Safety,Security, and Rescue Missions with an Unmanned Aerial Vehicle (UAV)

Several missions with an Unmanned Aerial Vehicle (UAV) in different realistic safety, security, and rescue field tests are presented. First, results from two safety and security missions at the 2009 European Land Robot Trials (ELROB) are presented. A UAV in form of an Airrobot AR100-B is used in a reconnaissance and in a camp security scenario. The UAV is capable of autonomous waypoint navigation using onboard GPS processing. A digital video stream from the vehicle is used to create photo maps—also known as mosaicking—in real time at the operator station. This mapping is done using an enhanced version of Fourier Mellin based registration, which turns out to be very fast and robust. Furthermore, results from a rescue oriented scenario at the 2010 Response Robot Evaluation Exercises (RREE) at Disaster City, Texas are presented. The registration for the aerial mosaicking is supplemented by an uncertainty metric and embedded into Simultaneous Localization and Mapping (SLAM), which further enhances the photo maps as main mission deliveries.     

Compositional specification of commercial contracts

We present a declarative language for compositional specification of contracts governing the exchange of resources. It extends Eber and Peyton Jones’s declarative language for specifying financial contracts (Jones et al. in The Fun of Programming. 2003) to the exchange of money, goods and services amongst multiple parties and complements McCarthy’s Resources, Events and Agents (REA) accounting model (McCarthy in Account Rev. LVII(3), 554–578, 1982) with a view- independent formal contract model that supports definition of user-defined contracts, automatic monitoring under execution and user-definable analysis of their state before, during and after execution. We provide several realistic examples of commercial contracts and their analyses. A variety of (real) contracts can be expressed in such a fashion as to support their integration, management and analysis in an operational environment that registers events. The language design is driven by both domain considerations and semantic language design methods: a contract denotes a set of traces of events, each of which is an alternative way of concluding the contract successfully, which gives rise to a CSP-style (Brooker et al. in J.ACM 31(3), 560–599, 1984; Hoare in Communicating Sequential Processes, 1985) denotational semantics. The denotational semantics drives the development of a sound and complete small-step operational semantics, where a partially executed contract is represented as a (full) contract that represents the remaining contractual commitments. This operational semantics is then systematically refined in two stages to an instrumented operational semantics that reflects the bookkeeping practice of identifying the specific contractual commitment a particular event matches at the time the event occurs, as opposed to delaying this matching until the contract is concluded.     

Gender gaps in scientific performance: a longitudinal matching study of health sciences researchers

Scientometrics - The existence of gender disparities in academia is well documented. Many explanations have been proposed and productivity is one of the most used variables to explain a possible...     

Composition of bacterial and archaeal communities in freshwater sediments with different contamination levels (Lake Geneva, Switzerland)

The aim of this study was to compare the composition of bacterial and archaeal communities in contaminated sediments (Vidy Bay) with uncontaminated sediments (Ouchy area) of Lake Geneva using 16S rRNA clone libraries. Sediments of both sites were analysed for physicochemical characteristics including porewater composition, organic carbon, and heavy metals. Results show high concentrations of contaminants in sediments from Vidy. Particularly, high contents of fresh organic matter and nutrients led to intense mineralisation, which was dominated by sulphate-reduction and methanogenesis. The bacterial diversity in Vidy sediments was significantly different from the communities in the uncontaminated sediments. Phylogenetic analysis revealed a large proportion of Betaproteobacteria clones in Vidy sediments related to Dechloromonas sp., a group of dechlorinating and contaminant degrading bacteria. Deltaproteobacteria, including clones related to sulphate-reducing bacteria and Fe(III)-reducing bacteria (Geobacter sp.) were also more abundant in the contaminated sediments. The archaeal communities consisted essentially of methanogenic Euryarchaeota, mainly found in the contaminated sediments rich in organic matter. Multiple factor analysis revealed that the microbial community composition and the environmental variables were correlated at the two sites, which suggests that in addition to environmental parameters, pollution may be one of the factors affecting microbial community structure.     

Dissolution of Alumina, Sintering, and Crystallization in Glass Ceramic Composites for LTCC

Sintering and microstructure evolution of alkali-free calcium–alumo–borosilicate glass/α-Al₂O₃ composites (mean particle size ca. 2 μm) for low-temperature cofired ceramics were studied during heating at 5 K/min by heating microscopy, thermal analysis (DTA), X-ray diffraction (XRD), and electron microscopy (SEM). Composites fully densify at ≈830°C, not essentially influenced by the dissolution of alumina and glass crystallization. Thus wollastonite, as first crystalline phase, was detectable at 840°C. Above 900°C, a pronounced crystallization of anorthite is evident, reaching 60 wt% at 1050°C. Rietveld analyses of XRD data revealed that anorthite precipitates at the expenses of alumina, which declines from ≈33 to <10 wt%, and wollastonite, which fully declines from its maximum of ≈19 wt%. Based on XRD, we discuss the evolution of crystal mass fractions, the residual glass composition, the glass viscosity, and the effective shear viscosity of the composites under study during heating.     

Double hashing with passbits

Double hashing with bucket capacity one is augmented with multiple passbits to obtain significant reduction to unsuccessful search lengths. This improves the analysis of Martini et al. [P.M. Martini, W.A. Burkhard, Double hashing with multiple passbits, Internat. J. Found. Theoret. Comput. Sci. 14 (6) (2003) 1165-1188] by providing a closed form expression for the expected unsuccessful search lengths.     

Extremely low threshold current 1.52 ?m InGaAsP/InP MS-DFB lasers with second-order grating

Threshold currents of 1.52 ?m InGaAsP/InPGaAsP/InP DFB lasers with second-order gratings have been reduced to 12 mA in single-longitudinal-mode operation. External differential efficiencies exceed 25%/feet with a ?/4 Si3N4 coating on the front facet.