Adaptive Ground Clutter Removal Algorithm for Ground Penetrating Radar Applications in Harsh Environments

In this work we present a novel adaptive ground clutter removal (AGCR) algorithm for ground penetrating radar (GPR) applications. The reduction or even removal of the disturbing ground clutter, which mostly obscures the wanted reflections of buried targets, is very important especially for the detection of shallowly buried anti-personnel mines (APMs). Most of the ground clutter removal algorithms used nowadays, show weak performances in the case of a rough ground surface or suffer from high computation complexity. This algorithm is not designed to detect flush buried APMs. Further work is needed to ensure that the algorithm can detect all APM mines from flush buried to the maximum depth of cover of 13 cm as required by the UN SOPs. The algorithm presented in this contribution is capable to remove the ground clutter resulting from undulated surfaces by estimating not only the position but also the varying signal shape. This technique enables a near optimal ground clutter reduction with a moderate computation complexity. Furthermore, the proposed AGCR algorithm preserves the characteristic impulse responses of the buried objects, which affords a following target classification based on these significant reflections. The performance improvements of the proposed AGCR algorithm compared to standard algorithms are shown on measured data. The GPR data were collected with a laboratory test set-up which is also described briefly in this work.     

Clustered and deep echo state networks for signal noise reduction

Machine Learning - Echo State Networks (ESNs) are Recurrent Neural Networks with fixed input and internal (hidden) weights, and adaptable output weights. The hidden part of an ESN can be considered...     

Applicability of stable isotope fractionation analysis for the characterization of benzene biodegradation in a BTEX-contaminated aquifer

In recent years the analysis of stable isotope fractionation has increasingly been used for characterizing and quantifying biodegradation of contaminants in aquifers. The correlation of carbon and hydrogen isotope signatures of benzene in a BTEX-contaminated aquifer located in the area of a former hydrogenation plant gave indications that biodegradation mainly occurred under anoxic conditions. This finding was consistent with the investigation of hydrogeochemical conditions within the aquifer. Furthermore, the biodegradation of benzene was calculated by changes in carbon isotope signatures using the Rayleigh-equation-streamline approach. Since contaminant concentrations can be also affected by nonisotope-fractionating abiotic processes such as dilution, volatilization, or irreversible sorption to the aquifer matrix, the Rayleigh-equation-streamline approach was adjusted for scenarios assuming that biodegradation and abiotic processes occur either consecutively or simultaneously along a groundwater flow path between contaminant source and sampling well. The results of the scenarios differed significantly, indicating that an abiotic process (typically dilution) causes a decrease in benzene concentration within the investigated aquifer transect. This comparison of results derived from the different scenarios can help to identify whether biodegradation is the predominant process for decrease in contaminant concentration. However, for a proper quantification of biodegradation, the temporal sequence between biodegradation and dilution needs to be known. The uncertainty associated with the quantification of pollutant biodegradation by the Rayleigh-equation-streamline approach increases when nonisotope-fractionating abiotic processes cause a significant decrease in contaminant concentrations.     

Sensitive detection of anaerobic monochlorobenzene degradation using stable isotope tracers

Microbial degradation of monochlorobenzene (MCB) under anaerobic conditions was investigated using a stable isotope tracer under in and ex situ conditions. In situ microcosms were incubated directly in an anoxic aquifer and carbon derived from [13C6]-MCB was found to be incorporated into the microbial biomass. In laboratory microcosms, amended with [13C6]-MCB, anaerobic mineralization of MCB was indicated by the production of 13CO2. Further, recovery of the 13C-label in the fatty acids confirmed the assimilation of MCB-derived carbon into microbial biomass. The described approach may be applied to various other organic groundwater contaminants of concern using carbon (13C) as well as other stable isotope tracers, such as nitrogen (15N), allowing direct and sensitive detection of biodegradation.     

Spritzbeton — der etwas andere Beton

Shotcrete — a special Concrete Analysis of Material Behaviour and Tests Shotcrete is one of the main support measures when doing excavational works according to the “New Austrian Tunnelling Method” (NATM). The peculiarity of a support made of shotcrete is that the young shotcrete, which runs through the hydration process, is subjected to rather large constraints. The estimation of the load bearing capability of shotcrete in comparison to the actual degree of loading needs the knowledge about its time dependent strength and the actual stress state. The problematic stress monitoring using hydraulic stress cells is replaced by the introduction of a time‐dependent stress — strain relationship and displacement resp. strain monitoring. This approach enables the calculation of the actual stresses via the strains which are derived from the monitoring data.     

ALOHA: Automatic libraries of helicity amplitudes for Feynman diagram computations

We present an application that automatically writes the Helas (HELicity Amplitude Subroutines) library corresponding to the Feynman rules of any quantum field theory Lagrangian. The code is written in Python and takes the Universal FeynRules Output (Ufo) as an input. From this input it produces the complete set of routines, wave-functions and amplitudes, that are needed for the computation of Feynman diagrams at leading as well as at higher orders. The representation is language independent and currently it can output routines in Fortran, C++, and Python. A few sample applications implemented in the MadGraph 5 framework are presented.Program summaryProgram title: ALOHACatalogue identifier: AEMS_v1_0Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEMS_v1_0.htmlProgram obtainable from: CPC Program Library, Queen’s University, Belfast, N. IrelandLicensing provisions: http://www.opensource.org/licenses/UoI-NCSA.phpNo. of lines in distributed program, including test data, etc.: 6094320No. of bytes in distributed program, including test data, etc.: 7479819Distribution format: tar.gzProgramming language: Python2.6Computer: 32/64 bitOperating system: Linux/Mac/WindowsRAM: 512 MbytesClassification: 4.4, 11.6Nature of problem:An effcient numerical evaluation of a squared matrix element can be done with the help of the helicity routines implemented in the HELAS library [1]. This static library contains a limited number of helicity functions and is therefore not always able to provide the needed routine in the presence of an arbitrary interaction. This program provides a way to automatically create the corresponding routines for any given model.Solution method:ALOHA takes the Feynman rules associated to the vertex obtained from the model information (in the Ufo format [2]), and multiplies it by the different wavefunctions or propagators. As a result the analytical expression of the helicity routines is obtained. Subsequently, this expression is automatically written in the requested language (Python, Fortran or C++)Restrictions: The allowed fields are currently spin 0, 1/2, 1 and 2, and the propagators of these particles are canonical.Running time: A few seconds for the SM and the MSSM, and up to a few minutes for models with spin 2 particles.References:[1] Murayama, H. and Watanabe, I. and Hagiwara, K., Helas: HELicity Amplitude Subroutines for Feynman diagram evaluations, KEK-91-11, (1992) http://www-lib.kek.jp/cgi-bin/img_index?199124011[2] C. Degrande, C. Duhr, B. Fuks, D. Grellscheid, O. Mattelaer, et al., Ufo— The Universal FeynRules Output, Comput. Phys. Commun. 183 (2012) 1201-1214. arXiv:1108.2040, doi:10.1016/j.cpc.2012.01.022.     

Mode I delamination fatigue crack growth in unidirectional fiber reinforced composites: Development of a standardized test procedure

Selected mode I fatigue data from five different types of fiber-reinforced, polymer–matrix composites tested in two round robins organized by the American Society for Testing and Materials subcommittee D30.06 and European Structural Integrity Society Technical Committee 4, respectively, are analyzed and discussed. The focus is on experimental scatter (in-laboratory and inter-laboratory) and on schemes for quantitative data analysis. It is shown that in spite of considerable scatter different composites can be distinguished and, under certain assumptions, a relative ranking be established. Further, effects from limited experimental measurement resolution are noted and implications for the test procedure and use of the test data in design of composite structures discussed. For comparative purposes, a rough ranking of different composites is feasible with test data generated within 24 h per specimen in an industrial test environment.     

Existing Building Challenge and CONCERTO Project

If Europe is to achieve the planned transition to a low carbon economy by 2050, succeeding in improving the energy efficiency of the largely inefficient existing building stock will be pivotal. Certain energy efficiency retrofitting obligations have now emerged as part of the EU＇s Energy Performance in Buildings Directive and the Energy Efficiency Directive. Challenges for retrofitting currently include gaps in technical skills both amongst building trades and professionals, a lack of awareness of building owners and users, concerns about compromising cultural heritage as well as a lack of viable business models, comparatively high cost and resulting long pay-back periods currently hamper the progress. Lessons can be drawn here form the EU-funded initiative CONCERTO, which helped 58 communities in 23 countries to reduce their dependence on conventional energy supply by implementing energy efficiency measures and integrating renewable energy sources not at single building scale but community scale. Almost all of these entailed retrofitting activities bad to find solutions to the issues mentioned. This paper presents a selection of conclusions regarding retrofitting to be drawn from the analysis undertaken under the project CONCERTO premium, which analysed outcomes across the 58 projects on behalf of the European Commission and focuses in particular on the political relevance of outcomes.