Patterns of construing and post-traumatic stress disorder

Four studies were conducted in order to investigate the way people construe their most stressful and traumatic experiences. Personal constl1,lct theory was the main theoretical approach used in all studies but the thesis also drew upon social const~ctionist perspectives. In study one, a clinical sample of people diagnosed with PTSD (n = 36) was tested using repertory grids and questionnaires. The study tested the viability of the personal construct model of PTSD (Sewell et aI, 1996). Results did not support the model and a new personal construct model was proposed. In study two, an investigation into a number of methodological issues relating to the hierarchical-classes analysis (HICbAS), as applied to PTSD conceptualizations within the personal construct model, was conducted. Results revealed that its use in the analysis of repertory grid data was based on flawed assumptions. Corrective suggestions were proposed and the TUCKER-HICLAS software was introduced in order to improve the analysis of repertory grid data. In study three, a student sample (n = 114) was divided into groups according to some personality traits (high/low anxiety, repression, dissociatIon, thought suppression). The students completed repertory grids using as elements life events, including the most stressful event of their lives, and consequently their patterns of construing these events were compared between them as well as with the patterns found among the PTSD ' , patients from Study One. Results were counterintuitive in the sense that it was found that the low anxious group was the most similar to the PTSD group. A model based on the concepts of anticipation and epistemic control was proposed to account for the findings. In study four, an asylum seeker and refugee sample (n = 5) diagnosed with PTSD was interviewed and asked to complete repertory grids. Results showed that this population tends to construe their traumas in terms of constructs expressing social relations rather than psychological states, as commonly found among non-refugee people. Central to their construing of trauma was found to be the concept of 'limbo'. The psychosocial effects of limbo were explored through the anthropological concept of liminality. It was propose'd that issues of functionality should be incorporated into the diagnosis and treatment of trauma among asylum seekers and refugees as well as the general population

ARTEMIS: Real-Time Detection and Automatic Mitigation for BGP Prefix Hijacking

Prefix hijacking is a common phenomenon in the Internet that often causes routing problems and economic losses. In this demo, we propose ARTEMIS, a tool that enables network administrators to detect and mitigate prefix hijacking incidents, against their own prefixes. ARTEMIS is based on the real-time monitoring of BGP data in the Internet, and software-defined networking (SDN) principles, and can completely mitigate a prefix hijacking within a few minutes (e.g., 5-6 mins in our experiments) after it has been launched

Soft Cache Hits and the Impact of Alternative Content Recommendations on Mobile Edge Caching

Caching popular content at the edge of future mobile networks has been widely considered in order to alleviate the impact of the data tsunami on both the access and backhaul networks. A number of interesting techniques have been proposed, including femto-caching and "delayed" or opportunistic cache access. Nevertheless, the majority of these approaches suffer from the rather limited storage capacity of the edge caches, compared to the tremendous and rapidly increasing size of the Internet content catalog. We propose to depart from the assumption of hard cache misses, common in most existing works, and consider "soft" cache misses, where if the original content is not available, an alternative content that is locally cached can be recommended. Given that Internet content consumption is increasingly entertainment-oriented, we believe that a related content could often lead to complete or at least partial user satisfaction, without the need to retrieve the original content over expensive links. In this paper, we formulate the problem of optimal edge caching with soft cache hits, in the context of delayed access, and analyze the expected gains. We then show using synthetic and real datasets of related video contents that promising caching gains could be achieved in practice