2,539 research outputs found
Complexity of and Algorithms for Borda Manipulation
We prove that it is NP-hard for a coalition of two manipulators to compute
how to manipulate the Borda voting rule. This resolves one of the last open
problems in the computational complexity of manipulating common voting rules.
Because of this NP-hardness, we treat computing a manipulation as an
approximation problem where we try to minimize the number of manipulators.
Based on ideas from bin packing and multiprocessor scheduling, we propose two
new approximation methods to compute manipulations of the Borda rule.
Experiments show that these methods significantly outperform the previous best
known %existing approximation method. We are able to find optimal manipulations
in almost all the randomly generated elections tested. Our results suggest
that, whilst computing a manipulation of the Borda rule by a coalition is
NP-hard, computational complexity may provide only a weak barrier against
manipulation in practice
Perceptual impairment in face identification with poor sleep
Previous studies have shown impaired memory for faces following restricted sleep. However, it is not known whether lack of sleep impairs performance on face identification tasks that do not rely on recognition memory, despite these tasks being more prevalent in security and forensic professionsâfor example, in photo-ID checks at national borders. Here we tested whether poor sleep affects accuracy on a standard test of face-matching ability that does not place demands on memory: the Glasgow Face-Matching Task (GFMT). In Experiment 1, participants who reported sleep disturbance consistent with insomnia disorder show impaired accuracy on the GFMT when compared with participants reporting normal sleep behaviour. In Experiment 2, we then used a sleep diary method to compare GFMT accuracy in a control group to participants reporting poor sleep on three consecutive nightsâand again found lower accuracy scores in the short sleep group. In both experiments, reduced face-matching accuracy in those with poorer sleep was not associated with lower confidence in their decisions, carrying implications for occupational settings where identification errors made with high confidence can have serious outcomes. These results suggest that sleep-related impairments in face memory reflect difficulties in perceptual encoding of identity, and point towards metacognitive impairment in face matching following poor sleep
Exploring Understanding of âChallenging Behaviourâ In the Context of People with Learning Disabilities: Views of Those Who Refer and Those Who Respond
Challenging behaviour is a label often given to people with learning disabilities when their behaviour challenges the system around them (Department of Health, 1993). There are numerous ways of understanding challenging behaviour. Given the mutual dependence between community learning disability teams and community support services in supporting people with learning disabilities, it was considered interesting to make explicit some of the ideas and assumptions that might enable or disable teams to work in consistent ways. This study draws on the research of Haydon-Laurelut, Nunkoosing and Millett (2014) and Nunkoosing and Haydon-Laurelut (2011).
Six support workers at day centres for adults with learning disabilities (referrers) and six clinical psychologists working at community learning disability teams (responders) took part in semi-structured interviews. The interviews asked about their understandings of challenging behaviour in the context of making and receiving referrals. Interviews were transcribed verbatim and analysed using thematic analysis.
Findings suggested that the support workers and clinical psychologists had quite similar ways of understanding challenging behaviour, which was an unexpected finding. They both used dominant discourses to talk about their understandings, as well as acknowledging that challenging behaviour is a social construction. These understandings were acknowledged to occur within the system or network around the person. Although there were shared understandings, still a schism existed in terms of how the services viewed each other. It was considered that something other than âunderstandingâ may be at the root of these differences and the suggestion made that the impact of emotions and relationships not being fully attended to and a common sense of powerlessness in the network could be important.
Implications of the findings on an individual, service, policy and societal level were considered as well as ideas for future research. A critical review is provided in the final part of this thesis
A STUDY OF RETENTION AND RECRUITMENT AT SOUTHERN AND MIDWESTERN WEEKLY U.S. NEWSPAPERS
Daily and weekly newspapers are closing at alarming rates, leaving readers without local coverage in many parts of the country. More than 5,000 of the remaining newspapers in the United States are weeklies, providing meeting coverage, agricultural news and keeping small towns informed. Yet, not nearly enough research exists about the people working at those newspapers. More than 1,000 email surveys were sent in early 2021 to weekly news editors, publishers or owners in seven states seeking opinions on successes and challenges in hiring and retaining weekly journalists. Survey results and follow-up interviews revealed a number of insights including data indicating weekly newspaper leaders are challenged by lack of funding, lack of qualified candidates and candidates lacking an interest in living in rural America. The weekly newspaper leaders also indicated that staffing challenges have negatively affected local news coverage. Workplace culture and community engagement were two of the main reasons journalists stayed in their jobs
Eliminating the Weakest Link: Making Manipulation Intractable?
Successive elimination of candidates is often a route to making manipulation
intractable to compute. We prove that eliminating candidates does not
necessarily increase the computational complexity of manipulation. However, for
many voting rules used in practice, the computational complexity increases. For
example, it is already known that it is NP-hard to compute how a single voter
can manipulate the result of single transferable voting (the elimination
version of plurality voting). We show here that it is NP-hard to compute how a
single voter can manipulate the result of the elimination version of veto
voting, of the closely related Coombs' rule, and of the elimination versions of
a general class of scoring rules.Comment: To appear in Proceedings of Twenty-Sixth Conference on Artificial
Intelligence (AAAI-12
Using mHealth to Improve Usage of Antenatal Care, Postnatal Care, and Immunization: A Systematic Review of the Literature
Mobile health (mHealth) technologies have been implemented in many low- and middle-income countries to address challenges in maternal and child health. Many of these technologies attempt to influence patientsâ, caretakersâ, or health workersâ behavior. The purpose of this study was to conduct a systematic review of the literature to determine what evidence exists for the effectiveness of mHealth tools to increase the coverage and use of antenatal care (ANC), postnatal care (PNC), and childhood immunizations through behavior change in low- and middle-income countries. The full text of 53 articles was reviewed and 10 articles were identified that met all inclusion criteria. The majority of studies used text or voice message reminders to influence patient behavior change (80%, n=8) and most were conducted in African countries (80%, n=8). All studies showed at least some evidence of effectiveness at changing behavior to improve antenatal care attendance, postnatal care attendance, or childhood immunization rates. However, many of the studies were observational and further rigorous evaluation of mHealth programs is needed in a broader variety of settings
Moving Beyond Fulfillment: Wisdom Years Stories of Passion, Perseverance, and Productivity
Seven participants were interviewed to uncover how they remain so productive in their wisdom years, those typically marked by retirement. Participants included a leading educational psychologist, a renowned national television news anchor, a four-time national champion collegiate coach, the founder and former chief executive of Arbor Day Foundation, a university scholar turned playwright, and two female adventurers who quit their jobs, sold their possessions, and have lived a nomadic life, hiking thousands of miles throughout America. Their wisdom years stories describe how and why they shun retirement and remain productive. The article concludes with seven advice-laden conclusions for readers: (a) Do not retire, but if you do, retire to something, (b) follow your bliss, (c) work hard, (d) offset aging challenges, (e) be inspired by role models, (f) be a life-long learner, and (g) take heed of the universe conspiring
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