1,252 research outputs found
Soft Constraints for Security
No full textAbstractIntegrity policies and cryptographic protocols have much in common. They allow for a number of participating principals, and consist of sets of rules controlling the actions that principals should or should not perform. They are intended to uphold various security properties, the crucial ones being integrity, confidentiality and authentication.This paper takes a unified view to the analysis of integrity policies and cryptographic protocols: they are artifacts that must be designed to be sufficiently robust to attack given an understood threat model. For example, integrity policy rules provide resilience to the threat of internal fraud, while cryptographic protocols provide resilience to the threat of replay and related attacks. The framework is modelled using (soft) constraints and analysis corresponds to the soft constraint satisfaction problem. Soft constraints facilitate a quantitative approach to analyzing integrity, confidentiality and authentication. Examples will be given: an integrity policy may achieve different levels of integrity under different circumstances; a protocol message may enjoy different levels of confidentiality for different principals; a principal can achieve different levels of authentication with different principals
A soft constraint-based approach to the cascade vulnerability problem
No full textThe security of a network configuration is based not just on the security of its individual components and their direct interconnections, but also on the potential for systems to interoperate indirectly across network routes. Such interoperation has been shown to provide the potential for cascading paths that violate security, in a circuitous manner, across a network. In this paper we show how constraint satisfaction provides a natural approach to expressing the necessary constraints to ensure multilevel security across a network configuration. In particular, soft constraints are used to detect and eliminate the cascading network paths that compromise security. Taking this approach results in practical advancements over existing solutions to this problem. In particular, constraint satisfaction highlights the set of all cascading paths, which we can eliminate in polynomial time by breaking a minimal number of system links to ensure security
De la figuration du tragique Chris Kraus, Simon Goldhill, Helene P. Foley, Jás Elsner, Vizualizing the Tragic. Drama, Myth, and Ritual in Greek Art and Literature. Essays in Honour of Froma Zeitlin, Oxford, Oxford University Press, 2007
No full textVillacèque Noémie. De la figuration du tragique Chris Kraus, Simon Goldhill, Helene P. Foley, Jás Elsner, Vizualizing the Tragic. Drama, Myth, and Ritual in Greek Art and Literature. Essays in Honour of Froma Zeitlin, Oxford, Oxford University Press, 2007. In: Dialogues d'histoire ancienne, vol. 35, n°2, 2009. pp. 229-231
De la figuration du tragique Chris Kraus, Simon Goldhill, Helene P. Foley, Jás Elsner, Vizualizing the Tragic. Drama, Myth, and Ritual in Greek Art and Literature. Essays in Honour of Froma Zeitlin, Oxford, Oxford University Press, 2007
No full textVillacèque Noémie. De la figuration du tragique Chris Kraus, Simon Goldhill, Helene P. Foley, Jás Elsner, Vizualizing the Tragic. Drama, Myth, and Ritual in Greek Art and Literature. Essays in Honour of Froma Zeitlin, Oxford, Oxford University Press, 2007. In: Dialogues d'histoire ancienne, vol. 35, n°2, 2009. pp. 229-231
Division of labour and sharing of knowledge for synchronous collaborative information retrieval
No full textSynchronous collaborative information retrieval (SCIR) is concerned with supporting two or more users who search together at the same time in order to satisfy a shared information need. SCIR systems represent a paradigmatic shift in the way we view information retrieval, moving from an individual to a group process and as such the development of novel IR techniques is needed to support this. In this article we present what we believe are two key concepts for the development of effective SCIR namely division of labour (DoL) and sharing of knowledge (SoK). Together these concepts enable coordinated SCIR such that redundancy across group members is reduced whilst enabling each group member to benefit from the discoveries of their collaborators. In this article we outline techniques from state-of-the-art SCIR systems which support these two concepts, primarily through the provision of awareness widgets. We then outline some of our own work into system-mediated techniques for division of labour and sharing of knowledge in SCIR. Finally we conclude with a discussion on some possible future trends for these two coordination techniques
Author Co-Citation Analysis (ACA): a powerful tool for representing implicit knowledge of scholar knowledge workers
No full textIn the last decade, knowledge has emerged as one of the most important and valuable organizational assets. Gradually this importance caused to emergence of new discipline entitled ―knowledge management‖. However one of the major challenges of knowledge management is conversion implicit or tacit knowledge to explicit knowledge. Thus Making knowledge visible so that it can be better accessed, discussed, valued or generally managed is a long-standing objective in knowledge management. Accordingly in this paper author co- citation analysis (ACA) will be proposed as an efficient technique of knowledge visualization in academia (Scholar knowledge workers)
Facts and Fallacies about U.S. FDI in China
No full textDespite the rapid expansion of U.S.-China trade ties, the increase in U.S. FDI in China, and the expanding amount of economic research exploring these developments, a number of misconceptions distort the popular understanding of U.S. multinationals in China. In this paper, we seek to correct four common misunderstandings by providing a statistical portrait of several aspects of U.S. affiliate activity in the country and placing this activity in its appropriate economic context.
Stringer: measuring the importance of static data comparisons to detect backdoors and undocumented functionality
No full textFinding undocumented functionality in commercial off-the-shelf (COTS) device firmware is an important and challenging task. This paper proposes a new static analysis method that measures the influence individual pieces of static data (such as strings) have upon the control flow of binaries in firmware. Our method automatically identifies static data comparison functions within binaries, then labels each function's basic blocks with the set of sequences of static data that must be matched against to reach them. Then using these sets, it assigns a score to each function, which measures the extent to which the function's branching is influenced by static data. Special keywords triggering backdoor functionality will have a large impact on the program flow. This allows usto identify three authentication backdoors - two of which previously un-documented. Moreover, we show our method is effective in aiding therecovery of both previously known and proprietary text-based protocols.We have developed a tool, Stringer which implements our technique; wedemonstrate the effectiveness of our approach as well as its applicabilityto lightweight analysis by running it on a data set of 2,451,532 binariesfrom 30 different COTS device vendors
Foley catheterisation versus oral misoprostol for induction of labour in hypertensive women in India (INFORM): a multicentre, open-label, randomised controlled trial
No full textBackground
Between 62 000 and 77 000 women die annually from pre-eclampsia and eclampsia. Prompt delivery, preferably by the vaginal route, is vital for good maternal and neonatal outcomes. Two low-cost interventions—low-dose oral misoprostol tablets and transcervical Foley catheterisation—are already used in low-resource settings. We aimed to compare the relative risks and benefits of these interventions.
Methods
We undertook this multicentre, open-label, randomised controlled trial in two public hospitals in Nagpur, India. Women (aged ≥18 years) who were at 20 weeks' gestation or later with a live fetus and required delivery as a result of pre-eclampsia or hypertension were randomly assigned (1:1), via computer-generated block randomisation (block sizes of four, six, and eight) with concealment by use of opaque, sequentially numbered, sealed envelopes, to receive labour induction with either oral misoprostol 25 μg every 2 h (maximum of 12 doses) or a transcervical Foley catheter (silicone, size 18 F with 30 mL balloon). Randomisation was stratified by study centre. The catheter remained in place until active labour started, the catheter fell out, or 12 h had elapsed. If the catheter did not fall out within 12 h, induction continued with artificial membrane rupture and oxytocin, administered through a micro-drip gravity infusion set. Fetal monitoring was by intermittent auscultation. The primary outcome was vaginal birth within 24 h. Due to the nature of the interventions, masking of participants, study investigators, and care providers to group allocation was not possible. We analysed by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01801410.
Findings
Between Dec 20, 2013, and June 29, 2015, we randomly assigned 602 women to induction with misoprostol (n=302) or the Foley catheter (n=300; intention-to-treat population). Vaginal birth within 24 h was more common in women in the misoprostol group than in the Foley catheter group (172 [57·0%] vs 141 [47·0%] women; absolute risk difference 10·0%, 95% CI 2·0–17·9; p=0·0136). Rates of uterine hyperstimulation were low in both the misoprostol and Foley catheter groups (two [0·7%] vs one [0·3%] cases; absolute risk difference 0·3%, 95% CI −0·8 to 1·5; p=0·566) and neonatal deaths did not differ significantly between groups (six [2·0%] vs three [1·0%] neonatal deaths; 1·0, −1·04 to 2·97; p=0·322). 17 serious adverse events (3%) were reported during the study: one case of intrapartum convulsion and one case of disseminated intravascular coagulation (both in the Foley group); ten perinatal deaths, including two stillbirths (both in the Foley catheter group) and eight neonatal deaths (n=5 in the misoprostol group and n=3 in the Foley catheter group); and five of neonatal morbidity, comprising birth asphyxia (n=3), septicaemia (n=1), and neonatal convulsion (n=1).
Interpretation
Oral misoprostol was more effective than transcervical Foley catheterisation for induction of labour in women with pre-eclampsia or hypertension. Future studies are required to assess whether oxytocin augmentation following misoprostol can be replaced by regular doses of oral misoprostol tablets
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