37 research outputs found

    Coupling highly excited nuclei to the atomic shell in dense astrophysical plasmas

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    In dense astrophysical plasmas, neutron capture populates highly excited nuclear states close to the neutron threshold. The impact of additional low-energy nuclear excitations via coupling to the atomic shell on the ability of the so-formed compound nucleus to retain the captured neutron is investigated. We focus on the mechanism of nuclear excitation by electron capture in plasmas characterized by electron fluxes typical for the slow neutron capture process of stellar nucleosynthesis. The small effect of this further excitation on the neutron capture and gamma decay sequence relevant for nucleosynthesis is quantified and compared to the corresponding effect of an additional low-energy photoexcitation step.Comment: 11 pages, 10 figures; v2 minor modifications to match the published version, results unchange

    Using Global Honeypot Networks to Detect Targeted ICS Attacks

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    Defending industrial control systems (ICS) in the cyber domain is both helped and hindered by bespoke systems integrating heterogeneous devices for unique purposes. Because of this fragmentation, observed attacks against ICS have been targeted and skilled, making them difficult to identify prior to initiation. Furthermore, organisations may be hesitant to share business-sensitive details of an intrusion that would otherwise assist the security community. In this work, we present the largest study of high-interaction ICS honeypots to date and demonstrate that a network of internet-connected honeypots can be used to identify and profile targeted ICS attacks. Our study relies on a network of 120 high-interaction honeypots in 22 countries that mimic programmable logic controllers and remote terminal units. We provide a detailed analysis of 80,000 interactions over 13 months, of which only nine made malicious use of an industrial protocol. Malicious interactions included denial of service and replay attacks that manipulated logic, leveraged protocol implementation gaps and exploited buffer overflows. While the yield was small, the impact was high, as these were skilled, targeted exploits previously unknown to the ICS community. By comparison with other ICS honeypot studies, we demonstrate that high-quality deception over long periods is necessary for such a honeypot network to be effective. As part of this argument, we discuss the accidental and intentional reasons why an internet-connected honeypot might be targeted. We also provide recommendations for effective, strategic use of such networks.Gates Cambridge Trus

    OMAE2007-29202 C-MANIPULATOR: AN AUTONOMOUS DUAL MANIPULATOR PROJECT FOR UNDERWATER INSPECTION AND MAINTENANCE

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    ABSTRACT We present the new project C-Manipulator (funded by the German Ministry of Economics (BMWI), Grant No. 03SX231). The goal of C

    Webserver-Sicherheit mit mod_security

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    A Hybrid Locomotion Control Approach

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    This paper presents the joint control part of a new hybrid locomotion control concept which is developed in the walking robot project ARAMIES . The concept is based on a CPG-model (implemented with Bezier-splines), a reflex model inspired by artificial neurons, and a posture control model. It has been successfully tested on the 8-legged walking robot SCORPIO

    Exploration of Underwater Structures with Cooperative Heterogeneous Robots

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    This paper describes ideas in the field of cooperative underwater robotics, which can considerably enhance the exploration capabilities of underwater robots. Three heterogeneous planned or existing underwater robots are presented and possible approaches for cooperative behavior are discussed. Possible application scenarios for future deployment are presented

    Embodied Categorization of Spatial Environments on the Basis of Proprioceptive Data

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    This article describes research on the usability of proprioceptive data for spatial categorization. A first experiment was carried out using the 8-legged robot SCORPION, which provides us with a multitude of proprioceptive sensors. We present how these signals can be used in our biomimetic approach to learn on which substrates the robot is moving. Results are presented from runs carried out on our experimental indoor test bed, which contains different substrates, e.g., sand, rocks and gravel. To classify the proprioceptive sensor data, a supervised learning approach based on the growing cell structure learning algorithm is used. The gained results are discussed and next steps are motivated

    Stability of Walking in a Multilegged Robot Suffering Leg Loss

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    This article describes tests of fault tolerance of the eight-legged walking robot SCORPION in the event of leg loss. It evaluates different gaits, which are based on biological research on insect and arachnid walking and concludes with a discussion, what the best gait for the SCORPION system is, when 2 legs are lost. It also includes a short introduction to the SCORPION robot and its biomimetic software approach and its performance in different terrain

    AIMEE: A Four-Legged Robot for RoboCup Rescue

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    This paper presents a servo-based Four-Legged robot -- named AIMEE -- for the RoboCup Rescue competition (see [1] for details
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