Adaptation of the Kademila Routing for Tactical Networks, Journal of Telecommunications and Information Technology, 2011, nr 1

In this paper a modification of the widely used Kademlia peer-to-peer system to tactical networks is proposed. We first take a look at the available systems today to cover the range of possibilities peer-to-peer systems offer. We identify candidates for use in military networks. Then we compare two candidate systems in an environment with highly dynamic participants. The considered environment is focused on the special conditions in tactical networks. Then we give rationale for choosing Kademlia as a suitable system for tactical environments. Since Kademlia is not adapted to military networks, a modification to this system is proposed to adapt it to the special conditions encountered in this environment. We show that optimizations in the routing may lead to faster lookups by measuring the modified algorithm in a simulation of the target environment. We show also that the proposed modification can be used to extend the battery lifetime of mobile peer-to-peer nodes. Our results show that peer-to-peer systems can be used in military networks to increase their robustness. The modifications proposed to Kademlia adapt the system to the special challenges of military tactical networks

Automatic multicast IPsec by using a proactive IPsec discovery protocol and a group key management, Journal of Telekommunications and Information Technology, 2008, nr 2

Internet protocol based networking is gaining ground in armed forces, leading to a concept described by the NATO as network centric capabilities (NCC). The goal is to enable state-of-the-art, affordable and powerful electronic information services to the troops. A tighter connection of the forces is expected to further enhance the joined strike capabilities. Providing secure information exchange within groups of armed forces is one aspect of the NCC concept. Such group communication is enabled by the multicast feature of the IP technology. Security requirements are met by using the IP security (IPsec) architecture. IPsec enables secure communication between secure private networks via an unsecured public text network. While secure unicast transmission with IPsec is common, only few achievements have been made to secure multicast transmissions. The protection of multicast data traffic of a group in an automated way is described in this document. We utilize an automatic detection of IPsec devices and an efficient key management protocol to reach our aim

Treatment of active lupus nephritis with the novel immunosuppressant 15-deoxyspergualin: an open-label dose escalation study

Introduction: As the immunosuppressive potency of 15-deoxyspergualin (DSG) has been shown in the therapy of renal transplant rejection and Wegener's granulomatosis, the intention of this study was to evaluate the safety of DSG in the therapy of lupus nephritis (LN). Methods: Patients with histologically proven active LN after prior treatment with at least one immunosuppressant were treated with 0.5 mg/kg normal body weight/day DSG, injected subcutaneously for 14 days, followed by a break of one week. These cycles were repeated to a maximum of 9 times. Doses of oral corticosteroids were gradually reduced to 7.5 mg/day or lower by cycle 4. Response was measured according to a predefined decision pattern. The dose of DSG was adjusted depending on the efficacy and side effects. Results: 21 patients were included in this phase-I/II study. After the first DSG injection, one patient was excluded from the study due to renal failure. 5 patients dropped out due to adverse events or serious adverse events including fever, leukopenia, oral candidiasis, herpes zoster or pneumonia. 11/20 patients achieved partial (4) or complete responses (7), 8 were judged as treatment failures and one patient was not assessable. 12 patients completed all 9 cycles; in those patients, proteinuria decreased from 5.88g/day to 3.37g/day (P = 0.028), Selena-SLEDAI decreased from 17.6 to 11.7. In 13/20 patients, proteinuria decreased by at least 50%; in 7 patients to less than 1g/day. Conclusions: Although the number of patients was small, we could demonstrate that DSG provides a tolerably safe treatment for LN. The improvement in proteinuria encourages larger controlled trials

Observing glacier elevation changes from spaceborne optical and radar sensors – an inter-comparison experiment using ASTER and TanDEM-X data

Observations of glacier mass changes are key to understanding the response of glaciers to climate change and related impacts, such as regional runoff, ecosystem changes, and global sea-level rise. Spaceborne optical and radar sensors make it possible to quantify glacier elevation changes, and thus multi-annual mass changes, on a regional and global scale. However, estimates from a growing number of studies show a wide range of results with differences often beyond uncertainty bounds. Here, we present the outcome of a community-based inter-comparison experiment using spaceborne optical stereo (ASTER) and synthetic aperture radar interferometry (TanDEM-X) data to estimate elevation changes for defined glaciers and target periods that pose different assessment challenges. Using provided or self-processed digital elevation models (DEMs) for five test sites, 12 research groups provided a total of 97 spaceborne elevation-change datasets using various processing strategies. Validation with airborne data showed that using an ensemble estimate is promising to reduce random errors from different instruments and processing methods, but still requires a more comprehensive investigation and correction of systematic errors. We found that scene selection, DEM processing, and co-registration have the biggest impact on the results. Other processing steps, such as treating spatial data voids, differences in survey periods, or radar penetration, can still be important for individual cases. Future research should focus on testing different implementations of individual processing steps (e.g. co-registration) and addressing issues related to temporal corrections, radar penetration, glacier area changes, and density conversion. Finally, there is a clear need for our community to develop best practices, use open, reproducible software, and assess overall uncertainty in order to enhance inter-comparison and empower physical process insights across glacier elevation-change studies

Environmental predictors of species richness in forest landscapes: abiotic factors versus vegetation structure

Aim To investigate the performance and relative importance of abiotic and biotic predictors of species richness of three taxa in forest-dominated landscapes across an environmentally heterogeneous mountain region. Location Switzerland (central Europe). Methods We used a broad set of nationally available environmental predictors grouped into (1) climate, (2) topography and soil and (3) 3-D vegetation structure derived from airborne Light Detection and Ranging (LiDAR) data to spatially predict the forest species richness of vascular plants, butterflies and breeding birds. We used presence data of 212 plant, 157 butterfly and 92 bird species from multiple transect samples in > 220 1 km2 squares at elevations between 261 and 2123 m a.s.l. across 41,248 km2. We applied an ensemble modelling approach consisting of five modelling techniques and evaluated their predictive performance using the cross-validated percentage of explained variance of each predictor group separately and the combinations thereof. We investigated the relative importance and response of each predictor and partitioned the variation into independent and shared components per variable group. Results Climate performed best in predicting forest species richness across taxa. Vegetation structure particularly improved the predictions of butterfly and bird species richness, while soil pH was an important predictor for forest plant species richness. Climate appeared to be mainly indirectly related to butterfly species richness, via correlations with habitat type and structure. The strength and direction of the relationships between the predictors and species richness were taxon-specific with low cross-taxon congruence. Main conclusions The growing availability of LiDAR data offers powerful new tools for describing vegetation structure and associated animal habitat quality across large areas. This will further our understanding of niche-driven assembly processes in forest landscapes. Although climate was the dominant factor controlling species richness across taxa from different trophic levels, the taxon-specific distributional pattern and response to environmental conditions emphasize the difficulty of accounting for a range of taxa in prioritising biodiversity conservation measures

Trade-off analysis of a service-oriented and hierarchical queuing mechanism

This paper sketches a service-oriented and hierarchical queuing mechanism designed to manage radio buffers while delivering web services. The goal is avoid buffer overflow implementing a three-level queuing mechanism. The first level is the message queue which stores messages from user-facing services. At the second level, the messages are fragmented into IP packets which are stored in the packet queue. Finally, the third level is the radio buffer itself. As a result, a multi-homed node has queues for each radio, capturing the likely differences of data rate, buffer size and current usage. A prototype based on web services was tested using real military radios; VHF radios with large coverage (~20 km) but very low data rate (2.4-9.6 kbps). We analyzed the trade-offs within the system configuration, targeting at an optimal and robust radio buffer management