52 research outputs found

    A self-adapting latency/power tradeoff model for replicated search engines

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    For many search settings, distributed/replicated search engines deploy a large number of machines to ensure efficient retrieval. This paper investigates how the power consumption of a replicated search engine can be automatically reduced when the system has low contention, without compromising its efficiency. We propose a novel self-adapting model to analyse the trade-off between latency and power consumption for distributed search engines. When query volumes are high and there is contention for the resources, the model automatically increases the necessary number of active machines in the system to maintain acceptable query response times. On the other hand, when the load of the system is low and the queries can be served easily, the model is able to reduce the number of active machines, leading to power savings. The model bases its decisions on examining the current and historical query loads of the search engine. Our proposal is formulated as a general dynamic decision problem, which can be quickly solved by dynamic programming in response to changing query loads. Thorough experiments are conducted to validate the usefulness of the proposed adaptive model using historical Web search traffic submitted to a commercial search engine. Our results show that our proposed self-adapting model can achieve an energy saving of 33% while only degrading mean query completion time by 10 ms compared to a baseline that provisions replicas based on a previous day's traffic

    Development of international multimodal transportation in the direction of Belarus-China

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    Belarus trade relations with China are currently growing. The development of relations with China is a priority direction of the foreign policy of the Republic of Belarus. However, the development of foreign trade relations between the Republic of Belarus and China is impossible without transport services that ensure the promotion of goods between trading partners

    Development of international multimodal transportation in the direction of Belarus-China

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    Belarus trade relations with China are currently growing. The development of relations with China is a priority direction of the foreign policy of the Republic of Belarus. However, the development of foreign trade relations between the Republic of Belarus and China is impossible without transport services that ensure the promotion of goods between trading partners

    Sensitivity and Bias in Decision-Making under Risk: Evaluating the Perception of Reward, Its Probability and Value

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    BACKGROUND: There are few clinical tools that assess decision-making under risk. Tests that characterize sensitivity and bias in decisions between prospects varying in magnitude and probability of gain may provide insights in conditions with anomalous reward-related behaviour. OBJECTIVE: We designed a simple test of how subjects integrate information about the magnitude and the probability of reward, which can determine discriminative thresholds and choice bias in decisions under risk. DESIGN/METHODS: Twenty subjects were required to choose between two explicitly described prospects, one with higher probability but lower magnitude of reward than the other, with the difference in expected value between the two prospects varying from 3 to 23%. RESULTS: Subjects showed a mean threshold sensitivity of 43% difference in expected value. Regarding choice bias, there was a 'risk premium' of 38%, indicating a tendency to choose higher probability over higher reward. An analysis using prospect theory showed that this risk premium is the predicted outcome of hypothesized non-linearities in the subjective perception of reward value and probability. CONCLUSIONS: This simple test provides a robust measure of discriminative value thresholds and biases in decisions under risk. Prospect theory can also make predictions about decisions when subjective perception of reward or probability is anomalous, as may occur in populations with dopaminergic or striatal dysfunction, such as Parkinson's disease and schizophrenia

    A qualitative study exploring midlife women’s stages of change from domestic violence towards freedom

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    Gold OABackground Domestic Violence (DV) remains a significant global health problem for women in contemporary society. Existing literature on midlife women’s experiences of domestic violence is limited and focuses on health implications. Leaving a violent relationship is a dynamic process that often requires multiple attempts and separations prior to final termination. The aim of this study was to explore the process of leaving a violent relationship for midlife women. Methods This qualitative study involved fifteen women aged between 40–55 who had accessed residential and non-residential community support services for domestic violence within the UK. Community-based support agencies provided these women with access to letters of invitation and participant information sheet explaining the study. The women notified agency staff who contacted the research team to arrange a mutually convenient time to meet within a safe place for both the women and researchers. It was stressed to all potential participants that no identifiable information would be shared with the agency staff. Women were considered survivors of DV if they defined themselves as such. Data were gathered through semi structured interviews, transcribed verbatim and thematically analysed. Results Midlife women appear to differ from younger women by transitioning quickly though the stages of change, moving rapidly through the breaking free onto the maintenance stage. This rapid transition is the resultant effect of living with long-term violence causing a shift in the women’s perception towards the violent partner, with an associated reclamation of power from within the violent relationship. A realisation that rapid departure from the violence may be critical in terms of personal safety, and the realisation that there was something ‘wrong’ within the relationship, a ‘day of dawning’ that had not been apparent previously appears to positively affect the trajectory of leaving. Conclusions Midlife women appeared to navigate through the stages of change in a rapid linear process, forging ahead and exiting the relationship with certainty and without considering options. Whilst these findings appear to differ from younger women’s process of leaving, further research is needed to explore and understand the optimum time for intervention and support to maximise midlife women’s opportunities to escape an abusive partner, before being reflected appropriately in policy and practice.This study received funding from The Research and Knowledge Transfer Office, The University of Chester, and from the Western Australian Health Promotion Foundation – ‘Healthway

    Big Losses Lead to Irrational Decision-Making in Gambling Situations: Relationship between Deliberation and Impulsivity

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    In gambling situations, we found a paradoxical reinforcing effect of high-risk decision-making after repeated big monetary losses. The computerized version of the Iowa Gambling Task (Bechara et al., 2000), which contained six big loss cards in deck B', was conducted on normal healthy college students. The results indicated that the total number of selections from deck A' and deck B' decreased across trials. However, there was no decrease in selections from deck B'. Detailed analysis of the card selections revealed that some people persisted in selecting from the “risky” deck B' as the number of big losses increased. This tendency was prominent in self-rated deliberative people. However, they were implicitly impulsive, as revealed by the matching familiar figure test. These results suggest that the gap between explicit deliberation and implicit impulsivity drew them into pathological gambling

    The transformation of a public monopoly into a public limited company through the privatisation process A critical legal study of the British and world-wide experience: the case study of privatising the telecommunications industry

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