W‐band physical layer design issues in the context of the DAVID–DCE experiment

This paper aims at focusing on the aspects concerning the physical layer design for an innovative satellite communication experiment. Such an experiment, denoted by the acronym DAVID–DCE (Data and Video Interactive Distribution—Data Collection Experiment) is based on the exploitation of the W‐band (75–110 GHz) for high‐bit‐rate satellite transmission. The potential advantages of using of the W‐band are mainly related to the great bandwidth availability, and to the absence of interference. Moreover, an expected result of the experiment is a substantive improvement in the communication system's performances in the presence of meteorological phenomena (e.g. rain) as compared with the more conventional Ka‐band satellite transmission. On the other hand, problems to be faced concern the non‐ideal behaviours of hardware devices employed for high‐frequency digital transmission. In particular, carrier recovery and timing recovery are the most crucial signal‐processing tasks to be carefully considered in the design of the physical level of the system, because they considerably suffer from hardware impairments. The purpose of this work is to illustrate the proposed solutions in terms of the most critical modulation, demodulation and synchronization design issues, together with the effects of non‐ideal behaviours of hardware components on BER performances. Copyright © 2004 John Wiley & Sons, Ltd.     

Proton nuclear magnetic resonance rapid and structure-specific determination ofω-3 polyunsaturated fatty acids in fish lipids

Based on proton nuclear magnetic resonance (¹H-NMR) spectroscopy, a rapid and structure-specific method for the determination of ω-3 polyunsaturated fatty acids (PUFAs) in fish lipids is presented. The different chemical shift observed for the methyl resonance of ω-3 PUFAs (δ=0.95 ppm) with respect to the methyl resonance of all other fatty acids (δ=0.86 ppm) has provided the possibility of proposing a new and rapid method for the determination of ω-3 PUFA content. Twenty-four fish lipid samples (raw, cooked and canned albacore tuna) produced results that showed good agreement between¹H-NMR analysis and gas chromatographic determination. Raw and cooked samples showed significantly higher levels of ω-3 PUFA than canned tuna.     

Polymeric dispersions of model azobenzene dyes

New host-guest systems were prepared by using poly(vinyl acetate) and different ethylene-vinyl acetate copolymers as polymeric hosts because of their good compatibility with polar molecules. Two symmetric azobenzene diesters, that is 4,4′-dicarboxyethylazobenzene and 4,4′-di(2-ethylhexyloxycarbonyl)azobenzene were selected as guests. Both solution casting and melt processing were adopted for the preparation of dispersion films that were thoroughly characterized by thermal analysis, UV-vis and FT-IR spectroscopy, and by polarized optical microscopy. The reported results indicate that solution casting afforded heterogeneous dispersions of dye microcrystals at guest concentrations larger than 0.3% whereas homogeneous colored films were obtained at lower dye contents. On the other hand, both melt processing and the presence of branched diester groups favored the dye dispersion within the polymer matrix. At 0.1% dye content, the adopted preparation technique did not appreciably affect the film properties. After 4-8 fold stretching, the host-guest films were analyzed by polarized light spectroscopy. Some of the investigated films displayed interesting polarization efficiency, potentially suited for the preparation of thin film polarizers.     

Available niacin content in processed legumes

Summary There different legumes, chick peas, kidney beans, and lentils, were soaked and boiled in distilled water under normal and high pressure. The cooked legumes were kept at 35° C for 5 h, simulating catering systems, and the niacin contents were determined by HPLC. Data were obtained for raw and boiled legumes on both a wet weight and a dry matter basis. The niacin content of the raw legumes on a wet weight basis was always higher than that of the processed legumes, but on a dry matter basis there were small, though occasionally significant, increases in niacin content. In most cases simulated catering also led to a significant increase in the available niacin.

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Gehalt an verfügbarem Niacin in verarbeiteten Hülsenfrüchten

Zusammenfassung Drei verschiedene Hülsenfrüchte, Kichererbsen, Schminkbohnen und Linsen, wurden in destilliertem Wasser eingeweicht und anschließend unter normalem und erhöhtem Druck gekocht. Zur Simulation eines Catering-Systemes wurden die gekochten Hülsenfrüchte 5 h bei 35 °C gelagert. In den rohen, den gekochten und den gelagerten Hülsenfrüchten wurde der Niacingehalt mittels Hochleistungsflüssigchromatographie (HPLC) bestimmt. Die erhaltenen Resultate zeigten, daß der Gehalt an verfügbarem Niacin, bezogen auf das Frischgewicht des Rohmaterials, durch den Kochprozeß in jedem Falle vermindert wird. Auf Trockensubstanz bezogen wurden kleine, zum Teil signifikante, Erhöhungen des Niacingehaltes gegenüber dem Rohmaterial beobachtet. Die Simulation von Catering-Bedingungen führte ebenfalls in den meisten Fällen zu einer signifikanten Erhöhung des verfügbaren Niacins.

     

REVISE: A Tool for Measuring and Mitigating Bias in Visual Datasets

International Journal of Computer Vision - Machine learning models are known to perpetuate and even amplify the biases present in the data. However, these data biases frequently do not become...     

A study to support agile methods more effectively through traceability

Traceability is recognized to be important for supporting agile development processes. However, after analyzing many of the existing traceability approaches it can be concluded that they strongly depend on traditional development process characteristics. Within this paper it is justified that this is a drawback to support adequately agile processes. As it is discussed, some concepts do not have the same semantics for traditional and agile methodologies. This paper proposes three features that traceability models should support to be less dependent on a specific development process: (1) user-definable traceability links, (2) roles, and (3) linkage rules. To present how these features can be applied, an emerging traceability metamodel (TmM) will be used within this paper. TmM supports the definition of traceability methodologies adapted to the needs of each project. As it is shown, after introducing these three features into traceability models, two main advantages are obtained: 1) the support they can provide to agile process stakeholders is significantly more extensive, and 2) it will be possible to achieve a higher degree of automation. In this sense it will be feasible to have a methodical trace acquisition and maintenance process adapted to agile processes.     

A computational study of parametric tabu search for 0–1 mixed integer programs

We present a computational study of parametric tabu search for solving 0–1 mixed integer programming (MIP) problems, a generic heuristic for general MIP problems proposed by Glover [Glover F. Parametric tabu-search for mixed integer programs. Computers and Operations Research 2006; 33: 2449–94.]. This approach solves a series of linear programming problems by incorporating branching inequalities as weighted terms in the objective function. New strategies are proposed for uncovering feasible and high-quality solutions and extensive computational tests are performed on instances from the literature.     

Experimental setup for lensless imaging via soft x-ray resonant scattering

We have developed a setup for measuring holographically formed interference patterns using an integrated sample-mask design. The direct space image of the sample is obtained via a two-dimensional Fourier transform of the X-ray diffraction pattern. We present the details of our setup, commenting on the influence of geometrical parameters on the imaging capabilities. As an example, we present and discuss the results of test experiments on a patterned Co film.     

Detection of Salmonella in food,feed and veterinary samples by EU laboratories

The European Union Reference Laboratory (EURL) for Salmonella organises interlaboratory comparison studies on bacteriological detection of Salmonella in different matrices (veterinary, food and animal feed) amongst National Reference Laboratories for Salmonella of the 27 European Member States (EU-MS). The EURL also gives non-EU Member States (EU candidate countries, member countries of the European Free Trade Association (EFTA) and third countries from outside Europe) the opportunity to participate in these studies. The objective of the studies is to test the ability of the participating laboratories to detect Salmonella at different contamination levels in the various matrices. In addition a comparison is made between the prescribed method of the food and animal feed studies (ISO 6579: RVS and MKTTn) and the prescribed method of the veterinary studies (annex D of ISO 6579: MSRV).This article describes the performance of the individual laboratories in the interlaboratory comparison studies as organised by the EURL for Salmonella in the period 2004-2010.The performance of the majority of the NRLs improved during the course of the studies. Overall the NRL laboratories performed well and were able to detect Salmonella in the different tested matrices. After improvement of the samples, it was possible to define criteria for good performance in the studies organised since 2006. In the eight interlaboratory comparison studies organised in the period 2006–2010, 15 laboratories found in total 19 deviations of which eight concerned a false positive blank result. The other deviations concerned sensitivity problems (false negative results). After checking and improving several technical aspects, the underperforming participating laboratories were able to improve their performance in a follow-up study.