Abstract-An integral part of most security-and safety-critical applications is a dependable and timely alarm notification. However, owing to the resource constraints of wireless sensor nodes (i.e., their limited power and spectral diversity), ensuring a timely and jamming-resistant delivery of alarm messages in applications that rely on wireless sensor networks is a challenging task. With current alarm forwarding schemes, blocking of an alarm by jamming is straightforward and jamming is very likely to remain unnoticed. In this work, we propose a novel jamming detection scheme as a solution to this problem. Our scheme is able to identify the cause of bit errors for individual packets by looking at the received signal strength during the reception of these bits and is well-suited for the protection of reactive alarm systems with very low network traffic. We present three different techniques for the identification of bit errors based on: predetermined knowledge, error correcting codes, and limited node wiring. We perform a detailed evaluation of the proposed solution and validate our findings experimentally with Chipcon CC1000 and CC2420 radios. The results show that our solution effectively detects sophisticated jamming attacks that cannot be detected with existing techniques and enables the formation of robust sensor networks for dependable delivery of alarm notifications. Our scheme also meets the high demands on the energy efficiency of reactive surveillance applications as it can operate without introducing additional wireless network traffic.
Summary
Homogenous grape material of the red varieties c.v. Pinot noir, c.v. Dornfelder and c.v. Portugieser were fermented on an industrial scale using a special fermenter for pump over and punch down treatment. On pilot scale, thermovinfication was carried out at 60 °C and a manual punch down treatment was used in open containers. Both the mechanical punch down and pump over treatment significantly enhanced the extraction of all phenolic compounds and their polymerization in comparison to the traditional manual punch down treatment. Applying an excess of mechanical maceration increased the extraction of seed and stem phenols, but slowed down their polymerization. Assessing volatile composition, the biggest differences occurred between wines made by thermovinification versus those fermented on their skins. Slow fermentation kinetics and low solid content in the juice enhanced ester formation in thermovinied wines. Thermal inactivation of lipoxygenase enzyme systems reduced C6‐alcohols and their subsequent esters in thermovinified wines. Only small differences occurred between punch down and pump over tanks except that the pump over regime gave all varieties of wines significantly higher quercetin levels. In conclusion, the application of modern fermentation equipment seemed to be more relevant to improve extraction and polymerization of phenolic compounds, while thermovinification yielded wines with high ester content giving a more fruity style.
Abstract. When developing and researching new trusted computing technologies, appropriate tools to investigate their behavior and to evaluate their performance are of paramount importance. In this paper, we present an efficient and portable TPM emulator for Unix. Our emulator enables not only the implementation of flexible and low-cost test-beds and simulators but, in addition, provides programmers of trusted systems with a powerful testing and debugging tool that can also be used for educational purposes. Thanks to its portability and interoperability, the TPM emulator runs on a variety of platforms and is compatible with the most relevant software packages and interfaces.
Abstract. We present a protocol that allows servers to securely distribute secrets to trusted platforms. The protocol maintains the confidentiality of secrets in the face of eavesdroppers and careless users. Given an ideal (tamper-proof) trusted platform, the protocol can even withstand attacks by dishonest users. As an example of its use, we present an application to secure document processing.
Abstract. With the field of wireless sensor networks rapidly maturing, the focus shifts from "easy" deployments, like remote monitoring, to more difficult domains where applications impose strict, real-time constraints on performance. One such class of applications is safety critical systems, like fire and burglar alarms, where events detected by sensor nodes have to be reported reliably and timely to a sink node. A complicating factor is that systems must operate for years without manual intervention, which puts very strong demands on the energy efficiency of protocols running on current sensor-node platforms.Since we are not aware of a solution that meets all requirements of safety-critical systems, i.e. provides reliable data delivery and low latency and low energy consumption, we present Dwarf, an energy-efficient, robust and dependable forwarding algorithm. The core idea is to use unicast-based partial flooding along with a delay-aware node selection strategy. Our analysis and extensive simulations of real-world scenarios show that Dwarf tolerates large fractions of link and node failures, yet is energy efficient enough to allow for an operational lifetime of several years.
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