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Fast online learning of antijamming and jamming strategies

Summary

Competing Cognitive Radio Network (CCRN) coalesces communicator (comm) nodes and jammers to achieve maximal networking efficiency in the presence of adversarial threats. We have previously developed two contrasting approaches for CCRN based on multi-armed bandit (MAB) and Qlearning. Despite their differences, both approaches have shown to achieve optimal throughput performance. This paper addresses a harder class of problems where channel rewards are time-varying such that learning based on stochastic assumptions cannot guarantee the optimal performance. This new problem is important because an intelligent adversary will likely introduce dynamic changepoints, which can make our previous approaches ineffective. We propose a new, faster learning algorithm using online convex programming that is computationally simpler and stateless. According to our empirical results, the new algorithm can almost instantly find an optimal strategy that achieves the best steady-state channel rewards.
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Summary

Competing Cognitive Radio Network (CCRN) coalesces communicator (comm) nodes and jammers to achieve maximal networking efficiency in the presence of adversarial threats. We have previously developed two contrasting approaches for CCRN based on multi-armed bandit (MAB) and Qlearning. Despite their differences, both approaches have shown to achieve optimal throughput performance...

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The MITLL-AFRL IWSLT 2015 Systems

Summary

This report summarizes the MITLL-AFRL MT, ASR and SLT systems and the experiments run using them during the 2015 IWSLT evaluation campaign. We build on the progress made last year, and additionally experimented with neural MT, unknown word processing, and system combination. We applied these techniques to translating Chinese to English and English to Chinese. ASR systems are also improved by reining improvements developed last year. Finally, we combine our ASR and MT systems to produce a English to Chinese SLT system.
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Summary

This report summarizes the MITLL-AFRL MT, ASR and SLT systems and the experiments run using them during the 2015 IWSLT evaluation campaign. We build on the progress made last year, and additionally experimented with neural MT, unknown word processing, and system combination. We applied these techniques to translating Chinese to...

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Spyglass: demand-provisioned Linux containers for private network access

Published in:
Proc. 29th Large Installation System Administration Conf., LISA, 8-13 November 2015.

Summary

System administrators are required to access the privileged, or "super-user," interfaces of computing, networking, and storage resources they support. This low-level infrastructure underpins most of the security tools and features common today and is assumed to be secure. A malicious system administrator or malware on the system administrator's client system can silently subvert this computing infrastructure. In the case of cloud system administrators, unauthorized privileged access has the potential to cause grave damage to the cloud provider and their customers. In this paper, we describe Spyglass, a tool for managing, securing, and auditing administrator access to private or sensitive infrastructure networks by creating on-demand bastion hosts inside of Linux containers. These on-demand bastion containers differ from regular bastion hosts in that they are nonpersistent and last only for the duration of the administrator's access. Spyglass also captures command input and screen output of all administrator activities from outside the container, allowing monitoring of sensitive infrastructure and understanding of the actions of an adversary in the event of a compromise. Through our evaluation of Spyglass for remote network access, we show that it is more difficult to penetrate than existing solutions, does not introduce delays or major workflow changes, and increases the amount of tamper-resistant auditing information that is captured about a system administrator's access.
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Summary

System administrators are required to access the privileged, or "super-user," interfaces of computing, networking, and storage resources they support. This low-level infrastructure underpins most of the security tools and features common today and is assumed to be secure. A malicious system administrator or malware on the system administrator's client system...

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Improved hidden clique detection by optimal linear fusion of multiple adjacency matrices

Published in:
2015 Asilomar Conf. on Signals, Systems and Computers, 8-11 November 2015.

Summary

Graph fusion has emerged as a promising research area for addressing challenges associated with noisy, uncertain, multi-source data. While many ad-hoc graph fusion techniques exist in the current literature, an analytical approach for analyzing the fundamentals of the graph fusion problem is lacking. We consider the setting where we are given multiple Erdos-Renyi modeled adjacency matrices containing a common hidden or planted clique. The objective is to combine them linearly so that the principal eigenvectors of the resulting matrix best reveal the vertices associated with the clique. We utilize recent results from random matrix theory to derive the optimal weighting coefficients and use these insights to develop a data-driven fusion algorithm. We demonstrate the improved performance of the algorithm relative to other simple heuristics.
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Summary

Graph fusion has emerged as a promising research area for addressing challenges associated with noisy, uncertain, multi-source data. While many ad-hoc graph fusion techniques exist in the current literature, an analytical approach for analyzing the fundamentals of the graph fusion problem is lacking. We consider the setting where we are...

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Residuals-based subgraph detection with cue vertices

Published in:
2015 Asilomar Conf. on Signals, Systems and Computers, 8-11 November 2015.

Summary

A common problem in modern graph analysis is the detection of communities, an example of which is the detection of a single anomalously dense subgraph. Recent results have demonstrated a fundamental limit for this problem when using spectral analysis of modularity. In this paper, we demonstrate the implication of these results on subgraph detection when a cue vertex is provided, indicating one of the vertices in the community of interest. Several recent algorithms for local community detection are applied in this context, and we compare their empirical performance to that of the simple method used to derive the theoretical detection limits.
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Summary

A common problem in modern graph analysis is the detection of communities, an example of which is the detection of a single anomalously dense subgraph. Recent results have demonstrated a fundamental limit for this problem when using spectral analysis of modularity. In this paper, we demonstrate the implication of these...

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Sampling operations on big data

Published in:
2015 Asilomar Conf. on Signals, Systems and Computers, 8-11 November 2015.

Summary

The 3Vs -- Volume, Velocity and Variety -- of Big Data continues to be a large challenge for systems and algorithms designed to store, process and disseminate information for discovery and exploration under real-time constraints. Common signal processing operations such as sampling and filtering, which have been used for decades to compress signals are often undefined in data that is characterized by heterogeneity, high dimensionality, and lack of known structure. In this article, we describe and demonstrate an approach to sample large datasets such as social media data. We evaluate the effect of sampling on a common predictive analytic: link prediction. Our results indicate that greatly sampling a dataset can still yield meaningful link prediction results.
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Summary

The 3Vs -- Volume, Velocity and Variety -- of Big Data continues to be a large challenge for systems and algorithms designed to store, process and disseminate information for discovery and exploration under real-time constraints. Common signal processing operations such as sampling and filtering, which have been used for decades...

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Percolation model of insider threats to assess the optimum number of rules

Published in:
Environ. Syst. Decis., Vol. 35, 2015, pp. 504-10.

Summary

Rules, regulations, and policies are the basis of civilized society and are used to coordinate the activities of individuals who have a variety of goals and purposes. History has taught that over-regulation (too many rules) makes it difficult to compete and under-regulation (too few rules) can lead to crisis. This implies an optimal number of rules that avoids these two extremes. Rules create boundaries that define the latitude at which an individual has to perform their activities. This paper creates a Toy Model of a work environment and examines it with respect to the latitude provided to a normal individual and the latitude provided to an insider threat. Simulations with the Toy Model illustrate four regimes with respect to an insider threat: under-regulated, possibly optimal, tipping point, and over-regulated. These regimes depend upon the number of rules (N) and the minimum latitude (Lmin) required by a normal individual to carry out their activities. The Toy Model is then mapped onto the standard 1D Percolation Model from theoretical physics, and the same behavior is observed. This allows the Toy Model to be generalized to a wide array of more complex models that have been well studied by the theoretical physics community and also show the same behavior. Finally, by estimating N and Lmin, it should be possible to determine the regime of any particular environment.
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Summary

Rules, regulations, and policies are the basis of civilized society and are used to coordinate the activities of individuals who have a variety of goals and purposes. History has taught that over-regulation (too many rules) makes it difficult to compete and under-regulation (too few rules) can lead to crisis. This...

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Domain mismatch compensation for speaker recognition using a library of whiteners

Published in:
IEEE Signal Process. Lett., Vol. 22, No. 11, November 2015, pp. 2000-2003.

Summary

The development of the i-vector framework for generating low dimensional representations of speech utterances has led to considerable improvements in speaker recognition performance. Although these gains have been achieved in periodic National Institute of Standards and Technology (NIST) evaluations, the problem of domain mismatch, where the system development data and the application data are collected from different sources, remains a challenging one. The impact of domain mismatch was a focus of the Johns Hopkins University (JHU) 2013 speaker recognition workshop, where a domain adaptation challenge (DAC13) corpus was created to address this problem. This paper proposes an approach to domain mismatch compensation for applications where in-domain development data is assumed to be unavailable. The method is based on a generalization of data whitening used in association with i-vector length normalization and utilizes a library of whitening transforms trained at system development time using strictly out-of-domain data. The approach is evaluated on the 2013 domain adaptation challenge task and is shown to compare favorably to in-domain conventional whitening and to nuisance attribute projection (NAP) inter-dataset variability compensation.
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Summary

The development of the i-vector framework for generating low dimensional representations of speech utterances has led to considerable improvements in speaker recognition performance. Although these gains have been achieved in periodic National Institute of Standards and Technology (NIST) evaluations, the problem of domain mismatch, where the system development data and...

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Unlocking user-centered design methods for building cyber security visualizations(3.93 MB)

Published in:
Proceedings of 2015 IEEE Symposium on Visualization for Cyber Security (VizSec)

Summary

User-centered design can aid visualization designers to build better, more practical tools that meet the needs of cyber security users. In this paper, we discuss three design methods and illustrate how each method informed two real-world cyber security visualization projects which resulted in successful deployments to users.
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Summary

User-centered design can aid visualization designers to build better, more practical tools that meet the needs of cyber security users. In this paper, we discuss three design methods and illustrate how each method informed two real-world cyber security visualization projects which resulted in successful deployments to users.

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VAST Challenge 2015: Mayhem at Dinofun World(757.94 KB)

Published in:
Proceedings of 2015 IEEE Conference on Visual Analytics Science and Technology (VAST)

Summary

A fictitious amusement park and a larger-than-life hometown football hero provided participants in the VAST Challenge 2015 with an engaging yet complex storyline and setting in which to analyze movement and communication patterns.
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Summary

A fictitious amusement park and a larger-than-life hometown football hero provided participants in the VAST Challenge 2015 with an engaging yet complex storyline and setting in which to analyze movement and communication patterns.

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