2010 IFIP International Federation for Information Processing.The role of Open Source Software (OSS) in the e-learning business has become more and more fundamental in the last 10 years, as long as corporate and government organizations have developed their educational and training programs based on OSS out-of-the-box tools. This paper qualitatively documents the decision of the largest UK e-learning provider, the Open University, to adopt the Moodle e-learning system, and how it has been successfully deployed in its site after a multi-million investment. A further quantitative study also provides evidence of how a commercial stakeholder has been engaged with, and produced outputs for, the Moodle community. Lessons learned from this experience by the stakeholders include the crucial factors of contributing to the OSS community, and adapting to an evolving technology. It also becomes evident how commercial partners helped this OSS system to achieve the transition from an “average” OSS system to a successful multi-site, collaborative and community-based OSS project

A Movement-Tremors Recorder for Patients of Neurodegenerative Diseases

Neurodegenerative diseases such as Alzheimer, Parkinson, motor neuron, and Chorea affect millions of people today. Their effect on the central nervous system causes the loss of brain functions as well as motor disturbances and sometimes cognitive deficits. In such a scenario, the monitoring and evaluation of early symptoms are mandatory for the improvement of the patient's quality of life. Here, the authors describe the development, the laboratory calibration, and the "in-field validation" under the medical supervision of a movement tremors recorder for subjects affected by neurodegenerative diseases. The developed device is based on an array of four accelerometers connected to an embedded development board. This system is able to monitor tremor/movement, accidental falls, and, moreover, it can track the Alzheimer subjects' geographical position. A remote supervisor can collect data from the system through Bluetooth, Wi-Fi, or GSM connections. A data compression algorithm was developed directly on board in order to increase the efficiency of data transmission and reduce power consumptions

Análisis del comportamiento de una estructura plegada con sección transversal en forma de Z

Las estructuras plegadas prismáticas (EPP) están formadas por láminas rectangulares rígidamente unidas a lo largo de sus aristas comunes y apoyadas en sus extremos sobre diafragmas o pórticos. Estas estructuras se analizaron durante años mediante métodos manuales, suponiendo que su comportamiento estructural se puede descomponer en la dirección normal a las aristas y en la dirección longitudinal. En los últimos años, el advenimiento de las computadoras y el desarrollo de métodos numéricos, permite analizarlas con modelos más precisos. Si bien en la mayoría de las EPP los resultados obtenidos mediante métodos manuales y numéricos son similares, en la estructura con sección transversal en forma de Z se generan momentos longitudinales muy importantes que no eran considerados en el cálculo manual. En este trabajo se comparan soluciones manuales y numéricas y se analizan la magnitud de los esfuerzos que el cálculo manual no tiene en cuenta. Luego, con el objetivo de comprender y explicar las falencias del método manual, se resuelven estructuras con modificaciones en la geometría de la sección transversal mediante el método de los elementos finitos. Finalmente, se presenta una solución que mantiene las ventajas arquitectónicas y funcionales de la estructura plegada con sección transversal en forma de Z y no presenta momentos longitudinales excesivamente grandes.Publicado en: Mecánica Computacional vol. XXXV no.37Facultad de Ingenierí

Physikit: Data Engagement Through Physical Ambient Visualizations in the Home

Internet of things (IoT) devices and sensor kits have the potential to democratize the access, use, and appropriation of data. Despite the increased availability of low cost sensors, most of the produced data is "black box" in nature: users often do not know how to access or interpret data. We propose a "human-data design" approach in which end-users are given tools to create, share, and use data through tangible and physical visualizations. This paper introduces Physikit, a system designed to allow users to explore and engage with environmental data through physical ambient visualizations. We report on the design and implementation of Physikit, and present a two-week field study which showed that participants got an increased sense of the meaning of data, embellished and appropriated the basic visualizations to make them blend into their homes, and used the visualizations as a probe for community engagement and social behavior

Psychosocial empowerment-based interventions for smoking reduction: concepts, measures and outcomes. A systematic review

Although empowerment is a widely used concept in health-related areas, its definition remains unclear. While there is evidence for the effectiveness of empowerment interventions in improving some psychosocial factors linked to health (e.g. patient self-care strategy, coping skills, access and effective use of health services) and some health outcomes like mental health and HIV/AIDS-related behaviour, other data appear to contradict this. Moreover, concepts, measures, and outcomes related to empowerment are operationalized in different ways. Using the case of tobacco control programmes, we wanted to explore: (a) how research on smoking reduction/prevention has conceptualized empowerment; (b) which measures and instruments have been used to assess behaviour outcomes and the empowerment process. We hypothesized that the transformative potential that characterizes empowerment is marginally considered. A total of 18 studies reporting on the effect of prevention interventions on smoking and/or empowerment outcomes were reviewed. Two kinds of study were distinguished: (a) studies reporting behaviour outcomes without data about the impact on empowerment; (b) studies analysing the empowerment process. Among this latter type, some studies did not provide information about the specific behaviour (smoking), while others examined the impact of intervention on both smoking and empowerment. In about half of all studies, empowerment strategies were found to be effective in improving smoking outcomes, while no differences were found between intervention and control groups in the remaining studies. The present review suggests that pragmatic definitions of empowerment need to be developed in order to promote its transferability and evaluation