70 research outputs found

    First results of the air shower experiment KASCADE

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    The main goals of the KASCADE (KArlsruhe Shower Core and Array DEtector) experiment are the determination of the energy spectrum and elemental composition of the charged cosmic rays in the energy range around the knee at ca. 5 PeV. Due to the large number of measured observables per single shower a variety of different approaches are applied to the data, preferably on an event-by-event basis. First results are presented and the influence of the high-energy interaction models underlying the analyses is discussed.Comment: 3 pages, 3 figures included, to appear in the TAUP 99 Proceedings, Nucl. Phys. B (Proc. Suppl.), ed. by M. Froissart, J. Dumarchez and D. Vignau

    Electron, Muon, and Hadron Lateral Distributions Measured in Air-Showers by the KASCADE Experiment

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    Measurements of electron, muon, and hadron lateral distributions of extensive air showers as recorded by the KASCADE experiment are presented. The data cover the energy range from about 5x10^14 eV up to almost 10^17 eV and extend from the inner core region to distances of 200 m. The electron and muon distributions are corrected for mutual contaminations by taking into account the detector properties in the experiment. All distributions are well described by NKG-functions. The scale radii describing the electron and hadron data best are approx. 30 m and 10 m, respectively. We discuss the correlation between scale radii and `age' parameter as well as their dependence on shower size, zenith angle, and particle energy threshold.Comment: 28 pages, 14 figures, Accepted for publication in Astroparticle Physic

    Cosmic ray physics around the knee with the KASCADE experiment

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    KASCADE (KArlsruhe Shower Core and Array DEtector) is a multidetector setup to observe the electromagnetic, muonic and hadronic air shower components simultaneously for the primary energy region around the knee. The large body of observables per single shower allows to follow the main aims of the experiment in analyses on an event-by-event basis, mainly: 1) slopes and structures of the primary energy spectrum; 2) the energy dependence of the chemical composition of the primaries; 3) tests of the air shower simulation tools underlying the analyses, in particular of the Monte Carlo generators based on different high-energy interaction models; 4) examinations of the air shower development in the atmosphere. Examples and results of different analysis methods are presented for the different subjects

    Optimizing investments in cyber hygiene for protecting healthcare users

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    Cyber hygiene measures are often recommended for strengthening an organization’s security posture, especially for protecting against social engineering attacks that target the human element. However, the related recommendations are typically the same for all organizations and their employees, regardless of the nature and the level of risk for different groups of users. Building upon an existing cybersecurity investment model, this paper presents a tool for optimal selection of cyber hygiene safeguards, which we refer as the Optimal Safeguards Tool (OST). The model combines game theory and combinatorial optimization (0-1 Knapsack) taking into account the probability of each user group to being attacked, the value of assets accessible by each group, and the efficacy of each control for a particular group. The model considers indirect cost as the time employees could require for learning and trainning against an implemented control. Utilizing a game-theoretic framework to support the Knapsack optimization problem permits us to optimally select safeguards’ application levels minimizing the aggregated expected damage within a security investment budget. We evaluate OST in a healthcare domain use case. In particular, on the Critical Internet Security (CIS) Control group 17 for implementing security awareness and training programs for employees belonging to the ICT, clinical and administration personnel of a hospital. We compare the strategies implemented by OST against alternative common-sense defending approaches for three different types of attackers: Nash, Weighted and Opportunistic. Our results show that Nash defending strategies are consistently better than the competing strategies for all attacker types with a minor exception where the Nash defending strategy, for a specific game, performs at least as good as other common-sense approaches. Finally, we illustrate the alternative investment strategies on different Nash equilibria (called plans) and discuss the optimal choice using the framework of 0-1 Knapsack optimization

    Wound dressings for a proteolytic-rich environment

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    Wound dressings have experienced continuous and significant changes over the years based on the knowledge of the biochemical events associated with chronic wounds. The development goes from natural materials used to just cover and conceal the wound to interactive materials that can facilitate the healing process, addressing specific issues in non-healing wounds. These new types of dressings often relate with the proteolytic wound environment and the bacteria load to enhance the healing. Recently, the wound dressing research is focusing on the replacement of synthetic polymers by natural protein materials to delivery bioactive agents to the wounds. This article provides an overview on the novel protein-based wound dressings such as silk fibroin keratin and elastin. The improved properties of these dressings, like the release of antibiotics and growth factors, are discussed. The different types of wounds and the effective parameters of healing process will be reviewed
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