Trust as a service: A framework for trust management in cloud environments

Trust is one of the most concerned obstacles for the adoption and growth of cloud computing. Although several solutions have been proposed recently in managing trust feedbacks in cloud environments, how to determine the credibility of trust feedbacks is mostly neglected. In addition, managing trust feedbacks in cloud environments is a difficult problem due to unpredictable number of cloud service consumers and highly dynamic nature of cloud environments. In this paper, we propose the "Trust as a Service" (TaaS) framework to improve ways on trust management in cloud environments. In particular, we introduce an adaptive credibility model that distinguishes between credible trust feedbacks and malicious feedbacks by considering cloud service consumers' capability and majority consensus of their feedbacks. The approaches have been validated by the prototype system and experimental results.Talal H. Noor and Quan Z. Shenghttp://dl.acm.org/citation.cfm?id=205099

Self-confidence and knowledge of German ICU physicians in palliative care – a multicentre prospective study

Abstract Background Little is known about ICU physicians’ self-confidence and knowledge related to palliative care. Our objective was to investigate self-confidence and knowledge of German ICU physicians related to palliative care, and to assess the impact of work experience, gender, specialty and additional certifications in pain or palliative medicine. Methods In a multicentre prospective observational study ICU physicians of ten hospitals were asked to rate their self-confidence and to complete a multiple choice questionnaire for the assessment of knowledge. Beyond descriptive statistics and non-parametric tests for group comparisons, linear regression analysis was used to assess the impact of independent variable on self-confidence and knowledge. Spearman‘s rank test was calculated. Results 55% of answers in the knowledge test were correct and more than half of the participants rated themselves as “rather confident” or “confident”. Linear regression analysis revealed that an additional certificate in either pain or palliative medicine significantly increased both knowledge and self-confidence, but only 15 out of 137 participants had at least one of those certificates. Relation between self-confidence and the results of the knowledge test was weak (r = 0.270 in female) and very weak (r = −0.007 in male). Conclusions Although the questionnaire needs improvement according to the item analysis, it appears that, with respect to palliative care, ICU Physicians’ self-confidence is not related to their knowledge. An additional certificate in either pain or palliative medicine was positively correlated to both self-confidence and knowledge. However, only a minority of the participants were qualified through such a certificate

Cellular in vitro assays in the diagnosis of Hymenoptera venom allergy

BACKGROUND: The current diagnostic procedures of anaphylactic reactions to hymenoptera stings include intradermal tests, venom-specific IgE (sIgE) and possibly sting challenge tests. Sometimes, the culprit insect remains unidentified. The usefulness of the cellular assays CAST-ELISA and Flow-CAST in the management of hymenoptera venom allergy was investigated. METHODS: 134 patients with systemic reactions after a yellow jacket wasp and/or honey bee sting and 44 healthy controls underwent skin tests, as well as determination of sIgE (CAP-FEIA), leukocyte sulfidoleukotriene release (CAST-ELISA) and basophil CD63 expression (Flow-CAST) upon insect venom stimulation. The clinical diagnosis based on the history alone served as reference. Sensitivity, specificity, and positive and negative predictive value of all methods were compared. Concordance and correlations among methods were calculated. RESULTS: Sensitivity and specificity of all in vitro tests were consistently high. The combination of all tests (skin tests, sIgE, combined cellular assays) yielded a positive predictive value of 100% for both venoms, if all 3 were positive, and a negative predictive value of 100%, if at least 1 test was positive. Relative specificities were considerably higher for the cellular assays (honey bee: CAST 91.1%, Flow-CAST 85.7%; yellow jacket wasp: CAST 98.4%, Flow-CAST 92.1%) and allow the detection of the culprit insect in patients with reactivity to both insects. The concordance between methods was good. There is no correlation between severity of clinical reaction and cellular assays. CONCLUSION: CAST-ELISA and Flow-CAST are valuable additional diagnostic tools for establishing the true culprit insect in patients with unclear clinical history or sensitization to both insects

Credibility-based trust management for services in cloud environments

Trust management is one of the most challenging issues in the emerging cloud computing. Although many approaches have been proposed recently for trust management in cloud environments, not much attention has been given to determining the credibility of trust feedbacks. Moreover, the dynamic nature of cloud environments makes guaranteeing the availability of trust management services a difficult problem due to the unpredictable number of cloud consumers. In this paper, we propose a framework to improve ways on trust management in cloud environments. In particular, we introduce a credibility model that not only distinguishes between credible trust feedbacks, but also has the ability to detect the malicious trust feedbacks from attackers. We also present a replication determination model that dynamically decides the optimal replica number of the trust management service so that the trust management service can be always maintained at a desired availability level. The approaches have been validated by the prototype system and experimental results. © 2011 Springer-Verlag.Talal H. Noor and Quan Z. Shen

Trust management of services in cloud environments: obstacles and solutions

Trust management is one of the most challenging issues in the emerging cloud computing area. Over the past few years, many studies have proposed different techniques to address trust management issues. However, despite these past efforts, several trust management issues such as identification, privacy, personalization, integration, security, and scalability have been mostly neglected and need to be addressed before cloud computing can be fully embraced. In this article, we present an overview of the cloud service models and we survey the main techniques and research prototypes that efficiently support trust management of services in cloud environments. We present a generic analytical framework that assesses existing trust management research prototypes in cloud computing and relevant areas using a set of assessment criteria. Open research issues for trust management in cloud environments are also discussed.Talal H. Noor, Quan Z. Sheng, Sherali Zeadally, Jian Y