37 resultados para User perceived video quality on mobile devices
Resumo:
With a boom in the usage of mobile devices for traffic-heavy applications, mobile networks struggle to deliver good performance while saving resources to support more users and save on costs. In this paper, we propose enhanced strategies for the preemptive migration of content stored in Information-Centric Networking caches at the edge of LTE mobile networks. With such strategies, the concept of content following the users interested in it becomes a reality and content within caches is more optimized towards the requests of nearby users. Results show that the strategies are feasible, efficient and, when compared to default caching strategies, ensure that content is delivered faster to end users while using bandwidth and storage resources more efficiently at the core of the network.
Resumo:
This paper addresses the problem of service development based on GSM handset signaling. The aim is to achieve this goal without the participation of the users, which requires the use of a passive GSM receiver on the uplink. Since no tool for GSM uplink capturing was available, we developed a new method that can synchronize to multiple mobile devices by simply overhearing traffic between them and the network. Our work includes the implementation of modules for signal recovery, message reconstruction and parsing. The method has been validated against a benchmark solution on GSM downlink and independently evaluated on uplink channels. Initial evaluations show up to 99% success rate in message decoding, which is a very promising result. Moreover, we conducted measurements that reveal insights on the impact of signal power on the capturing performance and investigate possible reactive measures.
Resumo:
A common form of social regulation of an individual’s health behavior is social control. The contextual model of social control assumes that higher relationship quality goes along with more beneficial effects of social control on health behavior. This study examined potential differential moderating effects of different dimensions of relationship quality on the associations between positive and negative social control and smoking behavior and hiding smoking. The sample consisted of 144 smokers (n = 72 women; mean age = 31.78, SD = 10.04) with a nonsmoking partner. Positive and negative social control, dimensions of relationship quality consensus, cohesion and satisfaction, numbers of cigarettes smoked (NCS), hiding smoking (HS), and control variables were assessed at baseline. Four weeks later NCS and HS were assessed again. Only for smokers with high consensus, but not cohesion and satisfaction, a negative association between positive control and NCS emerged. Moreover, smokers with high consensus tended to report more HS when being positively and negatively socially controlled. This also emerged for cohesion and positive control. Satisfaction with the relationship did not display any interaction effects. This study’s results emphasize the importance of differentiating not only between positive and negative social control but also between different dimensions of relationship quality in order to gain a comprehensive understanding of the dynamics in romantic dyads with regard to social regulation of behavioral change.
Resumo:
Virtualisation of cellular networks can be seen as a way to significantly reduce the complexity of processes, required nowadays to provide reliable cellular networks. The Future Communication Architecture for Mobile Cloud Services: Mobile Cloud Networking (MCN) is a EU FP7 Large-scale Integrating Project (IP) funded by the European Commission that is focusing on cloud computing concepts to achieve virtualisation of cellular networks. It aims at the development of a fully cloud-based mobile communication and application platform, or more specifically, it aims to investigate, implement and evaluate the technological foundations for the mobile communication system of Long Term Evolution (LTE), based on Mobile Network plus Decentralized Computing plus Smart Storage offered as one atomic service: On-Demand, Elastic and Pay-As-You-Go. This paper provides a brief overview of the MCN project and discusses the challenges that need to be solved.
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This study analysed mechanisms through which stress-coping and temptation-coping strategies were associated with lapses. Furthermore, we explored whether distinct coping strategies differentially predicted reduced lapse risk, lower urge levels, or a weaker association between urge levels and lapses during the first week of an unassisted smoking cessation attempt. Participants were recruited via the internet and mass media in Switzerland. Ecological momentary assessment (EMA) with mobile devices was used to assess urge levels and lapses. Online questionnaires were used to measure smoking behaviours and coping variables at baseline, as well as smoking behaviour at the three-month follow-up. The sample consisted of 243 individuals, aged 20 to 40, who reported 4199 observations. Findings of multilevel regression analyses show that coping was mainly associated with a reduced lapse risk and not with lower urge levels or a weaker association between urge levels and lapses. 'Calming down' and 'commitment to change' predicted a lower lapse risk and also a weaker relation between urge levels and lapses. 'Stimulus control' predicted a lower lapse risk and lower urge levels. Conversely, 'task-orientation' and 'risk assessment' were related to higher lapse risk and 'risk assessment' also to higher urge levels. Disengagement coping i.e. 'eating or shopping', 'distraction', and 'mobilising social support' did not affect lapse risk. Promising coping strategies during the initial stage of smoking cessation attempt are targeted directly at reducing the lapse risk and are characterised by engagement with the stressor or one's reactions towards the stressor and a focus on positive consequences instead of health risks.
Resumo:
This work contributes to the ongoing debate on the productivity paradox by considering CIOs’ perceptions of IT business value. Applying regression analysis to data from an international survey, we study how the adoption of certain types of enterprise software affects the CIOs’ perception of the impact of IT on the firm’s business activities and vice versa. Other potentially important factors such as country, sector and size of the firms are also taken into account. Our results indicate a more significant support for the impact of perceived IT benefits on adoption of enterprise software than vice versa. CIOs based in the US perceive IT benefits more strongly than their German counterparts. Furthermore, certain types of enterprise software seem to be more prevalent in the US.