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Adam Bates Benjamin Mood Joe Pletcher Hannah Pruse Masoud Valafar Kevin Butler 《International Journal of Information Security》2014,13(2):171-189
Virtualization is the cornerstone of the developing third-party compute industry, allowing cloud providers to instantiate multiple virtual machines (VMs) on a single set of physical resources. Customers utilize cloud resources alongside unknown and untrusted parties, creating the co-resident threat—unless perfect isolation is provided by the virtual hypervisor, there exists the possibility for unauthorized access to sensitive customer information through the exploitation of covert side channels. This paper presents co-resident watermarking, a traffic analysis attack that allows a malicious co-resident VM to inject a watermark signature into the network flow of a target instance. This watermark can be used to exfiltrate and broadcast co-residency data from the physical machine, compromising isolation without reliance on internal side channels. As a result, our approach is difficult to defend against without costly underutilization of the physical machine. We evaluate co-resident watermarkingunder a large variety of conditions, system loads and hardware configurations, from a local laboratory environment to production cloud environments (Futuregrid and the University of Oregon’s ACISS). We demonstrate the ability to initiate a covert channel of 4 bits per second, and we can confirm co-residency with a target VM instance in $<$ 10 s. We also show that passive load measurement of the target and subsequent behavior profiling is possible with this attack. We go on to consider the detectability of co-resident watermarking, extending our scheme to create a subtler watermarking attack by imitating legitimate cloud customer behavior. Our investigation demonstrates the need for the careful design of hardware to be used in the cloud. 相似文献
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Manibarathi Vaithiyanathan Hannah C. Hymel Nora Safa Olivia M. Sanchez Jacob H. Pettigrew Cole S. Kirkpatrick Ted J. Gauthier Adam T. Melvin 《American Institute of Chemical Engineers》2021,67(1):e17087
Most cell penetrating peptides (CPPs) are unstructured and susceptible to proteolytic degradation. One alternative is to incorporate D-chirality amino acids into unstructured CPPs to allow for enhanced uptake and intracellular stability. This work investigates CPP internalization using a series of time, concentration, temperature, and energy dependent studies, resulting in a three-fold increase in uptake and 50-fold increase in stability of D-chirality peptides over L-chirality counterparts. CPP internalization occurred via a combination of direct penetration and endocytosis, with a percentage of internalized CPP expelling from cells in a time-dependent manner. Mechanistic studies identified that cells exported the intact internalized D-chirality CPPs via an exocytosis independent pathway, analogous to a direct penetration method out of the cells. These findings highlight the potential of a D-chirality CPP as bio-vector in therapeutic and biosensing applications, but also identify a new expulsion method suggesting a relationship between uptake kinetics, intracellular stability, and export kinetics. 相似文献
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ABSTRACT Librarians at Oregon State University (OSU) Libraries used the discussion board features of Blackboard courseware to create an interactive experience for graduate students at a distance who could not attend the on-campus “Literature Review Workshops.” These recently developed workshops have been extremely popular with graduate students across the disciplines and have generated a growing demand from distance education graduate students and faculty to offer similar information online. Reluctant to simply deliver content via an online tutorial, librarians sought to duplicate the workshop atmosphere by making the sessions available for a short time-period online, asking participants to respond to discussion questions at specific points in the workshop, and offering audio-mediated online demonstrations of tools and resources. Student feedback and follow-up requests for more workshops support the perception that this approach offered a rewarding learning experience that addressed their specific adult learning needs. 相似文献
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Hannah Grainger Clemson 《Digital Creativity》2013,24(4):330-342
AbstractWith a growing number of embedded digital experiences in arts and heritage settings, creating a broad global field, this article focuses on the use of mobile phones in the engagement of humans with the cultural heritage of public spaces, specifically those that require a promenade from one outdoor space to another. This article discusses findings from a recent promenade initiative, commissioned for a UK arts festival, along with a review of literature, to critically engage with growing evidence of the diverse ways in which technology is integrated at direct user level. Concepts of ‘hybrid spaces’ and ‘user agency’ are discussed, along with the ‘performativity’ of spaces. Central to the discussion is the function of narrative in engaging the participant to construct new perspectives, which are facilitated by the mediating role of personal media devices between subject, narrative, space and community. 相似文献
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Robert Hannah 《Nexus Network Journal》2013,15(3):423-443
The study of the orientation of ancient structures has recently experienced a renaissance in scientific interest after languishing for much of the twentieth century. Under the umbrella of the new multi-discipline of archaeoastronomy, the analyses of orientations have become more sophisticated, with a wider range of celestial phenomena now included, along with information derived from cult myths and rituals, so that celestial phenomena are identified through being relevant on a local, cultural and cultic level. Ironically, this revival of interest in temple orientations largely matches in its methodology that of Dinsmoor [1931], yet his work has lost favour because of his insistence on the priority of solar phenomena. In this paper, I revisit Dinsmoor’s analysis of one temple, the Older Parthenon in Athens, to assess his methodology and conclusions. 相似文献
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Oxidative Stress Imaging: Visualizing Oxidative Cellular Stress Induced by Nanoparticles in the Subcytotoxic Range Using Fluorescence Lifetime Imaging (Small 23/2018) 下载免费PDF全文
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We propose a new method that treats visible human behaviour at the level of navigational strategies. By inferring intentions in terms of known goals, it is possible to explain the behaviour of people moving around within the field of view of a video camera. The approach presented here incorporates models of navigation from within psychology which are both simple and conceptually plausible, whilst providing good results in an event-detection application. The output is in the form of statements involving goals, such as “Agent 25 went to exit 8 via sub-goals 34 and 21” for a given navigational strategy, an image representing the path through the scene, and an overall score for each trajectory. The central algorithm generates all plausible paths through the scene to known goal sites and then compares each path to the agent's actual trajectory thus finding the most likely explanation for their behaviour. Two navigational strategies are examined, shortest path and simplest path. Experimental results are presented for an outdoor car-park and an indoor foyer scene, and our method is found to produce psychologically plausible explanations in the majority of cases. We propose a novel approach to determining the effectiveness of event detection systems, and evaluate the method presented here against this new ground truth. This evaluation method uses human observers to judge the behaviour shown in various video clips, then uses these judgements in correlation with those of the software. We compare the method with a standard machine learning approach based on nearest neighbour. Finally we consider the application of such a system in a binary event-detection or behaviour filtering system. 相似文献
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