1,561 research outputs found

    TANDI: Threat Assessment of Network Data and Information

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    Current practice for combating cyber attacks typically use Intrusion Detection Sensors (IDSs) to passively detect and block multi-stage attacks. This work leverages Level-2 fusion that correlates IDS alerts belonging to the same attacker, and proposes a threat assessment algorithm to predict potential future attacker actions. The algorithm, TANDI, reduces the problem complexity by separating the models of the attacker\u27s capability and opportunity, and fuse the two to determine the attacker\u27s intent. Unlike traditional Bayesian-based approaches, which require assigning a large number of edge probabilities, the proposed Level-3 fusion procedure uses only 4 parameters. TANDI has been implemented and tested with randomly created attack sequences. The results demonstrate that TANDI predicts future attack actions accurately as long as the attack is not part of a coordinated attack and contains no insider threats. In the presence of abnormal attack events, TANDI will alarm the network analyst for further analysis. The attempt to evaluate a threat assessment algorithm via simulation is the first in the literature, and shall open up a new avenue in the area of high level fusion

    Evaluating Threat Assessment for Multi-Stage Cyber Attacks

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    Current practices to defend against cyber attacks are typically reactive yet passive. Recent research work has been proposed to proactively predict hacker\u27s target entities in the early stage of the attack. With prediction, there comes false alarms and missed attacks. Very little has been reported on how to evaluate a threat assessment algorithm, especially for cyber security. Because of the variety and the constantly changing nature of hacker behavior and network vulnerabilities, a cyber threat assessment algorithm is, perhaps more susceptible that for other application domains. This work sets forth the issues on evaluating cyber threat assessment algorithms, and discusses the validity of various statistical measures. Simulation examples are provided to illustrate the pros and cons of using different metrics under various cyber attack scenarios. Our results show that commonly used false positives and false negatives are necessary but not sufficient to evaluate cyber threat assessment

    Mississippi Kids Count: High School Graduation Rates

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    Though national dropout rates have generally fallen over the past twenty years, almost 1.2 million students in the United States drop out of school each year, representing nearly one-third of high school students. At about 61%, Mississippi’s high school graduation rate falls slightly below the national figure, though school districts in the Mississippi Delta fare particularly poorly. Five of the ten districts with the highest four-year dropout rates in the state are located in Delta region counties: Leflore, Tallahatchie, Sunflower, Tunica, and Panola Counties

    Terrain and Behavior Modeling for Projecting Multistage Cyber Attacks

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    Contributions from the information fusion community have enabled comprehensible traces of intrusion alerts occurring on computer networks. Traced or tracked cyber attacks are the bases for threat projection in this work. Due to its complexity, we separate threat projection into two subtasks: predicting likely next targets and predicting attacker behavior. A virtual cyber terrain is proposed for identifying likely targets. Overlaying traced alerts onto the cyber terrain reveals exposed vulnerabilities, services, and hosts. Meanwhile, a novel attempt to extract cyber attack behavior is discussed. Leveraging traditional work on prediction and compression, this work identifies behavior patterns from traced cyber attack data. The extracted behavior patterns are expected to further refine projections deduced from the cyber terrain

    Probing Disk Ice Content and PAH Emission Through Multiband MagAO+Clio Images of HD 141569

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    We present resolved images of the inner disk component around HD 141569 using the Magellan adaptive optics system with the Clio2 1 - 5 μ\mum camera, offering a glimpse of a complex system thought to be in a short evolutionary phase between protoplanetary and debris disk stages. We use a reference star along with the KLIP algorithm for PSF subtraction to detect the disk inward to about 0.24" (~25 au assuming a distance of 111 pc) at high signal-to-noise ratios at L′L' (3.8 μ\mum), LsLs (3.3 μ\mum), and narrowband IceIce (3.1 μ\mum). We identify an arc or spiral arm structure at the southeast extremity, consistent with previous studies. We implement forward modeling with a simple disk model within the framework of an MCMC sampler to better constrain the geometrical attributes and photometry using our KLIP-reduced disk images. We then leverage these modeling results to facilitate a comparison of the measured brightness in each passband to find a reduction in scattered light from the disk in the IceIce filter, implying significant absorption due to water ice in the dust. Additionally, our best-fit disk models exhibit peak brightness in the southwestern, back-scattering region of the disk, which we suggest to be possible evidence of 3.3 μ\mum PAH emission. However, we point out the need for additional observations with bluer filters and more complex modeling to confirm these hypotheses.Comment: Accepted for publication in The Astrophysical Journal, 22 pages, 11 Figures, 5 Tables, 1 Appendi

    SWIR Emissive RosIndolizine Dyes With Nanoencapsulation In Water Soluble Dendrimers

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    Shortwave infrared (SWIR) emission has great potential for deep-tissue in vivo biological imaging with high resolution. In this article, the synthesis and characterization of two new xanthene-based RosIndolizine dyes coded PhRosIndz and tolRosIndz is presented. The dyes are characterized via femtosecond transient absorption spectroscopy as well as steady-state absorption and emission spectroscopies. The emission of these dyes is shown in the SWIR region with peak emission at 1097 nm. TolRosIndz was encapsulated with an amphiphilic linear dendritic block co-polymer (LDBC) coded 10-PhPCL-G3 with high uptake yield. Further, cellular toxicity was examined in vitro using HEK (human embryonic kidney) cells where a \u3e90% cell viability was observed at practical concentrations of the encapsulated dye which indicates low toxicity and reasonable biocompatibility

    Predictors of Nerve Stimulator Success in Patients With Overactive Bladder

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    Purpose To identify factors associated with successful sacral nerve stimulator (SNS) trial after SNS implantation for the treatment of medication refractory overactive bladder (OAB). Methods Patients undergoing treatment for OAB at Lahey Hospital and Medical Center between 2004 and 2016 were identified. Patients undergoing SNS placement were identified; SNS success was defined as permanent implantation of the SNS. Demographic, clinical and treatment data were extracted from patient charts; uni- and multivariate analyses were conducted to identify factors associated with SNS treatment success. Results A total of 128 patients were included. On univariate analysis, male sex, prior diagnosis of benign prostatic hyperplasia, and lower volume at first urge on urodynamics (UDS) were associated with unsuccessful SNS trial. On multivariate analysis, male sex (odds ratio [OR], 0.145; 95% confidence interval [CI], 0.036–0.530) and lower volume at first urge on UDS (OR, 0.982; 95% CI, 0.967–0.995) were associated with unsuccessful SNS trial. A threshold value of 100 mL at first urge during preoperative UDS had a specificity of 0.86 in predicting SNS success in men. Conclusions SNS is frequently successful at relieving OAB symptoms. Male patients and those with lower volumes at first urge on UDS, particularly below 100 mL, are more likely to have an unsuccessful SNS trial. Patients in these groups should be counseled on the lower likelihood of SNS success
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