Conversation Exchange Dynamics: A New Signal Primitive for Computer Network Intrusion Detection

As distributed network intrusion detection systems expand to integrate hundreds and possibly thousands of sensors, managing and presenting the associated sensor data becomes an increasingly complex task. Methods of intelligent data reduction are needed to make sense of the wide dimensional variations. We present a new signal primitive we call conversation exchange dynamics (CED) that accentuates anomalies in traffic flow. This signal provides an aggregated primitive that may be used by intrusion detection systems to base detection strategies upon. Indications of the signal in a variety of simulated and actual anomalous network traffic from distributed sensor collections are presented. Specifically, attacks from the MIT Lawrence Livermore IDS data set are considered. We conclude that CED presents a useful signal primitive for assistance in conducting IDS

High-Throughput Covert Channels in Adaptive Rate Wireless Communication Systems

In this paper, we outline a novel, forward error correction-based information hiding technique for adaptive rate wireless communication systems. Specifically, we propose lever- aging the functionality of wireless local area network modulation and coding schemes (MCS) and link adaptation mechanisms to significantly increase covert channel throughput. After describing our generalized information hiding model, we detail implementa- tion of this technique within the IEEE 802.11ad, directional multi- Gigabit standard. Simulation results demonstrate the potential of the proposed techniques to develop reliable, high-throughput covert channels under multiple MCS rates and embedding techniques. Covert channel performance is evaluated in terms of the observed packet error ratio of the underlying communication system as well as the bit error ratio of the hidden data

Technology requirements of exploration beyond Neptune by solar sail propulsion

This paper provides a set of requirements for the technology development of a solar sail propelled Interstellar Heliopause Probe mission. The mission is placed in the context of other outer solar systems missions, ranging from a Kuiper Belt mission through to an Oort cloud mission. Mission requirements are defined and a detailed parametric trajectory analysis and launch date scan performed. Through analysis of the complete mission trade space a set of critical technology development requirements are identified which include an advanced lightweight composite High-Gain Antenna, a high-efficiency Ka-band travelling-wave tube amplifier and a radioisotope thermoelectric generator with power density of approximately 12 W/kg. It is also shown that the Interstellar Heliopause Probe mission necessitates the use of a spinning sail, limiting the direct application of current hardware development activities. A Kuiper Belt mission is then considered as a pre-curser to the Interstellar Heliopause Probe, while it is also shown through study of an Oort cloud mission that the Interstellar Heliopause Probe mission is the likely end-goal of any future solar sail technology development program. As such, the technology requirements identified to enable the Interstellar Heliopause Probe must be enabled through all prior missions, with each mission acting as an enabling facilitator towards the next

DRAMMS: deformable registration via attribute matching and mutual-saliency weighting

A general-purpose deformable registration algorithm referred to as ”DRAMMS” is presented in this paper. DRAMMS adds to the literature of registration methods that bridge between the traditional voxel-wise methods and landmark/feature-based methods. In particular, DRAMMS extracts Gabor attributes at each voxel and selects the optimal components, so that they form a highly distinctive morphological signature reflecting the anatomical context around each voxel in a multi-scale and multi-resolution fashion. Compared with intensity or mutual-information based methods, the high-dimensional optimal Gabor attributes render different anatomical regions relatively distinctively identifiable and therefore help establish more accurate and reliable correspondence. Moreover, the optimal Gabor attribute vector is constructed in a way that generalizes well, i.e., it can be applied to different registration tasks, regardless of the image contents under registration. A second characteristic of DRAMMS is that it is based on a cost function that weights different voxel pairs according to a metric referred to as ”mutual-saliency”, which reflects the uniqueness (reliability) of anatomical correspondences implied by the tentative transformation. As a result, image voxels do not contribute equally to the optimization process, as in most voxel-wise methods, or in a binary selection fashion, as in most landmark/feature-based methods. Instead, they contribute according to a continuously-valued mutual-saliency map, which is dynamically updated during the algorithm’s evolution. The general applicability and accuracy of DRAMMS are demonstrated by experiments in simulated images, inter-subject images, single-/multi-modality images, and longitudinal images, from human and mouse brains, breast, heart, and prostate

The Imaging X-ray Polarimetry Explorer (IXPE): Technical Overview

The Imaging X-ray Polarimetry Explorer (IXPE) will expand the information space for study of cosmic sources, by adding linear polarization to the properties (time, energy, and position) observed in x-ray astronomy. Selected in 2017 January as a NASA Astrophysics Small Explorer (SMEX) mission, IXPE will be launched into an equatorial orbit in 2021. The IXPE mission will provide scientifically meaningful measurements of the x-ray polarization of a few dozen sources in the 2-8 keV band, including polarization maps of several x-ray-bright extended sources and phase-resolved polarimetry of many bright pulsating x-ray sources

Conversation Exchange Dynamics: A New Signal Primitive for Computer Network Intrusion Detection

As distributed network intrusion detection systems expand to integrate hundreds and possibly thousands of sensors, managing and presenting the associated sensor data becomes an increasingly complex task. Methods of intelligent data reduction are needed to make sense of the wide dimensional variations. We present a new signal primitive we call conversation exchange dynamics (CED) that accentuates anomalies in traffic flow. This signal provides an aggregated primitive that may be used by intrusion detection systems to base detection strategies upon. Indications of the signal in a variety of simulated and actual anomalous network traffic from distributed sensor collections are presented. Specifically, attacks from the MIT Lawrence Livermore IDS data set are considered. We conclude that CED presents a useful signal primitive for assistance in conducting IDS

Risk Factors for Cervical Pain in F-15C Pilots

INTRODUCTION: Many fighter pilots report cervical pain during their careers. Etiology likely relates to +Gz exposure, physical positioning with maneuvers, and varying load associated with headgear. We evaluated whether selected risk factors predicted cervical pain in this population. METHODS: An Institutional Review Board-approved, Health Insurance Portability and Accountability Act-compliant, controlled crossover study of the use of home cervical traction was undertaken with 20 male F-15C pilots. We recorded pilot age (mean 38 yr, range 34 - 49), total high-G hours (2338 h, range 1038 - 4645), and previous neck problems and measured cervical range of motion. For 12 wk, pilots logged pre - and postflight pain, whether the Joint Helmet Mounted Cueing System (JHMCS) was employed, maximum +Gz experienced, and sortie duration. Pain with and without JHMCS was compared using paired t-tests and correlations assessed with Pearson or Spearman coefficients. RESULTS: Mean flight - related pain increased by 0.73 on the numerical rating scale with JHMCS and 0.52 without. Neck extension coupled with JHMCS use correlated negatively with increased pain (r = - 20.551). Higher numbers of previously reported neck problems correlated with pain when using JHMCS (r = 0.629). Age, maximum +Gz per sortie, total high-Gz hours flown, and hours per sortie did not correlate. DISCUSSION: To our knowledge, this is the first prospective evaluation of risk factors for fighter pilots\u27 cervical pain. Neck pain was significantly worse with JHMCS use and with flexed posture or history of prior neck problems combined with JHMCS use. This information will help guide countermeasure development for high-G pilots

Risk Factors for Cervical Pain in F-15C Pilots

INTRODUCTION: Many fighter pilots report cervical pain during their careers. Etiology likely relates to +Gz exposure, physical positioning with maneuvers, and varying load associated with headgear. We evaluated whether selected risk factors predicted cervical pain in this population. METHODS: An Institutional Review Board-approved, Health Insurance Portability and Accountability Act-compliant, controlled crossover study of the use of home cervical traction was undertaken with 20 male F-15C pilots. We recorded pilot age (mean 38 yr, range 34 - 49), total high-G hours (2338 h, range 1038 - 4645), and previous neck problems and measured cervical range of motion. For 12 wk, pilots logged pre - and postflight pain, whether the Joint Helmet Mounted Cueing System (JHMCS) was employed, maximum +Gz experienced, and sortie duration. Pain with and without JHMCS was compared using paired t-tests and correlations assessed with Pearson or Spearman coefficients. RESULTS: Mean flight - related pain increased by 0.73 on the numerical rating scale with JHMCS and 0.52 without. Neck extension coupled with JHMCS use correlated negatively with increased pain (r = - 20.551). Higher numbers of previously reported neck problems correlated with pain when using JHMCS (r = 0.629). Age, maximum +Gz per sortie, total high-Gz hours flown, and hours per sortie did not correlate. DISCUSSION: To our knowledge, this is the first prospective evaluation of risk factors for fighter pilots\u27 cervical pain. Neck pain was significantly worse with JHMCS use and with flexed posture or history of prior neck problems combined with JHMCS use. This information will help guide countermeasure development for high-G pilots